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16 pages, 1570 KiB

Open AccessArticle

Effect of Water Supplementation on Oxidant/Antioxidant Activities and Total Phenol Content in Growing Olives of the Morisca and Manzanilla Varieties

by Inmaculada Garrido, Marcos Hernández, José Luis Llerena and Francisco Espinosa

Antioxidants 2022, 11(4), 729; https://doi.org/10.3390/antiox11040729 - 07 Apr 2022

Cited by 1 | Viewed by 1522

Abstract

The objective of this work was to analyse, using a time series analysis, the effect of water regime for two cultivars at three stages of ripeness, during three consecutive years. Fruit and oil yield; O₂⁻ production and NADH oxidation activities; polyphenol [...] Read more.

The objective of this work was to analyse, using a time series analysis, the effect of water regime for two cultivars at three stages of ripeness, during three consecutive years. Fruit and oil yield; O₂⁻ production and NADH oxidation activities; polyphenol oxidase (PPO), superoxide dismutase (SOD) and peroxidase (POX) activities; total phenols, flavonoid and phenylpropanoid glycoside content; and total antioxidant capacity (FRAP) were determined. All these parameters were found to depend on variety, irrigation and year. The results showed that the fruit and oil yields were strongly dependent on both irrigation and variety. The DW/FW ratio was practically constant during ripening, with small variety-dependent changes due to irrigation. Total amino acid and protein contents increased with ripening, with a close dependence on variety but not on irrigation. The SOD and POX activities appeared closely related, and related to the NADH oxidation and the amount of O₂⁻. The evolution of phenols and FRAP during ripening was complementary to that of NADH oxidation, O₂⁻ production as well as SOD and POX activities. The determining factors of the SOD, POX and PPO activities were the variety and the ripening; the determining factor of the yield, ROS production, total phenols and antioxidant capacity was the water regime. Inverse correlations were observed between maximum temperature and total phenols (−0.869), total flavonoids (−0.823), total PPGs (−0.801) and FRAP (−0.829); and between DW/FW and irrigation (−0.483). The remaining significant correlations were positive. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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19 pages, 902 KiB

Open AccessArticle

Quantitatively Unraveling Hierarchy of Factors Impacting Virgin Olive Oil Phenolic Profile and Oxidative Stability

by Maja Jukić Špika, Zlatko Liber, Cinzia Montemurro, Monica Marilena Miazzi, Ivica Ljubenkov, Barbara Soldo, Mirella Žanetić, Elda Vitanović, Olivera Politeo and Dubravka Škevin

Antioxidants 2022, 11(3), 594; https://doi.org/10.3390/antiox11030594 - 20 Mar 2022

Cited by 9 | Viewed by 2434

Abstract

A single phenolic group and even a compound play different roles in the sensory properties and stability of virgin olive oil (VOO), which in turn are strongly influenced by several factors. Understanding the causes of differences in phenolic compound composition and oxidative stability [...] Read more.

A single phenolic group and even a compound play different roles in the sensory properties and stability of virgin olive oil (VOO), which in turn are strongly influenced by several factors. Understanding the causes of differences in phenolic compound composition and oxidative stability (OS) in VOOs is essential for targeted and timely harvest and processing while maintaining desired oil quality. The phenolic profile and OS of two monocultivar VOOs (Oblica and Leccino) grown in two geographical sites of different altitudes (coastal plain and hilly hinterland) were analyzed throughout the ripening period over two years. Concentration of secoiridoids was 30% higher in the Oblica than in the Leccino VOOs, which in turn had significantly higher values of OS. Both cultivars had more than twice as high concentrations of the two most abundant phenolic compounds, the dialdehyde form of decarboxymethyl oleuropein aglycone and the dialdehyde form of decarboxymethyl ligstroside aglycone, and OS values in a colder growing site of higher altitude. Among the studied monocultivar VOOs, the secoiridoid group did not behave equally during ripening. The hierarchy of different influencing factors was investigated using multivariate statistics and revealed: cultivar > geographical site > harvest period > growing season. In addition, the possibility of traceability of VOO using molecular markers was investigated by establishing SSR profiles of oils of the studied cultivars and comparing them with SSR profiles of leaves. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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20 pages, 2761 KiB

Open AccessArticle

Influence of Blanching on the Gene Expression Profile of Phenylpropanoid, Flavonoid and Vitamin Biosynthesis, and Their Accumulation in Oenanthe javanica

by Sunjeet Kumar, Xinfang Huang, Qun Ji, Abdul Qayyum, Kai Zhou, Weidong Ke, Honglian Zhu and Guopeng Zhu

Antioxidants 2022, 11(3), 470; https://doi.org/10.3390/antiox11030470 - 26 Feb 2022

Cited by 10 | Viewed by 2656

Abstract

Field blanching is a process used in agriculture to obtain sweet, delicious, and tender stems of water dropwort by obstructing sunlight. The nutritional and transcriptomic profiling of blanched water dropwort has been investigated in our previous studies. However, the effect of blanching on [...] Read more.

Field blanching is a process used in agriculture to obtain sweet, delicious, and tender stems of water dropwort by obstructing sunlight. The nutritional and transcriptomic profiling of blanched water dropwort has been investigated in our previous studies. However, the effect of blanching on the production of secondary metabolites and different vitamins in water dropwort has not been investigated at the transcriptomic level. This study explored the transcriptomic variations in the phenylpropanoid biosynthesis, flavonoid biosynthesis, and different vitamin biosynthesis pathways under different blanching periods in the water dropwort stems (pre-blanching, mid-blanching, post-blanching, and control). The results show that polyphenol and flavonoid contents decreased; however, the contents of vitamins (A, B1, B2, and C) and antioxidant activity increased significantly after blanching. Furthermore, the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of blanched water dropwort showed the downregulation of many important genes involved in phenylpropanoid and flavonoid biosynthesis pathways, and the downregulation of these genes might be the reason for the reduction in polyphenol and flavonoid contents. We also examined and highlighted the genes involved in the higher vitamin content, antioxidant activity, pale color, tenderness, and sweetness of the blanched stem of water dropwort. In conclusion, the present study explored the role of phenylpropanoid and vitamin biosynthesis, and it will provide a basis for future investigation and application in the blanch cultivation of water dropwort. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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23 pages, 12908 KiB

Open AccessArticle

Potential Valorization of Edible Nuts By-Products: Exploring the Immune-Modulatory and Antioxidants Effects of Selected Nut Shells Extracts in Relation to Their Metabolic Profiles

by Mohamed A. Salem, Nora M. Aborehab, Ahmed A. Al-Karmalawy, Alisdair R. Fernie, Saleh Alseekh and Shahira M. Ezzat

Antioxidants 2022, 11(3), 462; https://doi.org/10.3390/antiox11030462 - 25 Feb 2022

Cited by 27 | Viewed by 2989

Abstract

The immune system is a potent army that defends our body against various infections and diseases through innate and adaptive immunity. Herbal medicine is one of the essential sources for enhancing immunity because of affordability, availability, minor side effects, and consumers’ preferences. Hazelnuts, [...] Read more.

The immune system is a potent army that defends our body against various infections and diseases through innate and adaptive immunity. Herbal medicine is one of the essential sources for enhancing immunity because of affordability, availability, minor side effects, and consumers’ preferences. Hazelnuts, walnuts, almonds, and peanuts are among the most widespread edible nuts that are rich in phenolics, fats, fibers, vitamins, proteins, and minerals. The potential of nut shells in phytoremediation has attracted increasing attention as a sustainable solution for waste recycling. Here, we determined the in vitro immune-modulatory activity as well as the metabolite profile of the four nut shell extracts. The addition of the extracts to LPS-stimulated macrophages, especially peanut and walnut shells, has downregulated the gene expression of AP-1, TNF-α, IL-8, iNOS, and COX-2 expression levels. Significant antioxidant capabilities and immune-modulatory effects have been traced for peanut shells. UPLC-MS metabolic profiling of the four nut shell extracts allowed the detection of a relatively high level of phenolic compounds in peanut shells. Intriguingly, a significant correlation between the antioxidant capacity and the total phenolic content was found, indicating the contribution of the phenolic compounds to the antioxidant properties and hence the immune-modulatory activity. Furthermore, molecular docking and structure–activity relationship (SAR) studies revealed kaempferol rutinoside and proanthocyanidin A5’ as potential iNOS inhibitors. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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17 pages, 3373 KiB

Open AccessArticle

Comparison of Various Solvent Extracts and Major Bioactive Components from Portulaca oleracea for Antioxidant, Anti-Tyrosinase, and Anti-α-Glucosidase Activities

by Wei-Cheng Chen, Shih-Wei Wang, Cai-Wei Li, Hsiang-Ru Lin, Chang-Syun Yang, Yi-Cheng Chu, Tzong-Huei Lee and Jih-Jung Chen

Antioxidants 2022, 11(2), 398; https://doi.org/10.3390/antiox11020398 - 16 Feb 2022

Cited by 19 | Viewed by 3767

Abstract

Portulaca oleracea is a well-known species for traditional medicine and food homology in Taiwan. In traditional medicine, P. oleracea is also used to treat gastrointestinal disorders, liver inflammation, fever, severe inflammation, and headaches. We investigated antioxidant, anti-tyrosinase, and anti-α-glucosidase activities of various solvent [...] Read more.

Portulaca oleracea is a well-known species for traditional medicine and food homology in Taiwan. In traditional medicine, P. oleracea is also used to treat gastrointestinal disorders, liver inflammation, fever, severe inflammation, and headaches. We investigated antioxidant, anti-tyrosinase, and anti-α-glucosidase activities of various solvent extracts and major bioactive components from P. oleracea. Ethanol and acetone extracts showed potent DPPH, ABTS, and hydroxyl radical scavenging activities. Chloroform and n-hexane extracts displayed significant superoxide radical scavenging activity. Furthermore, ethyl acetate and acetone extracts of P. oleracea showed potent anti-tyrosinase and anti-α-glucosidase activities. Examined and compared to the various solvent extracts for their chemical compositions using HPLC analysis, we isolated seven major compounds and analyzed their antioxidant, anti-tyrosinase, and anti-α-glucosidase activities. Seven active compounds of P. oleracea, especially quercetin, rosmarinic acid, and kaempferol, exhibited obvious antioxidant, anti-tyrosinase, and anti-α-glucosidase activities. The molecular docking model and the hydrophilic interactive mode of tyrosinase and α-glucosidase revealed that active compounds might have a higher antagonistic effect than commonly inhibitors. Our result shows that the active solvent extracts and their components of P. oleracea have the potential as natural antioxidants, tyrosinase and α-glucosidase inhibitors. Our results suggest that the active solvent extracts of P. oleracea and their components have potential as natural antioxidants, tyrosinase and α-glucosidase inhibitors. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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17 pages, 6800 KiB

Open AccessArticle

Formulation of Gels and Emulgels with Malus domestica Borkh: Apple Extracts and Their Biopharmaceutical Evaluation In Vitro

by Aurita Butkeviciute, Kristina Ramanauskiene and Valdimaras Janulis

Antioxidants 2022, 11(2), 373; https://doi.org/10.3390/antiox11020373 - 12 Feb 2022

Cited by 8 | Viewed by 2441

Abstract

Phenolic compounds that estimate apple extracts with multifaceted biological effects are potentially valuable for protection against skin disorders. The purpose of our research was to formulate gels and emulgels containing a complex of phenolic compounds of apple extracts and to perform a biopharmaceutical [...] Read more.

Phenolic compounds that estimate apple extracts with multifaceted biological effects are potentially valuable for protection against skin disorders. The purpose of our research was to formulate gels and emulgels containing a complex of phenolic compounds of apple extracts and to perform a biopharmaceutical evaluation of semi-solid pharmaceutical forms, determining their antioxidant activity in vitro. HPLC analyses of phenolic compounds were performed. The total amount of phenolic compounds found in the sample of apples from the ‘Paprastasis antaninis’ cultivar was 1455.5 ± 72.8 µg/g. The release of phenolics from gels and emulgels was assessed by Franz-type diffusion cells. The in vitro release test revealed that phenolic compounds were released from the gel (G1–G6) formulations (70.6–73.8%) compared to the amounts (77.2–83.9%) released from the emulgel (E1–E6) formulations. The largest amount (83.9%) of phenolic compounds was released from the E5 formulation, while the smallest amounts (70.6%) were released from the formulations G3 and G5. The antioxidant activity evaluated by the DPPH and FRAP methods observed in all gel (G1–G6) and emulgel (E1–E6) formulations after 6 h were the strongest, compared to the activities observed in the formulations after 2 or 4 h. Gels and emulgels, which are rich in apple extracts, have strong antioxidant properties and may be promising choices for the development of new, innovative pharmaceutical forms or cosmetics. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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20 pages, 6055 KiB

Open AccessEditor’s ChoiceArticle

Phenolic Content and Antioxidant Activity in Apples of the ‘Galaval’ Cultivar Grown on 17 Different Rootstocks

by Aurita Butkeviciute, Vytautas Abukauskas, Valdimaras Janulis and Darius Kviklys

Antioxidants 2022, 11(2), 266; https://doi.org/10.3390/antiox11020266 - 28 Jan 2022

Cited by 12 | Viewed by 3451

Abstract

Apple cultivars are one of the main factors setting the composition of bioactive compounds in apples and the quality of the fruit. However, research has been providing increasing amounts of data on the influence of rootstocks on the variations in the composition of [...] Read more.

Apple cultivars are one of the main factors setting the composition of bioactive compounds in apples and the quality of the fruit. However, research has been providing increasing amounts of data on the influence of rootstocks on the variations in the composition of bioactive compounds in apples. The aim of the study was to determine the influence of rootstocks on the changes in the qualitative and quantitative composition of phenolic compounds and their antioxidant activity in vitro in apple flesh and peel. HPLC analyses of phenolic compounds in apple samples were performed. The rootstock–scion combination had a significant effect on the composition and antioxidant activity of phenolic compounds in apple samples. Depending on the rootstock, the total content of phenolic compounds in apple flesh of the ‘Galaval’ cultivar could vary by 2.9 times, and in the peel by up to 90%. The genotype of the rootstock resulted in the highest variation in total flavan-3-ol content in apple flesh—by as much as 4.3 times—while the total content of flavonols varied by 2.1 times. In apple peel, on the contrary, the greatest variation was recorded for the total flavonol content (by 4.4 times), and the total flavan-3-ol content varied the least (by 1.8 times). A proper match of a cultivar and a rootstock can program a fruit tree to grow larger amounts of higher-quality, antioxidant-rich, and high-nutrition-value fruit. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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23 pages, 3155 KiB

Open AccessArticle

Chemometric Classification of Cocoa Bean Shells Based on Their Polyphenolic Profile Determined by RP-HPLC-PDA Analysis and Spectrophotometric Assays

by Olga Rojo-Poveda, Giuseppe Zeppa, Ilario Ferrocino, Caroline Stévigny and Letricia Barbosa-Pereira

Antioxidants 2021, 10(10), 1533; https://doi.org/10.3390/antiox10101533 - 27 Sep 2021

Cited by 10 | Viewed by 2634

Abstract

The cocoa bean shell (CBS), a byproduct from the cocoa industry, was recently proposed as a functional and low-cost ingredient, mainly because of its content in polyphenols. However, vegetal food products could significantly differ in their chemical composition depending on different factors such [...] Read more.

The cocoa bean shell (CBS), a byproduct from the cocoa industry, was recently proposed as a functional and low-cost ingredient, mainly because of its content in polyphenols. However, vegetal food products could significantly differ in their chemical composition depending on different factors such as their geographical provenience. This work is aimed to determine the polyphenolic and methylxanthine profile of different CBS samples and utilize it for achieving their differentiation according to their geographical origin and variety. RP-HPLC-PDA was used to determine the CBS polyphenolic profile. Spectrophotometric assays were used to obtain the total phenolic, flavonoid, and tannin contents, as well as to evaluate their radical scavenging activity. The results obtained from both methods were then compared and used for the CBS differentiation according to their origin and varieties through chemometric analysis. RP-HPLC-PDA allowed to determine 25 polyphenolic compounds, as well as the methylxanthines theobromine and caffeine. Polyphenolic profile results highlighted significant differences among the analyzed samples, allowing for their differentiation based on their geographical provenience. Similar results were achieved with the results of the spectrophotometric assays, considered as screening methods. Differentiation based on CBS variety was instead obtained based on the HPLC-determined methylxanthine profile. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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23 pages, 7961 KiB

Open AccessArticle

Large-Scale Non-Targeted Metabolomics Reveals Antioxidant, Nutraceutical and Therapeutic Potentials of Sorghum

by Ajay Prasanth Ramalingam, Williams Mohanavel, Ameena Premnath, Raveendran Muthurajan, P. V. Vara Prasad and Ramasamy Perumal

Antioxidants 2021, 10(10), 1511; https://doi.org/10.3390/antiox10101511 - 23 Sep 2021

Cited by 13 | Viewed by 3851

Abstract

Sorghum is one of the most important food and feed cereal crops and has been gaining industrial importance in recent years for its biofuel, nutraceutical and antioxidant values. A genetic profile variation study was undertaken for the accumulation of phytochemicals in 61 diverse [...] Read more.

Sorghum is one of the most important food and feed cereal crops and has been gaining industrial importance in recent years for its biofuel, nutraceutical and antioxidant values. A genetic profile variation study was undertaken for the accumulation of phytochemicals in 61 diverse sorghum accessions differing in their growth habitat and grain color through non-targeted Gas Chromatography–Mass Spectrometry (GC-MS/MS) analysis. Mass Spectrometry–Data Independent AnaLysis (MS-DIAL) and MetaboAnalyst identified 221 metabolites belonging to 27 different phytochemicals. Tropical and temperate sorghums were distinct in their metabolic profiles with minimum overlaps, and 51 different metabolites were crucial in differentiating the two groups. Temperate sorghums had the ability to accumulate more of phenolic acids, phytosterols, flavonoids, carotenoids, and tropical sorghums for stress-related amino acids, sugars and fatty acids. Grain-color-based Partial Least Square–Discriminant Analysis (PLS-DA) analysis identified 94 Variable Importance in Projections (VIP) metabolites containing majority of flavonoids, phenylpropanoids and phytosterols. This study identified two sorghum lines (IS 7748 and IS 14861) with rich amounts of antioxidants (catechins and epicatechins) belonging to the group of condensed tannins that otherwise do not accumulate commonly in sorghum. Out of 13 metabolic pathways identified, flavonoid biosynthesis showed the highest expression. This study provided new opportunities for developing biofortified sorghum with enhanced nutraceutical and therapeutics through molecular breeding and metabolic engineering. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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15 pages, 2408 KiB

Open AccessArticle

Comparison of Antioxidant Properties of a Conjugate of Taxifolin with Glyoxylic Acid and Selected Flavonoids

by Victoria S. Shubina, Victoria I. Kozina and Yuri V. Shatalin

Antioxidants 2021, 10(8), 1262; https://doi.org/10.3390/antiox10081262 - 08 Aug 2021

Cited by 18 | Viewed by 4167

Abstract

It is known that flavonoids can react with toxic carbonyl compounds in the process of the storage, aging, and digestion of flavonoid-rich foods and beverages. However, the effect of these reactions on the antioxidant properties of the polyphenolic fraction and the properties of [...] Read more.

It is known that flavonoids can react with toxic carbonyl compounds in the process of the storage, aging, and digestion of flavonoid-rich foods and beverages. However, the effect of these reactions on the antioxidant properties of the polyphenolic fraction and the properties of the resulting products remain poorly studied. The aim of the present work was to study the antioxidant activity of quercetin, taxifolin, catechin, eriodictyol, hesperetin, naringenin and a product of the condensation of taxifolin with glyoxylic acid, as well as to reveal the structure–activity relationship of these polyphenols. It was found that flavonoids containing the catechol moiety exhibited higher antioxidant activity than hesperetin and naringenin. The product showed the highest hydrogen peroxide scavenging activity, a lower metal-reducing and a higher iron-binding ability than catechol-containing flavonoids, and a lipid peroxidation inhibitory activity comparable with that of taxifolin. Thus, the condensation of flavonoids with toxic carbonyl compounds might lead to the formation of products exhibiting high antioxidant activity. Meanwhile, the conditions under which parent flavonoids and their products exhibit the maximal antioxidant activity may differ. The data suggest that the antioxidant profile of the polyphenolic fraction and bioavailability of polyphenols, carbonyl compounds, and metal ions may change when these reactions occur. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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16 pages, 312 KiB

Open AccessArticle

LC-ESI/QTOF-MS Profiling of Chicory and Lucerne Polyphenols and Their Antioxidant Activities

by Yasir Iqbal, Eric N. Ponnampalam, Hafiz A. R. Suleria, Jeremy J. Cottrell and Frank R. Dunshea

Antioxidants 2021, 10(6), 932; https://doi.org/10.3390/antiox10060932 - 08 Jun 2021

Cited by 26 | Viewed by 3955

Abstract

Chicory and lucerne are used as specialised forages in sheep or dairy production systems in some parts of the world. Recently, these plants are gaining attention as raw materials in the search for natural antioxidants for use in animal feeds, human foods and [...] Read more.

Chicory and lucerne are used as specialised forages in sheep or dairy production systems in some parts of the world. Recently, these plants are gaining attention as raw materials in the search for natural antioxidants for use in animal feeds, human foods and nutraceutical formulations. The antioxidant potential of these plants is credited to polyphenols, a subgroup of phytochemicals. Therefore, phenolic characterisation is an essential step before their use as ingredients in animal feeds, human food or nutraceutical preparations. In this study, we performed qualitative and quantitative analysis of polyphenols in chicory and lucerne. Profiling of polyphenols from chicory and lucerne was performed by LC-ESI/QTOF-MS with a total of 80 phenolic compounds identified in chicory and lucerne. The quantification of polyphenols was achieved by high performance liquid chromatography, coupled with a photo diode array (HPLC-PDA). Chicoric acid was the major phenolic acid found in chicory, with the highest concentration (1692.33 ± 0.04 µg/g DW) among all the polyphenols quantified in this study. 2-hydroxybenzoic acid was the major phenolic acid found in lucerne, with the highest concentration of 1440.64 ± 0.04 µg/g DW. Total phenolic, flavonoids and total tannin contents were measured, and the antioxidant potential was determined by 2,2-Diphenyl-1-picrylhydrazyl, Ferric Reducing Antioxidant Power, 2,2-Azino-bis-3-ethylbenzothiazoline-6-sulfonic Acid, Hydroxyl (OH⁻) Radical Scavenging Activity, Chelating Ability of Ferrous Ion (Fe²⁺) and Reducing Power (RPA) assays. Both chicory (8.04 ± 0.33 mg AAE/g DW) and lucerne (11.29 ± 0.25 mg AAE/g DW) showed high values for Hydroxyl (OH⁻) Radical Scavenging Activity. The current study allowed us to draw a profile of polyphenols from chicory and lucerne. They provided a molecular fingerprint useful for the application of these plant materials in human foods, animal feeds and pharmaceutical formulations. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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21 pages, 2673 KiB

Open AccessArticle

Virgin Olive Oil Phenols, Fatty Acid Composition and Sensory Profile: Can Cultivar Overpower Environmental and Ripening Effect?

by Maja Jukić Špika, Slavko Perica, Mirella Žanetić and Dubravka Škevin

Antioxidants 2021, 10(5), 689; https://doi.org/10.3390/antiox10050689 - 27 Apr 2021

Cited by 30 | Viewed by 3136

Abstract

The authenticity and typicity of monocultivar oils and knowledge of the changes that environmental olive growing conditions bring to naturally present antioxidants and sensory attributes of virgin olive oils (VOO) are important for quality and safety improvement. This study delivers a comprehensive evaluation [...] Read more.

The authenticity and typicity of monocultivar oils and knowledge of the changes that environmental olive growing conditions bring to naturally present antioxidants and sensory attributes of virgin olive oils (VOO) are important for quality and safety improvement. This study delivers a comprehensive evaluation of the factors affecting phenolics, fatty acid composition and sensory characteristics of cultivars Oblica and Leccino VOOs throughout ripening season at two distinct olive growing environments during three consecutive crop years, and ranks the importance of each factor. Specified parameters were significantly influenced by olive growing environmental conditions. At the colder location of higher altitude, both cultivars gained higher amount of stearic, linoleic and linolenic fatty acids, as well as a higher proportion of phenolic compounds, but lower amounts of oleic fatty acid. At the warmer location of lower altitude, both cultivars had oils with lower level of fruitiness, bitterness and pungency. Analysis of the main components showed that VOOs were primarily differentiated by the cultivar, then main groups were divided with regard to the growing site, while harvest period affected the biosynthesis of natural VOOs antioxidants but had the least impact. These results reveal that the composition of fatty acids, phenolic content and sensory profile are predominantly characteristics of a cultivar. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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21 pages, 3040 KiB

Open AccessArticle

Phenolic Compounds of Reynoutria sp. as Modulators of Oral Cavity Lactoperoxidase System

by Marcin Magacz, Maria Oszajca, Izabela Nawrot-Hadzik, Ryszard Drożdż, Anna Jurczak, Jakub Hadzik, Aleksander Smakosz and Wirginia Krzyściak

Antioxidants 2021, 10(5), 676; https://doi.org/10.3390/antiox10050676 - 26 Apr 2021

Cited by 3 | Viewed by 2434

Abstract

Lactoperoxidase (LPO) together with its (pseudo)halogenation cycle substrates, H₂O₂ and thiocyanate ions oxidized to hypothiocyanite ions, form one of the main systems involved in antimicrobial defense within the oral cavity. In bacterial diseases such as dental caries, lactoperoxidase is oxidized [...] Read more.

Lactoperoxidase (LPO) together with its (pseudo)halogenation cycle substrates, H₂O₂ and thiocyanate ions oxidized to hypothiocyanite ions, form one of the main systems involved in antimicrobial defense within the oral cavity. In bacterial diseases such as dental caries, lactoperoxidase is oxidized to a form known as Compound II, which is characterized by its inability to oxidize SCN^–, resulting in a decreased generation of antimicrobial products. Reynoutria sp. rizome extracts, due to their high polyphenol content, have been tested as a source of compounds able to regenerate the antimicrobial activity of lactoperoxidase through converting the Compound II to the native LPO state. In the presented study, acetone extracts of R. japonica, R. sachalinensis, and R. x bohemica, together with their five fractions and four selected polyphenols dominating in the studied in extracts, were tested toward lactoperoxidase reactivating potential. For this purpose, IC50, EC50, and activation percentage were determined by Ellman’s method. Furthermore, the rate constants for the conversion of Compound I–Compound II and Compound II–native-LPO in the presence of extracts, extracts fractions, and selected polyphenols were determined. Finally, the ability to enhance the antimicrobial properties of the lactoperoxidase system was tested against Streptococcus mutans. We proved that Reynoutria sp. rhizome is the source of lactoperoxidase peroxidation cycle substrates, which can act as activators and inhibitors of the antimicrobial properties of that system. The presented study shows that the reactivation of lactoperoxidase could become a potential therapeutic target in prevention and treatment support in some infectious oral diseases. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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16 pages, 4275 KiB

Open AccessArticle

Phenolic Compounds from Carissa spinarum Are Characterized by Their Antioxidant, Anti-Inflammatory and Hepatoprotective Activities

by Ye Liu, Yongli Zhang, Felix Wambua Muema, Festus Kimutai, Guilin Chen and Mingquan Guo

Antioxidants 2021, 10(5), 652; https://doi.org/10.3390/antiox10050652 - 23 Apr 2021

Cited by 11 | Viewed by 3199

Abstract

Carissa spinarum has been traditionally used for the treatment of various diseases due to its different pharmacological activities. However, the active compounds responsible for its potentially specific activities have rarely been explored. To this end, the ethyl acetate (EA) fraction was screened out [...] Read more.

Carissa spinarum has been traditionally used for the treatment of various diseases due to its different pharmacological activities. However, the active compounds responsible for its potentially specific activities have rarely been explored. To this end, the ethyl acetate (EA) fraction was screened out and selected for further phytochemical isolation because of its promising activities in preliminary 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and COX-2 inhibition assays. As a result, 10 compounds (1−10), including a new one (5), were isolated, with eight of these being identified as phenolic compounds, as expected. Compound 9 possessed an IC₅₀ value of 16.5 ± 1.2 µM, which was lower than that of positive control (vitamin C, 25.5 ± 0.3 µM) in the DPPH assay, and compounds 2, 6, 7 and 9 showed better total antioxidant capacity than vitamin C in the FRAP assay. Meanwhile, compounds 1−6 and 9 also had IC₅₀ values of less than 1.0 µM, which was even better than the positive control indomethacin in the COX-2 inhibition assay. In this context, compounds 2 and 9 were further evaluated to exhibit clear hepatoprotective activities by improving the L02 cell viability and reducing ROS production using a H₂O₂-induced L02 cell injury model. This study provides initial evidence revealing the most potent phenolic compounds from the root bark of C. spinarum responsible for its antioxidant, anti-inflammatory and hepatoprotective activities. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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15 pages, 2217 KiB

Open AccessArticle

Effects of Cooking and Processing Methods on Phenolic Contents and Antioxidant and Anti-Proliferative Activities of Broccoli Florets

by Hee Young Kim, Meran Keshawa Ediriweera, Kyung-Hwan Boo, Chang Sook Kim and Somi Kim Cho

Antioxidants 2021, 10(5), 641; https://doi.org/10.3390/antiox10050641 - 22 Apr 2021

Cited by 13 | Viewed by 3696

Abstract

We investigated the effects of cooking (steaming and microwaving) and processing (freeze-drying and hot-air-drying) methods on the antioxidant activity of broccoli florets. 2,2-diphenyl-1-picrylhydrazyl (DPPH^•), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•), and alkyl^• free radical scavenging assays were employed to assess anti-oxidant [...] Read more.

We investigated the effects of cooking (steaming and microwaving) and processing (freeze-drying and hot-air-drying) methods on the antioxidant activity of broccoli florets. 2,2-diphenyl-1-picrylhydrazyl (DPPH^•), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•), and alkyl^• free radical scavenging assays were employed to assess anti-oxidant potentials. The cytoprotective effect against oxidative damage induced by H₂O₂ was studied using hepatocellular carcinoma (HepG2) cells. Anti-proliferative effects were assessed in MCF-7 and MDA-MB-231 breast cancer cells. L-sulforaphane in broccoli extracts was quantified using high-performance liquid chromatography (HPLC). Steam and microwave treatments caused increases in total polyphenol content (TPC), whereas the total flavonoid content (TFC) decreased following steam treatment. A slight increase in TFC was observed in the microwaved samples. Extracts of all broccoli samples showed almost identical radical scavenging and cytoprotective effects. HPLC demonstrated that steamed (3 min)-freeze-dried (F-S3) and microwaved (2 min)-freeze-dried (F-M2) samples exhibited elevated levels of L-sulforaphane. In addition, the F-S3 and F-M2 extracts displayed strong anti-proliferative effects in MCF-7 cells, which correlated with L-sulforaphane content. As we observed no significant decrease in the antioxidant activity of broccoli florets, the cooking and processing methods and conditions studied here are recommended for broccoli. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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24 pages, 6806 KiB

Open AccessArticle

The Effects of Prunus spinosa L. Flower Extracts, Model Polyphenols and Phenolic Metabolites on Oxidative/Nitrative Modifications of Human Plasma Components with Particular Emphasis on Fibrinogen In Vitro

by Anna Marchelak, Joanna Kolodziejczyk-Czepas, Paulina Wasielewska, Pawel Nowak and Monika A. Olszewska

Antioxidants 2021, 10(4), 581; https://doi.org/10.3390/antiox10040581 - 09 Apr 2021

Cited by 7 | Viewed by 2739

Abstract

Oxidative post-translational modifications of fibrinogen (a multifunctional blood plasma protein essential for hemostasis) are associated with the pathogenesis of cardiovascular disorders (CVDs). Prunus spinosa flower is a herbal medicine used in an adjuvant treatment of CVDs and rich in polyphenolic antioxidants. In the [...] Read more.

Oxidative post-translational modifications of fibrinogen (a multifunctional blood plasma protein essential for hemostasis) are associated with the pathogenesis of cardiovascular disorders (CVDs). Prunus spinosa flower is a herbal medicine used in an adjuvant treatment of CVDs and rich in polyphenolic antioxidants. In the present study, phytochemically standardized P. spinosa flower extracts, their primary native polyphenols and potential phenolic metabolites were evaluated in vitro for their protective effects on fibrinogen (isolated and in the human plasma matrix) using a panel of complementary methods (SDS-PAGE, western blot, C-ELISA, fluorometry, FRAP, TBARS). The results revealed that the tested analytes at in vivo relevant levels (1–5 µg/mL) considerably reduced the structural changes in the fibrinogen molecule under the oxidative stress conditions induced by peroxynitrite. In particular, they diminished the oxidation and/or nitration of amino acid residues, including tyrosine and tryptophan, as well as the formation of high molecular weight aggregates. The decrease in the levels of 3-nitrotyrosine was about 13.5–33.0% and 58.3–97.1% at 1 µg/mL and 50 µg/mL, respectively. The study indicated that low molecular weight polyphenols were crucial for the protective activity of the extracts toward fibrinogen and other human plasma components. The investigated model compounds effectively protected total plasma proteins and lipids against oxidative damage (by reducing the levels of 3-nitrotyrosine and thiobarbituric acid-reactive substances and normalizing/enhancing the non-enzymatic antioxidant capacity of plasma). The work provides insight into the role of native and metabolized polyphenols as contributory factors to the systemic activity of blackthorn flower extracts within the circulatory system. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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14 pages, 2449 KiB

Open AccessArticle

Phenolic Constituents of Chinese Quince Twigs (Chaenomeles sinensis Koehne) and Their Anti-Neuroinflammatory, Neurotrophic, and Cytotoxic Activities

by Dong Hyun Kim, Lalita Subedi, Hye Ryeong Kim, Sang Un Choi, Sun Yeou Kim and Chung Sub Kim

Antioxidants 2021, 10(4), 551; https://doi.org/10.3390/antiox10040551 - 02 Apr 2021

Cited by 5 | Viewed by 2769

Abstract

Chaenomeles sinensis has been used as a food and traditional medicines. However, most of research on discovering bioactive constituents from this plant have been focused on its yellow fruit, Chinese quince, due to its wide usage. Here, we isolated and characterized three new [...] Read more.

Chaenomeles sinensis has been used as a food and traditional medicines. However, most of research on discovering bioactive constituents from this plant have been focused on its yellow fruit, Chinese quince, due to its wide usage. Here, we isolated and characterized three new phenolic compounds (1, 9, and 11) and 21 known compounds (2−8, 10, and 12−24) from the twigs of C. sinensis. Their chemical structures were established by spectroscopic and spectrometric data analysis including 1D and 2D NMR, high-resolution mass spectrometry (HRMS), electronic circular dichroism (ECD), and LC-MS analysis. Some of the isolated compounds (1−24) showed anti-neuroinflammatory effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated BV-2 cells, neurotrophic activity in C6 cells through the secretion of nerve growth factor (NGF) and/or cytotoxicity against four human cancer cell lines (A549, SK-OV-3, SK-MEL-2, MKN-1). Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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17 pages, 2596 KiB

Open AccessArticle

Composition and Antioxidant Activity of Phenolic Compounds in Fruit of the Genus Rosa L.

by Mindaugas Liaudanskas, Irena Noreikienė, Kristina Zymonė, Rugilė Juodytė, Vaidotas Žvikas and Valdimaras Janulis

Antioxidants 2021, 10(4), 545; https://doi.org/10.3390/antiox10040545 - 01 Apr 2021

Cited by 27 | Viewed by 3004

Abstract

We investigated the qualitative and quantitative composition of phenolic compounds in the fruit of Rosa L. cultivars grown in Lithuania. The highest total content of phenolic compounds (50.13 ± 4.17 mg GAE/g, p < 0.05) was determined in fruit samples of Rosa pimpinellifolia [...] Read more.

We investigated the qualitative and quantitative composition of phenolic compounds in the fruit of Rosa L. cultivars grown in Lithuania. The highest total content of phenolic compounds (50.13 ± 4.17 mg GAE/g, p < 0.05) was determined in fruit samples of Rosa pimpinellifolia L. cultivar “Single Cherry”. The highest levels of hydroxycinnamic acid derivatives were determined in fruit samples of Rosa rugosa Thunb. cultivars “Dart’s Defender” and “Adam Chodun”. The highest flavonoid content was determined in fruit samples of Rosa multiflora Thunb. cultivar “Nana” and R. multiflora species. The strongest antioxidant activity evaluated by applying DPPH and FRAP assays was determined in fruit extracts of R. pimpinellifolia cultivar “Single Cherry” and R. rugosa cultivar “Adam Chodun”. Qualitative and quantitative analysis of phenolic compounds in Rosa L. fruit was performed by applying UHPLC. The following phenolic compounds were identified in fruit samples: caffeic acid, chlorogenic acid, quercetin, quercitrin, (+)-catechin, (−)-epicatechin, (−)-epicatechin gallate, rutin, phloridzin, and kaempferol-3-O-glycoside. A strong correlation was determined between the total amount of phenolic compounds determined in extracts of the fruit samples of Rosa L. cultivars and the radical scavenging and reducing activity of their extracts in vitro (R = 0.767 and 0.727, respectively, p < 0.05). Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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21 pages, 16461 KiB

Open AccessArticle

A Unique Acylated Flavonol Glycoside from Prunus persica (L.) var. Florida Prince: A New Solid Lipid Nanoparticle Cosmeceutical Formulation for Skincare

by Eman S. Mostafa, Ahmed Maher, Dalia A. Mostafa, Sameh S. Gad, Mahmoud A.M. Nawwar and Noha Swilam

Antioxidants 2021, 10(3), 436; https://doi.org/10.3390/antiox10030436 - 12 Mar 2021

Cited by 13 | Viewed by 3895

Abstract

Polyphenols are known dietary antioxidants. They have recently attracted considerable interest in uses to prevent skin aging and hyperpigmentation resulting from solar UV-irradiation. Prunus persica (L.) leaves are considered by-products and were reported to have a remarkable antioxidant activity due to their high [...] Read more.

Polyphenols are known dietary antioxidants. They have recently attracted considerable interest in uses to prevent skin aging and hyperpigmentation resulting from solar UV-irradiation. Prunus persica (L.) leaves are considered by-products and were reported to have a remarkable antioxidant activity due to their high content of polyphenols. This study aimed at the development of a cosmeceutical anti-aging and skin whitening cream preparation using ethanol leaves extract of Prunus persica (L.) (PPEE) loaded in solid lipid nanoparticles (SLNs) to enhance the skin delivery. Chemical investigation of PPEE showed significantly high total phenolic and flavonoids content with notable antioxidant activities (DPPH, ABTS, and β-carotene assays). A unique acylated kaempferol glycoside with a rare structure, kaempferol 3-O-β-⁴C₁-(6″-O-3,4-dihydroxyphenylacetyl glucopyranoside) (KDPAG) was isolated for the first time and its structure fully elucidated. It represents the first example of acylation with 3,4-dihydroxyphenyl acetic acid in flavonoid chemistry. The in-vitro cytotoxicity studies against a human keratinocytes cell line revealed the non-toxicity of PPEE and PPEE-SLNs. Moreover, PPEE, PPEE-SLNs, and KDPAG showed good anti-elastase activity, comparable to that of N-(Methoxysuccinyl)-Ala-Ala-Pro-Val-chloromethyl ketone. Besides, PPEE-SLNs and KDPAG showed significantly (p < 0.001) higher anti-collagenase and anti-tyrosinase activities in comparison to EDTA and kojic acid, respectively. Different PPEE-SLNs cream formulae (2% and 5%) were evaluated for possible anti-wrinkle activity against UV-induced photoaging in a mouse model using a wrinkle scoring method and were shown to offer a highly significant protective effect against UV, as evidenced by tissue biomarkers (SOD) and histopathological studies. Thus, the current study demonstrates that Prunus persica leaf by-products provide an interesting, valuable resource for natural cosmetic ingredients. This provides related data for further studying the potential safe use of PPEE-SLNs in topical anti-aging cosmetic formulations with enhanced skin permeation properties. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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19 pages, 2013 KiB

Open AccessArticle

Evaluation of Silicon and Proline Application on the Oxidative Machinery in Drought-Stressed Sugar Beet

by Muneera D. F. AlKahtani, Yaser M. Hafez, Kotb Attia, Emadeldeen Rashwan, Latifa Al Husnain, Hussah I. M. AlGwaiz and Khaled A. A. Abdelaal

Antioxidants 2021, 10(3), 398; https://doi.org/10.3390/antiox10030398 - 06 Mar 2021

Cited by 86 | Viewed by 4719

Abstract

Drought stress deleteriously affects growth, development and productivity in plants. So, we examined the silicon effect (2 mmol) and proline (10 mmol) individually or the combination (Si + proline) in alleviating the harmful effect of drought on total phenolic compounds, reactive oxygen species [...] Read more.

Drought stress deleteriously affects growth, development and productivity in plants. So, we examined the silicon effect (2 mmol) and proline (10 mmol) individually or the combination (Si + proline) in alleviating the harmful effect of drought on total phenolic compounds, reactive oxygen species (ROS), chlorophyll concentration and antioxidant enzymes as well as yield parameters of drought-stressed sugar beet plants during 2018/2019 and 2019/2020 seasons. Our findings indicated that the root diameter and length (cm), root and shoot fresh weights (g plant⁻¹) as well as root and sugar yield significantly decreased in sugar beet plants under drought. Relative water content (RWC), nitrogen (N), phosphorus (P) and potassium (K) contents and chlorophyll (Chl) concentration considerably reduced in stressed sugar beet plants that compared with control in both seasons. Nonetheless, lipid peroxidation (MDA), electrolyte leakage (EL), hydrogen peroxide (H₂O₂) and superoxide (O₂^●−) considerably elevated as signals of drought. Drought-stressed sugar beet plants showed an increase in proline accumulation, total phenolic compounds and up-regulation of antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) activity to mitigate drought effects. Si and proline individually or the combination Si + proline considerably increased root and sugar yield, sucrose%, Chl concentration and RWC, MDA and EL were remarkably reduced. The treatments led to adjust proline and total phenolic compounds as well as CAT and SOD activity in stressed sugar beet plants. We concluded that application of Si + proline under drought stress led to improve the resistance of sugar beet by regulating of proline, antioxidant enzymes, phenolic compounds and improving RWC, Chl concentration and Nitrogen, Phosphorus and Potassium (NPK) contents as well as yield parameters. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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22 pages, 5619 KiB

Open AccessArticle

Light and CO₂ Modulate the Accumulation and Localization of Phenolic Compounds in Barley Leaves

by Lena Hunt, Karel Klem, Zuzana Lhotáková, Stanislav Vosolsobě, Michal Oravec, Otmar Urban, Vladimír Špunda and Jana Albrechtová

Antioxidants 2021, 10(3), 385; https://doi.org/10.3390/antiox10030385 - 05 Mar 2021

Cited by 13 | Viewed by 3322

Abstract

Barley (Hordeum vulgare) accumulates phenolic compounds (PhCs), which play a key role in plant defense against environmental stressors as antioxidants or UV screening compounds. The influence of light and atmospheric CO₂ concentration ([CO₂]) on the accumulation and localization [...] Read more.

Barley (Hordeum vulgare) accumulates phenolic compounds (PhCs), which play a key role in plant defense against environmental stressors as antioxidants or UV screening compounds. The influence of light and atmospheric CO₂ concentration ([CO₂]) on the accumulation and localization of PhCs in barley leaves was examined for two varieties with different tolerances to oxidative stress. PhC localization was visualized in vivo using fluorescence microscopy. Close relationships were found between fluorescence-determined localization of PhCs in barley leaves and PhC content estimated using liquid chromatography coupled with mass spectroscopy detection. Light intensity had the strongest effect on the accumulation of PhCs, but the total PhC content was similar at elevated [CO₂], minimizing the differences between high and low light. PhCs localized preferentially near the surfaces of leaves, but under low light, an increasing allocation of PhCs in deeper mesophyll layers was observed. The PhC profile was significantly different between barley varieties. The relatively tolerant variety accumulated significantly more hydroxycinnamic acids, indicating that these PhCs may play a more prominent role in oxidative stress prevention. Our research presents novel evidence that [CO₂] modulates the accumulation of PhCs in barley leaves. Mesophyll cells, rather than epidermal cells, were most responsive to environmental stimuli in terms of PhC accumulation. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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16 pages, 1900 KiB

Open AccessFeature PaperArticle

Antioxidant Contributors in Seed, Seed Coat, and Cotyledon of γ-ray-Induced Soybean Mutant Lines with Different Seed Coat Colors

by You Jin Lim, Soon-Jae Kwon, Shanshan Qu, Dong-Gun Kim and Seok Hyun Eom

Antioxidants 2021, 10(3), 353; https://doi.org/10.3390/antiox10030353 - 26 Feb 2021

Cited by 17 | Viewed by 2779

Abstract

The development of soybean with high antioxidant activities for use in the food and cosmetics industries is a target of breeding programs. In soybean, antioxidants are associated with seed color, although the metabolic basis for seed coloration remains incompletely understood. We selected six [...] Read more.

The development of soybean with high antioxidant activities for use in the food and cosmetics industries is a target of breeding programs. In soybean, antioxidants are associated with seed color, although the metabolic basis for seed coloration remains incompletely understood. We selected six γ-ray-induced mutant lines that exhibited black, partially black, brown, partially brown, or yellowish-white pigmentation in the seed coat. Antioxidant activity and contents of anthocyanins, flavan-3-ols, and isoflavones were evaluated in the seed coat and cotyledons. The lines with black or brown seeds showed the highest antioxidant activities. The cotyledons showed no significant differences in seed coat components or antioxidant activities among lines. Black and brown seed coat components showed the highest antioxidant activities. The black seed coat contained five anthocyanins, whereas seed coats of brown- and yellow-seeded lines entirely lacked anthocyanins. Both black and brown seeds were rich in flavan-3-ols, including catechin and epicatechin, which were the predominant antioxidant contributors in brown seeds. Isoflavone contents showed weaker correlations with antioxidant activity than anthocyanins and flavan-3-ols. These results demonstrated that antioxidant activities were determined by anthocyanins in black seeds and flavan-3-ols in brown and black seeds, whereas relatively low antioxidant activities in yellow seeds reflected their high isoflavone contents. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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21 pages, 732 KiB

Open AccessArticle

A Comparative Investigation on Phenolic Composition, Characterization and Antioxidant Potentials of Five Different Australian Grown Pear Varieties

by Zening Wang, Colin J. Barrow, Frank R. Dunshea and Hafiz A. R. Suleria

Antioxidants 2021, 10(2), 151; https://doi.org/10.3390/antiox10020151 - 20 Jan 2021

Cited by 37 | Viewed by 4224

Abstract

Pear (Pyrus communis L.) is widely spread throughout the temperate regions of the world, such as China, America and Australia. This fruit is popular among consumers due to its excellent taste and perceived health benefits. Various bioactive compounds, which contribute to these [...] Read more.

Pear (Pyrus communis L.) is widely spread throughout the temperate regions of the world, such as China, America and Australia. This fruit is popular among consumers due to its excellent taste and perceived health benefits. Various bioactive compounds, which contribute to these health benefits, have been detected in the pear fruits, including a range of phenolic compounds. Five Australian grown pear varieties, which include Packham’s Triumph, Josephine de Malines, Beurre Bosc, Winter Nelis and Rico were selected for this study to examine the phenolic compounds in pears. Beurre Bosc exhibited the highest total polyphenol content (TPC) (3.14 ± 0.02 mg GAE/g), total tannin content (TTC) (1.43 ± 0.04 mg CE/g) and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) (5.72 ± 0.11 mg AAE/g), while the Josephine de Malines variety was high in total flavonoid content (TFC) (1.53 ± 0.09 mg QE/g), ferric reducing antioxidant power (FRAP) (4.37 ± 0.04 mg AAE/g), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (4.44 ± 0.01 mg AAE/g) and total antioxidant capacity (TAC) (5.29 ± 0.09 mg AAE/g). The liquid chromatography coupled with electrospray-ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS) data indicate that a total of 73 phenolic compounds were detected in Beurre Bosc (37 compounds), Josephine de Malines (34), Rico (22), Packham’s Triumph (15) and Winter Nelis (9), respectively. From HPLC-PDA quantification, the Beurre Bosc pear variety showed significantly higher in phenolic acids (chlorogenic acid; 17.58 ± 0.88 mg/g) and while flavonoids were significantly higher in Josephine de Malines (catechin; 17.45 ± 1.39 mg/g), as compared to other pear varieties. The analyses suggest that the Australian grown pears might contain an ideal source of phenolic compounds which benefit human health. The information provided by the present work can serve as practical supporting data for the use of pears in the nutraceutical, pharmaceutical and food industries. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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15 pages, 661 KiB

Open AccessArticle

Phenolic Profiles, Antioxidant Activity and Phenotypic Characterization of Lonicera caerulea L. Berries, Cultivated in Lithuania

by Lina Raudonė, Mindaugas Liaudanskas, Gabrielė Vilkickytė, Darius Kviklys, Vaidotas Žvikas, Jonas Viškelis and Pranas Viškelis

Antioxidants 2021, 10(1), 115; https://doi.org/10.3390/antiox10010115 - 15 Jan 2021

Cited by 31 | Viewed by 3448

Abstract

Lonicera caerulea L. is an early fruit-bearing plant that originates from harsh environments. Raw materials contain a body of different phenolic origin compounds that determine the multidirectional antioxidant and pharmacological activities. The aim of this study was to comprehensively evaluate the phenolic composition, [...] Read more.

Lonicera caerulea L. is an early fruit-bearing plant that originates from harsh environments. Raw materials contain a body of different phenolic origin compounds that determine the multidirectional antioxidant and pharmacological activities. The aim of this study was to comprehensively evaluate the phenolic composition, antioxidant capacities, vegetative, pomological, and sensory properties and their interrelations of selected L. caerulea cultivars, namely ‘Amphora’, ‘Wojtek’, ‘Iga’, ’Leningradskij Velikan’, ‘Nimfa’, ‘Indigo Gem’, ‘Tundra’, ‘Tola’, and fruit powders. Combined chromatographic systems were applied for the qualitative and quantitative profiling of 23 constituents belonging to the classes of anthocyanins, flavonols, flavones, proanthocyanidins, and phenolic acids. The determined markers of phytochemical profiles were cyanidin-3-glucoside, rutin, chlorogenic, and 3,5-dicaffeoylquinic acid. Anthocyanins and the predominant compound, cyanidin-3-glucoside, were the determinants of antioxidant activity. Cultivars ‘Amphora’, ‘Indigo Gem’, and ‘Tundra’ contained the greatest total amounts of identified phenolic compounds. Phenotypic characterization revealed the superiority of cultivars ‘Wojtek’ and ’Tundra’ compared to other cultivars, although ’Wojtek’ had low phenolic content and antioxidant activity and ’Tundra’ got lower sensory evaluation scores. Coupling the results of phenotypic and phytochemical characterization, cultivar ‘Tundra’ could be suitable for commercial plantations. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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17 pages, 1921 KiB

Open AccessArticle

Phenolic Profile and Bioactive Potential of Stems and Seed Kernels of Sweet Cherry Fruit

by Sílvia Afonso, Ivo Vaz Oliveira, Anne S. Meyer, Alfredo Aires, Maria José Saavedra and Berta Gonçalves

Antioxidants 2020, 9(12), 1295; https://doi.org/10.3390/antiox9121295 - 17 Dec 2020

Cited by 38 | Viewed by 6567

Abstract

Every year, large quantities of stems and pits are generated during sweet cherry processing, without any substantial use. Although stems are widely recognized by traditional medicine, detailed and feasible information about their bioactive composition or biological value is still scarce, as well as [...] Read more.

Every year, large quantities of stems and pits are generated during sweet cherry processing, without any substantial use. Although stems are widely recognized by traditional medicine, detailed and feasible information about their bioactive composition or biological value is still scarce, as well as the characterization of kernels. Therefore, we conducted a study in which bioactivity potential of extracts from stems and kernels of four sweet cherry cultivars (Early Bigi (grown under net cover (C) and without net cover (NC)), Burlat, Lapins, and Van) were examined. The assays included antioxidant (by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic) acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene-linoleic acid bleaching assays), and antibacterial activities against important Gram negative and Gram positive bacterial human isolates. Profile and individual phenolic composition of each extract were determined by High-performance liquid chromatography (HPLC) analysis. Extracts from stems of cv. Lapins and kernels of Early Bigi NC presented high levels of total phenolics, flavonoids, ortho-diphenols and saponins. Excepting for cv. Early Bigi NC, major phenolic compounds identified in stems and kernels were sakuranetin and catechin, respectively. In cv. Early Bigi NC the most abundant compounds were ellagic acid for stems and protocatechuic acid for kernels. In all extracts, antioxidant activities showed a positive correlation with the increments in phenolic compounds. Antimicrobial activity assays showed that only stem’s extracts were capable of inhibiting the growth of Gram positive isolates. This new data is intended to provide new possibilities of valorization of these by-products and their valuable properties. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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19 pages, 681 KiB

Open AccessArticle

Influence of Accelerated Solvent Extraction Conditions on the LC-ESI-MS/MS Polyphenolic Profile, Triterpenoid Content, and Antioxidant and Anti-lipoxygenase Activity of Rhododendron luteum Sweet Leaves

by Marta Olech, Lena Łyko and Renata Nowak

Antioxidants 2020, 9(9), 822; https://doi.org/10.3390/antiox9090822 - 03 Sep 2020

Cited by 21 | Viewed by 3988

Abstract

Evaluation of native plant resources and their efficient use is one of the current trends in phytochemistry. The main aim of the present study was to investigate the biological activities of different Rhododendron luteum Sweet leaf extracts obtained with the use of accelerated [...] Read more.

Evaluation of native plant resources and their efficient use is one of the current trends in phytochemistry. The main aim of the present study was to investigate the biological activities of different Rhododendron luteum Sweet leaf extracts obtained with the use of accelerated solvent extraction using different solvents and extraction temperatures. All extracts were subjected to bioactivity assays, which revealed considerable anti-lipoxygenase (23.07–90.13% lipoxygenase inhibition) and antiradical potential. All samples exhibited high 2,2-diphenyl-1-picrylhydrazyl (DPPH^•) (234.18–621.90 mg Trolox equivalents (TE)/g) and 2,2

^{'}

-azino-bis-3(ethylbenzthiazoline-6-sulphonic acid) (ABTS^•+) (88.79–349.41 mg TE/g) scavenging activity, high antioxidant potential in the Oxygen Radical Absorbance Capacity (ORAC) assay (495.77–1011.59 mg TE/g), and moderate ion chelating (Fe2+) capacity. The chemical profile of each sample was determined using liquid chromatography/electrospray ionization triple quadrupole mass spectrometry (LC-ESI-MS/MS) and spectrophotometric procedures. Twenty-three compounds representing seven polyphenol subclasses were detected and quantified, including some phenolic acids and flavonoids that had not been previously reported for this plant material. It was shown that 5-O-caffeoylquinic acid, protocatechuic acid, catechin, quercetin and its glycosides (hyperoside, isoquercetin, quercitrin), and pentacyclic triterpenes were the dominant secondary metabolites in R. luteum leaves. The antioxidant activity was found to be strongly related to different polyphenol groups and total triterpene content, while the anti-lipoxygenase potential was highly dependent on catechin. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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17 pages, 2008 KiB

Open AccessArticle

Effects of Microwave-Assisted Extraction Conditions on Antioxidant Capacity of Sweet Tea (Lithocarpus polystachyus Rehd.)

by Ao Shang, Min Luo, Ren-You Gan, Xiao-Yu Xu, Yu Xia, Huan Guo, Yi Liu and Hua-Bin Li

Antioxidants 2020, 9(8), 678; https://doi.org/10.3390/antiox9080678 - 29 Jul 2020

Cited by 27 | Viewed by 3212

Abstract

In this study, the effects of microwave-assisted extraction conditions on antioxidant capacity of sweet tea (Lithocarpus polystachyus Rehd.) were studied and the antioxidants in the extract were identified. The influences of ethanol concentration, solvent-to-sample ratio, microwave power, extraction temperature and extraction time [...] Read more.

In this study, the effects of microwave-assisted extraction conditions on antioxidant capacity of sweet tea (Lithocarpus polystachyus Rehd.) were studied and the antioxidants in the extract were identified. The influences of ethanol concentration, solvent-to-sample ratio, microwave power, extraction temperature and extraction time on Trolox equivalent antioxidant capacity (TEAC) value, ferric reducing antioxidant power (FRAP) value and total phenolic content (TPC) were investigated by single-factor experiments. The response surface methodology (RSM) was used to study the interaction of three parameters which had significant influences on antioxidant capacity including ethanol concentration, solvent-to-sample ratio and extraction time. The optimal conditions for the extraction of antioxidants from sweet tea were found as follows—ethanol concentration of 58.43% (v/v), solvent-to-sample ratio of 35.39:1 mL/g, extraction time of 25.26 min, extraction temperature of 50 ℃ and microwave power of 600 W. The FRAP, TEAC and TPC values of the extract under the optimal conditions were 381.29 ± 4.42 μM Fe(II)/g dry weight (DW), 613.11 ± 9.32 μM Trolox/g DW and 135.94 ± 0.52 mg gallic acid equivalent (GAE)/g DW, respectively. In addition, the major antioxidant components in the extract were detected by high-performance liquid chromatography with diode array detection (HPLC-DAD), including phlorizin, phloretin and trilobatin. The crude extract could be used as food additives or developed into functional food for the prevention and management of oxidative stress-related diseases. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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24 pages, 2576 KiB

Open AccessArticle

Enrichment in Antioxidant Flavonoids of Stamen Extracts from Nymphaea lotus L. Using Ultrasonic-Assisted Extraction and Macroporous Resin Adsorption

by Duangjai Tungmunnithum, Samantha Drouet, Atul Kabra and Christophe Hano

Antioxidants 2020, 9(7), 576; https://doi.org/10.3390/antiox9070576 - 02 Jul 2020

Cited by 40 | Viewed by 4513

Abstract

Nymphaea lotus L. is the medicinal plant that has long been used for food, cosmetics and traditional medicines in Africa and Asia since ancient times. Its flavonoids and other interesting phytochemical compounds from rhizome, leaf and the whole flowers have been reported in [...] Read more.

Nymphaea lotus L. is the medicinal plant that has long been used for food, cosmetics and traditional medicines in Africa and Asia since ancient times. Its flavonoids and other interesting phytochemical compounds from rhizome, leaf and the whole flowers have been reported in the previous published research. However, stamens, which are essential for reproductive functions, may also represent new alternative sources of potential antioxidant flavonoids, as investigated in this study. The innovative green chemistry methods, i.e., ultrasound-assisted extraction (UAE) as well as a macroporous resin (MPR) purification procedure, were employed in this current research. Using a full factorial design coupled to three-dimensional (3D) surface plot methodology, the influence of three variables, namely aqEtOH concentration (ranging from 50 to 100% (v/v), US frequency (ranging from 0 (no US applied) to 45 kHz), and the extraction duration (ranging from 20 to 60 min), were evaluated. Five MPRs with different surface areas, average pore diameters, matrix types and polarities were also investigated for the purification of total flavonoids. The optimal UAE condition is 90% (v/v) aqEtOH with 34.65 khz ultrasonic frequency and 46 min of extraction duration. Compared with the conventional heat reflux extraction (HRE) method, a significant 1.35-fold increase in total flavonoids content was obtained using optimized UAE conditions (169.64 for HRE vs. 235.45 mg/g dry weight for UAE), causing a 2.80-fold increase when this UAE associated with MPR purification (475.42 mg/g dry weight). In vitro cell free antioxidant activity of N. lotus stamen extracts and in cellulo antioxidant investigation using yeast model showed the same trend, indicating that the best antioxidant flavonoid can be found in UAE coupled with MPR purification. Moreover, in the yeast model, the expression of key antioxidant genes such as SIR2 and SOD2 were expressed at the highest level in yeast cells treated with the extract from UAE together with MPR purification. Consequently, it can be seen that the UAE combined with MPR purification can help enhance the flavonoid antioxidant potential of the stamens extract from this medicinal species. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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12 pages, 529 KiB

Open AccessArticle

Antioxidant Activity Modulated by Polyphenol Contents in Apple and Leaves during Fruit Development and Ripening

by Aneta Wojdyło and Jan Oszmiański

Antioxidants 2020, 9(7), 567; https://doi.org/10.3390/antiox9070567 - 01 Jul 2020

Cited by 50 | Viewed by 4282

Abstract

Apples (Malus domestica Borkh) are of particular interest for their high content of healthy phytochemicals. This study investigated the antioxidant activity and polyphenolic compounds of extracts from the fruits from Ozark Gold, Starkinson and Kosztela cultivars and additionally leaves from Ozark Gold [...] Read more.

Apples (Malus domestica Borkh) are of particular interest for their high content of healthy phytochemicals. This study investigated the antioxidant activity and polyphenolic compounds of extracts from the fruits from Ozark Gold, Starkinson and Kosztela cultivars and additionally leaves from Ozark Gold cv. Phenolic compounds were identified and quantified by liquid chromatography- mass spectrometer (LC–MS) and high pressure liquid chromatography (HPLC). The samples were collected during fruit development at 60, 80, 130 and 145 days after full bloom. The concentration of apple phenolics was highest early in the season and decreased during fruit development. The leaf phenolics had a more steady level during all the period of collection than the fruits. Among the five groups of analyzed polyphenols, the procyanidins predominated in apple fruits and dihydrochalcones in leaves. The concentration of polyphenols decreased from 39.15, 5.97 and 33.39 g/kg dw (collected at 60 days after full bloom) to 14.22, 2.05 and 9.31 g/kg dw (collected at 145 days after full bloom) for apples Ozark Gold, Starkinson, Kosztela, respectively. The leaves characterized a much higher content of polyphenolic compounds and antioxidant capacity than unripe fruits. Antioxidant capacity measured by 2,2-azinobis-(3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-picrylhydrazyl (DPPH) methods was higher when the apple was unripe and the leaves were young. The results indicate that, unripe fruits and leaves are very good raw material for polyphenol nutraceutical production with high antioxidant potential. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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14 pages, 687 KiB

Open AccessArticle

Qualitative Aspects of Some Traditional Landraces of the Tomato “Piennolo” (Solanum lycopersicum L.) of the Campania Region, Southern Italy

by Florinda Fratianni, Autilia Cozzolino, Antonio d’Acierno, Filomena Nazzaro, Riccardo Riccardi and Patrizia Spigno

Antioxidants 2020, 9(7), 565; https://doi.org/10.3390/antiox9070565 - 28 Jun 2020

Cited by 17 | Viewed by 2758

Abstract

Our study aimed to analyze some qualitative aspects of five landraces of the tomato “Piennolo,” typical of the Vesuvian area, Italy, and determine the in vitro antioxidant activity. All samples showed a high °Brix value and acidity, as well as a discrete amount [...] Read more.

Our study aimed to analyze some qualitative aspects of five landraces of the tomato “Piennolo,” typical of the Vesuvian area, Italy, and determine the in vitro antioxidant activity. All samples showed a high °Brix value and acidity, as well as a discrete amount of reducing sugars, indicating their good quality as fresh products. They showed a high content of lycopene (up to 218 μg g⁻¹ of fresh product) and ascorbic acid (up to 238 μg g⁻¹ of fresh product). The content of total polyphenols was never less than 278 μg g⁻¹ of fresh product. Hyperoside, chlorogenic and gallic acids were the most abundant polyphenols. The interrelationships between the parameters analyzed and the different landraces showed that total polyphenols could have mostly affected (ρ = 0.76) the antioxidant activity more than lycopene (ρ = −0.96). The interrelationships between the most abundant polyphenols and antioxidant activity showed that hyperoside, although the most abundant, negatively affected (ρ = −0.93) the antioxidant activity. Due to the high content of lycopene, ascorbic acid, and hyperoside, the five landraces of the tomato “Piennolo” could be considered promising in terms of their potential healthy characteristics. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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17 pages, 2558 KiB

Open AccessArticle

Coreolanceolins A–E, New Flavanones from the Flowers of Coreopsis lanceolate, and Their Antioxidant and Anti-Inflammatory Effects

by Hyoung-Geun Kim, Young Sung Jung, Seon Min Oh, Hyun-Ji Oh, Jung-Hwan Ko, Dae-Ok Kim, Se Chan Kang, Yeong-Geun Lee, Dae Young Lee and Nam-In Baek

Antioxidants 2020, 9(6), 539; https://doi.org/10.3390/antiox9060539 - 19 Jun 2020

Cited by 14 | Viewed by 3491

Abstract

(1) Background: Many flavonoids derived from natural sources have been reported to exhibit antioxidant and anti-inflammatory effects. Our preliminary study suggested that Coreopsis lanceolata flowers (CLFs) include high flavonoid content; (2) Methods: CLFs were extracted in 80% (v/v) aqueous methanol and fractionated into [...] Read more.

(1) Background: Many flavonoids derived from natural sources have been reported to exhibit antioxidant and anti-inflammatory effects. Our preliminary study suggested that Coreopsis lanceolata flowers (CLFs) include high flavonoid content; (2) Methods: CLFs were extracted in 80% (v/v) aqueous methanol and fractionated into ethyl acetate, n-butanol, and water fractions. Repeated column chromatographies for the organic fractions led to the isolation of seven flavanones. Quantitative analysis of the flavanones was carried out using reversed-phase high-performance liquid chromatography. All flavanones were evaluated for their antioxidant and pro-inflammatory inhibition effects; (3) Results: Spectroscopic analyses revealed the chemical structure of five new flavanones, coreolanceolins A–E, and two known ones. The content of the seven flavanones in extracts were determined from 0.8 ± 0.1 to 38.8 ± 0.3 mg/g. All flavanones showed radical scavenging activities (respectively 104.3 ± 1.9 to 20.5 ± 0.3 mg vitamin C equivalents (VCE)/100 mg and 1278.6 ± 26.8 to 325.6 ± 0.2 mg VCE/100 mg) in the DPPH and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays and recovery activities in Caco-2 (59.7 to 41.1%), RAW264.7 (87.8 to 56.0%), and PC-12 (100.5 to 69.9%) cells against reactive oxygen species. Furthermore, all flavanones suppressed nitric oxide production (99.5% to 37.3%) and reduced iNOS and COX-2 expression in lipopolysaccharide-treated RAW 264.7 cells; (4) Conclusions: Five new and two known flavanones were isolated from CLF, and most of them showed high antioxidant and pro-inflammatory inhibition effects. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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12 pages, 758 KiB

Open AccessArticle

Phenolic Acid Profiles and Antioxidant Activity of Major Cereal Crops

by Daniela Horvat, Gordana Šimić, Georg Drezner, Alojzije Lalić, Tatjana Ledenčan, Marijana Tucak, Hrvoje Plavšić, Luka Andrić and Zvonimir Zdunić

Antioxidants 2020, 9(6), 527; https://doi.org/10.3390/antiox9060527 - 16 Jun 2020

Cited by 55 | Viewed by 4703

Abstract

Phenolic acids (PAs) are a dominant group of phenolic compounds in cereals, existing mostly bound to compounds of cell wall. In this study, a total of 25 cereal grain samples, including wheat, winter and spring barley, corn, and popcorn, were evaluated for bound [...] Read more.

Phenolic acids (PAs) are a dominant group of phenolic compounds in cereals, existing mostly bound to compounds of cell wall. In this study, a total of 25 cereal grain samples, including wheat, winter and spring barley, corn, and popcorn, were evaluated for bound PAs and antioxidant activity in a two-year field trial. The PA contents, determined by HPLC, were significantly affected by cereal type. The mean total PA content was highest in popcorn and corn (3298 and 2213 μg/g_dm, respectively₎, followed by winter and spring barley (991 and 908 μg/g_dm, respectively) and wheat (604 μg/g_dm). Ferulic acid was the most abundant, accounting from 62% to 83% of total PAs (in popcorn and winter and spring barley, respectively). Across cereals, p-coumaric (35–259 μg/g_dm) and p-hidroxybenzoic (45–79 μg/g_dm) were also dominant, while in corn and popcorn o-coumaric (71 and 89 μg/g_dm, respectively) also occurred in higher content. The mean total phenol content ranged from 853 μg GAE/g_dm (wheat) to 1403 μg GAE/g_dm (winter barley) with DPPH scavenging activity from 14% to 67%, respectively. A significant influence of crop years on the ferulic acid and total PA content was found, while the variability of other PAs was dependent on the cereal type. The results indicated a high health benefit potential of selected cereals. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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29 pages, 1564 KiB

Open AccessArticle

LC-MS Profile, Gastrointestinal and Gut Microbiota Stability and Antioxidant Activity of Rhodiola rosea Herb Metabolites: A Comparative Study with Subterranean Organs

by Daniil N. Olennikov, Nadezhda K. Chirikova, Aina G. Vasilieva and Innokentii A. Fedorov

Antioxidants 2020, 9(6), 526; https://doi.org/10.3390/antiox9060526 - 16 Jun 2020

Cited by 41 | Viewed by 4397

Abstract

Golden root (Rhodiola rosea L., Crassulaceae) is a famous medical plant with a one-sided history of scientific interest in the roots and rhizomes as sources of bioactive compounds, unlike the herb, which has not been studied extensively. To address this deficiency, we [...] Read more.

Golden root (Rhodiola rosea L., Crassulaceae) is a famous medical plant with a one-sided history of scientific interest in the roots and rhizomes as sources of bioactive compounds, unlike the herb, which has not been studied extensively. To address this deficiency, we used high-performance liquid chromatography with diode array and electrospray triple quadrupole mass detection for comparative qualitative and quantitative analysis of the metabolic profiles of Rhodiola rosea organs before and after gastrointestinal digestion in simulated conditions together with various biochemical assays to determine antioxidant properties of the extracts and selected compounds. R. rosea organs showed 146 compounds, including galloyl O-glucosides, catechins, procyanidins, simple phenolics, phenethyl alcohol derivatives, (hydroxy)cinnamates, hydroxynitrile glucosides, monoterpene O-glucosides, and flavonol O-glycosides, most of them for the first time in the species. The organ-specific distribution of compounds found for catechins, procyanidins, and cinnamyl alcohols and glucosides was typical for underground organs and flavonoids and galloylated glucoses concentrated in the herb. Extracts from rhizomes, leaves and flowers showed high phenolic content and were effective scavengers of free radicals (2,2-diphenyl-1-picrylhydrazyl (DPPH^•), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•+), O₂^•−, ^•OH) and protected β-carotene in a bleaching assay. Digestion in the gastric and intestine phase influenced the composition of R. rosea extracts negatively, affecting the content of catechins, procyanidins, and galloyl glucoses, and therefore, the antioxidativity level. After gut microbiota treatment, the antioxidant capacity of rhizome extract was lower than leaves and flowers due to the aglycone composition found in the colonic phase of digestion. Our study demonstrated that the herb of R. rosea is a rich source of metabolites with high antioxidant properties and could be a valuable plant for new bioactive products. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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19 pages, 829 KiB

Open AccessArticle

Superior Antioxidant Capacity of Berberis iliensis—HPLC-Q-TOF-MS Based Phytochemical Studies and Spectrophotometric Determinations

by Saniia Abdykerimova, Zuriyadda Sakipova, Sylwia Nakonieczna, Wojciech Koch, Anna Biernasiuk, Aneta Grabarska, Anna Malm, Kaldanay Kozhanova and Wirginia Kukula-Koch

Antioxidants 2020, 9(6), 504; https://doi.org/10.3390/antiox9060504 - 09 Jun 2020

Cited by 18 | Viewed by 3566

Abstract

The aim of the present study was to determine the composition, antiradical and antimicrobial activity of fruits, leaves and roots of an underestimated species of barberry—Berberis iliensis—growing in Kazakhstan. Particular attention was paid to the determination of the composition of its [...] Read more.

The aim of the present study was to determine the composition, antiradical and antimicrobial activity of fruits, leaves and roots of an underestimated species of barberry—Berberis iliensis—growing in Kazakhstan. Particular attention was paid to the determination of the composition of its extracts by high-performance liquid chromatography coupled with mass spectrometry (HPLC-ESI-Q-TOF-MS) analysis. As a result of the chromatographic and spectrometric study 33 secondary metabolites from the groups of phenolic acids and their esters, flavonoids, alkaloids and organic acids were identified and 15 of them—quantified. The isomers of caffeoyl-glucaric acid, caffeic acid derivatives, isoquercetin, berberine and jatrorrhizine were the most abundant components of the tested extracts. The antiradical activity tests were performed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Folin-Ciocalteu assays on four types of extracts (water, ethanol, ethanol-water 7:3 v/v, ethanol-water 1:1 v/v) from the three organs of the plant. The highest antiradical potential (IC50 = 80 ± 6.36 µg/mL) and phenolic content (440 ± 17.1 mg gallic acid equivalents/L) was calculated for ethanol- water (1:1 v/v) extracts from the leaves and could be influenced by the abundant presence of simple phenolic acids, flavonoids and glucaric acid esters. Among reference microorganisms, M. luteus, S. epidermidis, some S. aureus and B. cereus belonging to Gram-positive bacteria and yeasts from Candida species were the most sensitive to roots extract that was found the most active among the studied samples. The results of the study classify Berberis iliensis as a strong antioxidant agent and as a plant with an antimicrobial potential. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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14 pages, 1424 KiB

Open AccessArticle

Screening of Natural Stilbene Oligomers from Vitis vinifera for Anticancer Activity on Human Hepatocellular Carcinoma Cells

by Iris Aja, M. Begoña Ruiz-Larrea, Arnaud Courtois, Stéphanie Krisa, Tristan Richard and José-Ignacio Ruiz-Sanz

Antioxidants 2020, 9(6), 469; https://doi.org/10.3390/antiox9060469 - 01 Jun 2020

Cited by 21 | Viewed by 2916

Abstract

The characterization of bioactive resveratrol oligomers extracted from Vitis vinifera canes has been recently reported. Here, we screened six of these compounds (ampelopsin A, trans-ε-viniferin, hopeaphenol, isohopeaphenol, R2-viniferin, and R-viniferin) for their cytotoxic activity to human hepatocellular carcinoma (HCC) cell lines p53 [...] Read more.

The characterization of bioactive resveratrol oligomers extracted from Vitis vinifera canes has been recently reported. Here, we screened six of these compounds (ampelopsin A, trans-ε-viniferin, hopeaphenol, isohopeaphenol, R2-viniferin, and R-viniferin) for their cytotoxic activity to human hepatocellular carcinoma (HCC) cell lines p53 wild-type HepG2 and p53-null Hep3B. The cytotoxic efficacy depended on the cell line. R2-viniferin was the most toxic stilbene in HepG2, with inhibitory concentration 50 (IC₅₀) of 9.7 ± 0.4 µM at 72 h, 3-fold lower than for resveratrol, while Hep3B was less sensitive (IC₅₀ of 47.8 ± 2.8 µM). By contrast, hopeaphenol (IC₅₀ of 13.1 ± 4.1 µM) and isohopeaphenol (IC₅₀ of 26.0 ± 3.0 µM) were more toxic to Hep3B. Due to these results, and because it did not exert a large cytotoxicity in HH4 non-transformed hepatocytes, R2-viniferin was selected to investigate its mechanism of action in HepG2. The stilbene tended to arrest cell cycle at G2/M, and it also increased intracellular reactive oxygen species (ROS), caspase 3 activity, and the ratio of Bax/Bcl-2 proteins, indicative of apoptosis. The distinctive toxicity of R2-viniferin on HepG2 encourages research into the underlying mechanism to develop the oligostilbene as a therapeutic agent against HCC with a particular genetic background. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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26 pages, 3944 KiB

Open AccessReview

An Overview of the Genus Cotoneaster (Rosaceae): Phytochemistry, Biological Activity, and Toxicology

by Agnieszka Kicel

Antioxidants 2020, 9(10), 1002; https://doi.org/10.3390/antiox9101002 - 16 Oct 2020

Cited by 9 | Viewed by 6558

Abstract

Traditional herbal medicines have become a subject of global importance with both medical and economic implications. The regular consumption of herbal drugs has led to serious concerns regarding their quality, effectiveness, and safety. Thus, relevant scientific evidence has become an important criterion for [...] Read more.

Traditional herbal medicines have become a subject of global importance with both medical and economic implications. The regular consumption of herbal drugs has led to serious concerns regarding their quality, effectiveness, and safety. Thus, relevant scientific evidence has become an important criterion for the acceptance of traditional health claims. The genus Cotoneaster Medikus provides numerous species traditionally used in Asian medicine for the treatment of haemorrhoids, diabetes, and cardiovascular diseases. This review summarises the achievements of modern research on the Cotoneaster taxa, including ethnobotany, phytochemistry, pharmacology, and toxicology. To date, more than 90 compounds have been isolated or analytically identified in Cotoneaster leaves, fruits, flowers or twigs. These phytochemicals are categorised into flavonoids, procyanidins, phenolic acids, cotonefurans, cyanogenic glycosides, triterpenes, sterols, fatty acids, volatile compounds, and carbohydrates, and many of them are responsible for Cotoneaster pharmacological properties including antioxidant, anti-inflammatory, antimicrobial, antiparasitic, hepatoprotective, anti-diabetic or anti-dyslipidaemic activity. In order to ensure the safety of pharmaceutical applications, the potential toxicity of Cotoneaster extracts has also been investigated. In conclusion, this systematic review provides an important reference base for further study into the various medical applications of both the dry extracts and pure isolates of Cotoneaster species. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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22 pages, 980 KiB

Open AccessReview

Polyphenols as Possible Agents for Pancreatic Diseases

by Uroš Gašić, Ivanka Ćirić, Tomislav Pejčić, Dejan Radenković, Vladimir Djordjević, Siniša Radulović and Živoslav Tešić

Antioxidants 2020, 9(6), 547; https://doi.org/10.3390/antiox9060547 - 23 Jun 2020

Cited by 15 | Viewed by 4988

Abstract

Pancreatic cancer (PC) is very aggressive and it is estimated that it kills nearly 50% of patients within the first six months. The lack of symptoms specific to this disease prevents early diagnosis and treatment. Today, gemcitabine alone or in combination with other [...] Read more.

Pancreatic cancer (PC) is very aggressive and it is estimated that it kills nearly 50% of patients within the first six months. The lack of symptoms specific to this disease prevents early diagnosis and treatment. Today, gemcitabine alone or in combination with other cytostatic agents such as cisplatin (Cis), 5-fluorouracil (5-FU), irinotecan, capecitabine, or oxaliplatin (Oxa) is used in conventional therapy. Outgoing literature provides data on the use of polyphenols, biologically active compounds, in the treatment of pancreatic cancer and the prevention of acute pancreatitis. Therefore, the first part of this review gives a brief overview of the state of pancreatic disease as well as the procedures for its treatment. The second part provides a detailed overview of the research regarding the anticancer effects of both pure polyphenols and their plant extracts. The results regarding the antiproliferative, antimetastatic, as well as inhibitory effects of polyphenols against PC cell lines as well as the prevention of acute pancreatitis are presented in detail. Finally, particular emphasis is given to the polyphenolic profiles of apples, berries, cherries, sour cherries, and grapes, given the fact that these fruits are rich in polyphenols and anthocyanins. Polyphenolic profiles, the content of individual polyphenols, and their relationships are discussed. Based on this, significant data can be obtained regarding the amount of fruit that should be consumed daily to achieve a therapeutic effect. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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33 pages, 4601 KiB

Open AccessReview

A Reference List of Phenolic Compounds (Including Stilbenes) in Grapevine (Vitis vinifera L.) Roots, Woods, Canes, Stems, and Leaves

by Piebiep Goufo, Rupesh Kumar Singh and Isabel Cortez

Antioxidants 2020, 9(5), 398; https://doi.org/10.3390/antiox9050398 - 08 May 2020

Cited by 122 | Viewed by 7726

Abstract

Due to their biological activities, both in plants and in humans, there is a great interest in finding natural sources of phenolic compounds or ways to artificially manipulate their levels. During the last decade, a significant amount of these compounds has been reported [...] Read more.

Due to their biological activities, both in plants and in humans, there is a great interest in finding natural sources of phenolic compounds or ways to artificially manipulate their levels. During the last decade, a significant amount of these compounds has been reported in the vegetative organs of the vine plant. In the roots, woods, canes, stems, and leaves, at least 183 phenolic compounds have been identified, including 78 stilbenes (23 monomers, 30 dimers, 8 trimers, 16 tetramers, and 1 hexamer), 15 hydroxycinnamic acids, 9 hydroxybenzoic acids, 17 flavan-3-ols (of which 9 are proanthocyanidins), 14 anthocyanins, 8 flavanones, 35 flavonols, 2 flavones, and 5 coumarins. There is great variability in the distribution of these chemicals along the vine plant, with leaves and stems/canes having flavonols (83.43% of total phenolic levels) and flavan-3-ols (61.63%) as their main compounds, respectively. In light of the pattern described from the same organs, quercetin-3-O-glucuronide, quercetin-3-O-galactoside, quercetin-3-O-glucoside, and caftaric acid are the main flavonols and hydroxycinnamic acids in the leaves; the most commonly represented flavan-3-ols and flavonols in the stems and canes are catechin, epicatechin, procyanidin B1, and quercetin-3-O-galactoside. The main stilbenes (trans-ε-viniferin, trans-resveratrol, isohopeaphenol/hopeaphenol, vitisin B, and ampelopsins) accumulate primarily in the woods, followed by the roots, the canes, and the stems, whereas the leaves, which are more exposed to environmental stresses, have a low concentration of these compounds. Data provided in this review could be used as (i) a metabolomic tool for screening in targeted and untargeted analyses and (ii) a reference list in studies aimed at finding ways to induce naturally occurring polyphenols on an industrial scale for pant and human disease control. Full article

(This article belongs to the Special Issue Phenolics as Antioxidant Agents)

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