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25 pages, 3552 KiB

Open AccessArticle

Assessing the Efficiency of Antimicrobial Plant Extracts from Artemisia afra and Eucalyptus globulus as Coatings for Textiles

by Elvino Nortjie, Moses Basitere, Doice Moyo and Pardon Nyamukamba

Plants 2024, 13(4), 514; https://doi.org/10.3390/plants13040514 - 13 Feb 2024

Viewed by 895

Abstract

This study aimed to assess the antimicrobial activities of plant extracts from Artemisia afra and Eucalyptus globulus when used as coatings for textiles. A pulsed ultrasound-assisted extraction method (PUAE) was employed to obtain methanolic and hexanoic extracts from both plants. Eucalyptus globulus methanol [...] Read more.

This study aimed to assess the antimicrobial activities of plant extracts from Artemisia afra and Eucalyptus globulus when used as coatings for textiles. A pulsed ultrasound-assisted extraction method (PUAE) was employed to obtain methanolic and hexanoic extracts from both plants. Eucalyptus globulus methanol extraction exhibited the highest yield at 22.76% (±0.61%), while Artemisia afra demonstrated lower yields. Phytochemical screening identified various secondary metabolites in the extracts, including phenols, quinones, and steroids. Antimicrobial tests against Staphylococcus aureus and Escherichia coli revealed varying degrees of susceptibility, with Eucalyptus globulus hexanoic extracts showing the highest activity against Staphylococcus aureus at an average percentage growth of 18.74% (±0.26%). Minimum inhibitory concentration (MIC) values were determined for the extracts, but complete inhibition did not occur at concentrations below 500 μg/mL. The extracts exhibited varying effects on Staphylococcus aureus and Escherichia coli growth, with some extracts promoting bacterial growth. Coating textiles with Eucalyptus globulus methanolic extracts demonstrated antibacterial activity against Staphylococcus aureus with the highest zone of inhibition observed in cotton-coated samples (258.4 mm²). Polyester-coated samples exhibited smaller inhibition zones, with the lowest observed in Eucalyptus globulus methanolic extract coating (65.97 mm²). Scanning electron microscope (SEM) analysis revealed visible surface morphology changes in coated fabrics, depicting fine, cluster, lumpy, flaky, and fragment-like morphologies. Laundering effects on coated fabrics were investigated, showing a significant decrease in antimicrobial activity after washing. Fourier-transform infrared spectroscopy (FTIR) identified functional groups in the extracts associated with antimicrobial properties. The complexity of the bioactive compounds suggests potential antimicrobial efficacy, resting on factors such as geographical location, climate, and extraction methods. Notwithstanding the limitations, this study contributes valuable insights into the use of plant extracts as antimicrobial coatings for textiles. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Natural Compounds)

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15 pages, 3329 KiB

Open AccessArticle

Assessing Spectral Analysis of Phytoconstituents and Their In Silico Interactions with Target Proteins in Plant Seed Extracts

by Venkatadri Babu, J Irshad Ahamed, Agastian Paul, Sajad Ali, Irfan A. Rather and Jamal S. M. Sabir

Plants 2023, 12(19), 3352; https://doi.org/10.3390/plants12193352 - 22 Sep 2023

Viewed by 914

Abstract

The pharmacological and preventive attributes of extracts from vegetable seeds have garnered widespread recognition within the scientific community. This study systematically assessed the in vitro antibacterial, antioxidant, and anti-breast cancer properties of phytochemicals present in various solvent-based vegetable seed extracts. We also conducted [...] Read more.

The pharmacological and preventive attributes of extracts from vegetable seeds have garnered widespread recognition within the scientific community. This study systematically assessed the in vitro antibacterial, antioxidant, and anti-breast cancer properties of phytochemicals present in various solvent-based vegetable seed extracts. We also conducted molecular docking simulations to ascertain their interactions with specific target proteins. Besides, nine distinct chemical constituents were identified using gas chromatography-mass spectrometry (GCMS). Remarkably, the ethyl acetate extract exhibited robust inhibitory effects against Gram-positive and Gram-negative bacterial strains. Furthermore, its capacity for 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging was found to be noteworthy, with an IC₅₀ value of 550.82 ± 1.7 µg/mL, representing a scavenging efficiency of 64.1 ± 2.8%. Additionally, the ethyl acetate extract demonstrated significant hydrogen peroxide (H₂O₂) scavenging activity, with a maximal scavenging rate of 44.1 ± 1.70% (IC₅₀) at a concentration of 761.17 ± 1.8 µg/mL. Intriguingly, in vitro cytotoxicity assays against human breast cancer (MCF-7) cells revealed varying levels of cell viability at different extract concentrations, suggesting potential anticancer properties. Importantly, these ethyl acetate extracts did not display toxicity to L929 cells across the concentration range tested. Subsequently, we conducted in-silico molecular docking experiments utilizing Discovery Studio 4.0 against the c-Met kinase protein (hepatocyte growth factor; PDB ID: 1N0W). Among the various compounds assessed, 3,4-Dihydroxy-1,6-bis-(3-methoxy-phenyl)-hexa-2,4-diene-1,6-dione exhibited a notable binding energy of −9.1 kcal/mol, warranting further investigation into its potential anticancer properties, clinical applications, and broader pharmacological characteristics. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Natural Compounds)

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15 pages, 851 KiB

Open AccessArticle

Evaluation of Antimicrobial Activity of Kitaibelia vitifolia Extract against Proven Antibiotic-Susceptible and Multidrug-Resistant (MDR) Strains of Bacteria of Clinical Origin

by Vladimir S. Kurćubić, Svetlana V. Raketić, Jelena M. Mašković, Pavle Z. Mašković, Luka V. Kurćubić, Volker Heinz and Igor B. Tomasevic

Plants 2023, 12(18), 3236; https://doi.org/10.3390/plants12183236 - 12 Sep 2023

Viewed by 992

Abstract

The goal of the present research was to screen the antimicrobial activity of an ethanolic extract of Kitaibelia vitifolia against 30 multidrug-resistant (MDR) bacterial strains isolated from healthcare-associated infections. Minimum inhibitory concentrations (MICs) of the samples against the tested bacteria were determined using [...] Read more.

The goal of the present research was to screen the antimicrobial activity of an ethanolic extract of Kitaibelia vitifolia against 30 multidrug-resistant (MDR) bacterial strains isolated from healthcare-associated infections. Minimum inhibitory concentrations (MICs) of the samples against the tested bacteria were determined using the microdilution method. MDR bacterial strains were characterized using standard biochemical tests and the commercial identification systems API 20 NE and API 20 E as: Klebsiella spp. (18 isolates—I); methicillin-resistant Staphylococcus aureus (MRSA)—3; Acinetobacter spp.—3; Pseudomonas aeruginosa—5; vancomycin-resistant Enterococcus (VRE)—1. The sensitivity of isolated bacterial strains was determined using the disc diffusion method against 25 commonly used antibiotics. The highest level of sensitivity to K. vitifolia extract was confirmed in 88.89% of Klebsiella spp. isolates, E. coli ATCC 25922, two strains of MRSA (1726, 1063), Acinetobacter spp. strain 1578, and VRE strain 30, like Enterococcus faecalis ATCC 29212 (MIC =< 2.44 μg/mL). The lowest sensitivity was exhibited by 75.00% of Acinetobacter spp. (strains 1577 and 6401), where the highest values for MICs were noted (1250 μg/mL). The results indicate that the extract of K. vitifolia could be a possible source for creating new, efficient, and effective natural medicines for combat against MDR strains of bacteria. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Natural Compounds)

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26 pages, 10411 KiB

Open AccessArticle

Identification of Potential Phytochemical/Antimicrobial Agents against Pseudoperonospora cubensis Causing Downy Mildew in Cucumber through In-Silico Docking

by Nagaraju Jhansirani, Venkatappa Devappa, Chittarada Gopal Sangeetha, Shankarappa Sridhara, Kodegandlu Subbanna Shankarappa and Mooventhiran Mohanraj

Plants 2023, 12(11), 2202; https://doi.org/10.3390/plants12112202 - 02 Jun 2023

Viewed by 1385

Abstract

Compatibility interactions between the host and the fungal proteins are necessary to successfully establish a disease in plants by fungi or other diseases. Photochemical and antimicrobial substances are generally known to increase plant resilience, which is essential for eradicating fungus infections. Through homology [...] Read more.

Compatibility interactions between the host and the fungal proteins are necessary to successfully establish a disease in plants by fungi or other diseases. Photochemical and antimicrobial substances are generally known to increase plant resilience, which is essential for eradicating fungus infections. Through homology modeling and in silico docking analysis, we assessed 50 phytochemicals from cucumber (Cucumis sativus), 15 antimicrobial compounds from botanical sources, and six compounds from chemical sources against two proteins of Pseudoperonospora cubensis linked to cucumber downy mildew. Alpha and beta sheets made up the 3D structures of the two protein models. According to Ramachandran plot analysis, the QNE 4 effector protein model was considered high quality because it had 86.8% of its residues in the preferred region. The results of the molecular docking analysis showed that the QNE4 and cytochrome oxidase subunit 1 proteins of P. cubensis showed good binding affinities with glucosyl flavones, terpenoids and flavonoids from phytochemicals, antimicrobial compounds from botanicals (garlic and clove), and chemically synthesized compounds, indicating the potential for antifungal activity. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Natural Compounds)

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19 pages, 2902 KiB

Open AccessArticle

Antibacterial and Antibiofilm Activity of Different Species of Fabiana sp. Extract Obtained via Maceration and Ultrasound-Assisted Extraction against Staphylococcus epidermidis

by José Martínez Chamás, María Inés Isla and Iris Catiana Zampini

Plants 2023, 12(9), 1830; https://doi.org/10.3390/plants12091830 - 29 Apr 2023

Cited by 1 | Viewed by 1228

Abstract

Staphylococcus epidermidis is an opportunistic pathogen that, under certain conditions, can induce aggravated infectious processes, mainly in immunosuppressed patients. Moreover, S. epidermidis is one of the leading causes of medical device- and implant-associated infections and is also recognized as a canonical biofilm producer. [...] Read more.

Staphylococcus epidermidis is an opportunistic pathogen that, under certain conditions, can induce aggravated infectious processes, mainly in immunosuppressed patients. Moreover, S. epidermidis is one of the leading causes of medical device- and implant-associated infections and is also recognized as a canonical biofilm producer. Fabiana punensis, F. densa and F. patagonica are three medicinal plants that grow in arid environments in Argentina (Altoandina, Puna, Prepuna and Monte regions). In this work, we studied the antimicrobial activity of alcoholic extracts of these plant species obtained via maceration (M) and ultrasound-assisted extraction (UAE) against S. epidermidis. In addition, the antibiofilm activity of the F. densa extract was also evaluated. It was found that the extracts obtained via M did not present differences with those obtained via UAE regarding the chemical profile. F. densa showed the lowest minimum inhibitory concentration (MIC) value (75 µg GAE/mL). At concentrations higher than the MIC, the extract induced the release of cellular constituents. At the concentration of 1/8× MIC, the extract inhibited biofilm formation by 78%, reducing metabolic activity by 67%. On the other hand, it presented a low percentage of preformed biofilm removal. In all assays, gallic acid (GA) has been used as a reference antimicrobial compound. Finally, it was shown via microscopy visualization that the extract reduces adhesion to hydrophobic and hydrophilic surfaces. Thus, F. densa extracts could potentially be used for the antibiotic treatment of infections produced by S. epidermidis or as an inhibitor agent of production biofilm, avoiding infections caused by medical devices. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Natural Compounds)

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10 pages, 3497 KiB

Open AccessArticle

The Effect of Light and Dark Treatment on the Production of Rosmarinic Acid and Biological Activities in Perilla frutescens Microgreens

by Seom Lee, Hyeon Ji Yeo, Sang Yeob Lee, Su Ryang Kim, Sang Un Park and Chang Ha Park

Plants 2023, 12(8), 1613; https://doi.org/10.3390/plants12081613 - 10 Apr 2023

Viewed by 1210

Abstract

This study aimed to investigate the effect of light [a long-day photoperiod (16 h light/8 h dark cycle)] and dark treatment on the production of rosmarinic acid in P. frutescens microgreens and to determine its antioxidant and antibacterial activities. Microgreens of P [...] Read more.

This study aimed to investigate the effect of light [a long-day photoperiod (16 h light/8 h dark cycle)] and dark treatment on the production of rosmarinic acid in P. frutescens microgreens and to determine its antioxidant and antibacterial activities. Microgreens of P. frutescens were grown under light and dark conditions and harvested after 10, 15, 20, and 25 days of each treatment. Although dry weight values of microgreens gradually increased from 10 to 25 days of both treatments, the microgreens grown under light treatment possessed slightly higher levels of dry weight than those grown in the dark. Rosmarinic acid and total phenolic content (TPC) were also analyzed using high-performance liquid chromatography (HPLC) and Folin–Ciocalteu assay. The accumulation patterns of rosmarinic acid and TPC gradually increased and decreased, respectively, in P. frutescens microgreens grown in continuous darkness. The highest accumulation was observed in microgreens grown for 20 days. However, rosmarinic acid and TPC values were not significantly different in microgreens grown under light conditions. According to the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical inhibition assay, the extracts of P. frutescens microgreens were confirmed to be strong antioxidants, and their ability to scavenge DPPH radicals was positively correlated with the total phenolic content in the microgreens after 10, 15, 20, and 25 days of both treatments. Considering the relatively higher values of dry weight, rosmarinic acid, TPC, and DPPH assay, P. frutescens microgreens after 20 days of darkness and 20 days of light treatment, respectively, were selected for screening antibacterial activity using nine pathogens. Both microgreen extracts showed strong antibacterial activity against pathogens. In particular, the extracts of microgreens grown for 20 days under light treatment showed higher antimicrobial effects. Therefore, the light treatments for 20 days, as well as the darkness treatment for 20 days, were the best conditions for P. frutescens microgreen production because of their high levels of dry weight, phenolics, and biological activities. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Natural Compounds)

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10 pages, 648 KiB

Open AccessArticle

Antibiotic-Potentiating Activity of the Schinus terebinthifolius Raddi Essential Oil against MDR Bacterial Strains

by Maria Milene Costa da Silva, José Bezerra de Araújo Neto, Antonia Thassya Lucas dos Santos, Cícera Datiane de Morais Oliveira-Tintino, Ana Carolina Justino de Araújo, Priscilla Ramos Freitas, Luiz Everson da Silva, Wanderlei do Amaral, Cícero Deschamps, Francisco Roberto de Azevedo, Clara Mariana Gonçalves Lima, Nadezhda Golubkina, João Tavares Calixto-Júnior, Jaime Ribeiro-Filho, Henrique Douglas Melo Coutinho, Gianluca Caruso and Saulo Relison Tintino

Plants 2023, 12(8), 1587; https://doi.org/10.3390/plants12081587 - 08 Apr 2023

Cited by 4 | Viewed by 1934

Abstract

Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus are the primary bacteria that cause clinical infections, such as urinary and intestinal infections, pneumonia, endocarditis, and sepsis. Bacterial resistance is an innate natural occurrence in microorganisms, resulting from mutations or the lateral exchange [...] Read more.

Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus are the primary bacteria that cause clinical infections, such as urinary and intestinal infections, pneumonia, endocarditis, and sepsis. Bacterial resistance is an innate natural occurrence in microorganisms, resulting from mutations or the lateral exchange of genetic material. This serves as evidence for the association between drug consumption and pathogen resistance. Evidence has demonstrated that the association between conventional antibiotics and natural products is a promising pharmacological strategy to overcome resistance mechanisms. Considering the large body of research demonstrating the significant antimicrobial activities of Schinus terebinthifolius Raddi, the present study aimed to evaluate the chemical composition and antibiotic-enhancing effects of Schinus terebinthifolius Raddi essential oil (STEO) against the standard and multidrug-resistant strains of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The STEO was extracted by hydrodistillation using a Clevenger-type vacuum rotary evaporator. The Minimum Inhibitory Concentration (MIC) of the STEO was assessed by the microdilution method to evaluate the antibacterial activity. The antibiotic-enhancing activity of the essential oil was assessed by determining the MIC of antibiotics in the presence of a sub-inhibitory concentration (MIC/8) of the natural product. The GC-MS analysis revealed alpha-pinene (24.3%), gamma-muurolene (16.6%), and myrcene (13.7%) as major constituents of the STEO. The STEO potentiated the enhanced antibacterial activity of norfloxacin and gentamicin against all the strains and increased the action of penicillin against the Gram-negative strains. Therefore, it is concluded that although the STEO does not exhibit clinically effective antibacterial activity, its association with conventional antibiotics results in enhanced antibiotic activity. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Natural Compounds)

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16 pages, 2432 KiB

Open AccessArticle

Essential Oil of Lavandula officinalis: Chemical Composition and Antibacterial Activities

by Khaoula Diass, Mohammed Merzouki, Kaoutar Elfazazi, Hanane Azzouzi, Allal Challioui, Khalil Azzaoui, Belkheir Hammouti, Rachid Touzani, Flore Depeint, Alicia Ayerdi Gotor and Larbi Rhazi

Plants 2023, 12(7), 1571; https://doi.org/10.3390/plants12071571 - 06 Apr 2023

Cited by 10 | Viewed by 4113

Abstract

The purpose of this study was to determine the chemical composition of the essential oil of Lavandula officinalis from Morocco using the GC-MS technique and assess the antibacterial effects against seven pathogenic bacteria strains isolated from the food origins of Salmonella infantis, [...] Read more.

The purpose of this study was to determine the chemical composition of the essential oil of Lavandula officinalis from Morocco using the GC-MS technique and assess the antibacterial effects against seven pathogenic bacteria strains isolated from the food origins of Salmonella infantis, Salmonella kentucky, Salmonella newport, three serotypes of Escherichia coli (O114H8K11, O127K88ac, O127H40K11) and Klebsiella. Tests of sensitivity were carried out on a solid surface using the Disc Diffusion Method. Results showed that E. coli and S.newport were sensitive to Lavandula officinalis essential oil. Minimum inhibitory concentrations (MIC) were determined using the method of agar dilution. The antibacterial results showed that four strains (three serotypes of E. coli, and S. newport) were remarkedly sensitive to Lavandula officinalis essential oil, giving MIC values of 88.7 µg/mL and 177.5 µg/mL. The molecular docking of the main oil products with the E. coli target protein 1VLY, showed that eucalyptol and linalyl acetate bind efficiently with the active site of the target protein. In particular, eucalyptol showed a higher activity than gentamicin used as positive control with a binding energy of −5.72 kcal/mol and −5.55 kcal/mol, respectively. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Natural Compounds)

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18 pages, 2008 KiB

Open AccessArticle

Chemical Composition and Biological Activities of Eucalyptus globulus Essential Oil

by Natália Čmiková, Lucia Galovičová, Marianna Schwarzová, Milena D. Vukic, Nenad L. Vukovic, Przemysław Łukasz Kowalczewski, Ladislav Bakay, Maciej Ireneusz Kluz, Czeslaw Puchalski and Miroslava Kačániová

Plants 2023, 12(5), 1076; https://doi.org/10.3390/plants12051076 - 28 Feb 2023

Cited by 9 | Viewed by 4565

Abstract

Eucalyptus globulus essential oil (EGEO) is considered as a potential source of bioactive compounds with significant biological activity. The aim of this study was to analyze the chemical composition of EGEO, in vitro and in situ antimicrobial activity, antibiofilm activity, antioxidant activity, and [...] Read more.

Eucalyptus globulus essential oil (EGEO) is considered as a potential source of bioactive compounds with significant biological activity. The aim of this study was to analyze the chemical composition of EGEO, in vitro and in situ antimicrobial activity, antibiofilm activity, antioxidant activity, and insecticidal activity. The chemical composition was identified using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The main components of EGEO were 1,8-cineole (63.1%), p-cimene (7.7%), a-pinene (7.3%), and a-limonene (6.9%). Up to 99.2% of monoterpenes were present. The antioxidant potential of essential oil and results indicate that 10 μL of this sample can neutralize 55.44 ± 0.99% of ABTS^•+, which is equivalent to 3.22 ± 0.01 TEAC. Antimicrobial activity was determined via two methods: disk diffusion and minimum inhibitory concentration. The best antimicrobial activity was shown against C. albicans (14.00 ± 1.00 mm) and microscopic fungi (11.00 ± 0.00 mm–12.33 ± 0.58 mm). The minimum inhibitory concentration showed the best results against C. tropicalis (MIC 50 2.93 µL/mL, MIC 90 3.17 µL/mL). The antibiofilm activity of EGEO against biofilm-forming P. flourescens was also confirmed in this study. The antimicrobial activity in situ, i.e., in the vapor phase, was significantly stronger than in the contact application. Insecticidal activity was also tested and at concentrations of 100%, 50%, and 25%; the EGEO killed 100% of O. lavaterae individuals. EGEO was comprehensively investigated in this study and information regarding the biological activities and chemical composition of the essential oil of Eucalyptus globulus was expanded. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Natural Compounds)

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17 pages, 9453 KiB

Open AccessArticle

Evaluation of the Antibacterial Properties of Polyvinyl Alcohol-Pullulan Scaffolds Loaded with Nepeta racemosa Lam. Essential Oil and Perspectives for Possible Applications

by Constantin Lungoci, Cristina Mihaela Rîmbu, Iuliana Motrescu, Diana Serbezeanu, Cristina Elena Horhogea, Tăchiță Vlad-Bubulac, Carmen Simona Ghițău, Ioan Puiu, Andra-Sabina Neculai-Văleanu and Teodor Robu

Plants 2023, 12(4), 898; https://doi.org/10.3390/plants12040898 - 16 Feb 2023

Cited by 3 | Viewed by 1419

Abstract

Essential oil of Nepeta racemosa Lam. was extracted and characterized to determine its antimicrobial activity and potential use in applications. The essential oil was loaded on polyvinyl alcohol-pullulan films and gels and characterized by optical microscopy, scanning electron microscopy, and UV-Vis spectroscopy before [...] Read more.

Essential oil of Nepeta racemosa Lam. was extracted and characterized to determine its antimicrobial activity and potential use in applications. The essential oil was loaded on polyvinyl alcohol-pullulan films and gels and characterized by optical microscopy, scanning electron microscopy, and UV-Vis spectroscopy before having its antimicrobial capacities assessed. The essential oil extracted from Nepeta racemosa Lam. was characterized using gas chromatography coupled with mass spectroscopy, which indicated that the most abundant component was nepetalic acid (55.5%), followed by eucalyptol (10.7%) and other compounds with concentrations of about 5% or less. The essential oil, as well as the loaded films and gels, exhibited good antibacterial activity on both gram-positive and gram-negative strains, with growth inhibition zones larger in some cases than for gentamicin, indicating excellent premises for using these essential-oil-loaded materials for applications in the food industry or biomedicine. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Natural Compounds)

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11 pages, 1165 KiB

Open AccessArticle

Effects of Carbohydrates on Rosmarinic Acid Production and In Vitro Antimicrobial Activities in Hairy Root Cultures of Agastache rugosa

by Hyeon Ji Yeo, Min Jae Kwon, Sang Yeon Han, Jae Cheol Jeong, Cha Young Kim, Sang Un Park and Chang Ha Park

Plants 2023, 12(4), 797; https://doi.org/10.3390/plants12040797 - 10 Feb 2023

Cited by 7 | Viewed by 1644

Abstract

Agastache rugosa (popularly known as Korean mint) belongs to the Lamiaceae family and comprises 22 species of perennial aromatic medicinal species native to East Asian countries, such as Korea, Taiwan, Japan, and China. A. rugosa contains many phenolic compounds that exhibit pharmacological and [...] Read more.

Agastache rugosa (popularly known as Korean mint) belongs to the Lamiaceae family and comprises 22 species of perennial aromatic medicinal species native to East Asian countries, such as Korea, Taiwan, Japan, and China. A. rugosa contains many phenolic compounds that exhibit pharmacological and physiological activities, including antioxidant, anticancer, antiviral, antifungal, and antibacterial activities. The highest concentrations of rosmarinic acid and its isomers have been reported in the roots of A. rugosa. In this in vitro study, hairy roots of A. rugosa were obtained and the carbohydrates (sorbitol, mannitol, glucose, maltose, galactose, mannose, and sucrose) were evaluated to determine those that were optimal for rosmarinic acid production and hairy root growth. Antioxidant and antibacterial activities of extracts of A. rugosa were also assessed. The best carbon source for A. rugosa hairy root cultures was sucrose, considering biomass productivity (0.460 ± 0.034 mg/30 mL), rosmarinic acid production (7.656 ± 0.407 mg/g dry weight), and total phenolic content (12.714 ± 0.202 mg/g gallic acid equivalent). Antioxidant and antimicrobial activities were displayed by A. rugosa hairy roots cultured in liquid medium supplemented with 100 mM sucrose. Twenty-five bacterial strains, including multidrug-resistant bacteria and one pathogenic yeast strain, were used for antimicrobial screening of A. rugosa hairy roots. The hairy root extracts displayed antibacterial activity against Micrococcus luteus (KCTC 3063) and Bacillus cereus (KCTC 3624). The inhibition of these bacteria was greater using A. rugosa hairy roots with the highest levels of phenolic compounds cultured in the presence of sucrose, compared to hairy roots with the lowest levels of phenolic compounds cultured in the presence of fructose. Considering hairy root biomass, phenolic compound production, and antibacterial activity, sucrose is the best carbon source for A. rugosa hairy root cultures. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Natural Compounds)

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17 pages, 5334 KiB

Open AccessArticle

The Anti-Candida Activity of Tephrosia apollinea Is More Superiorly Attributed to a Novel Steroidal Compound with Selective Targeting

by Naglaa S. Ashmawy, Eman M. El-labbad, Alshaimaa M. Hamoda, Ali A. El-Keblawy, Abdel-Nasser A. El-Shorbagi, Kareem A. Mosa and Sameh S. M. Soliman

Plants 2022, 11(16), 2120; https://doi.org/10.3390/plants11162120 - 15 Aug 2022

Cited by 5 | Viewed by 1709

Abstract

Tephrosia is widely distributed throughout tropical, subtropical, and arid regions. This genus is known for several biological activities, including its anti-Candida activity, which is mainly attributed to prenylated flavonoids. The biological activities of most Tephrosia species have been studied, except T. apollinea [...] Read more.

Tephrosia is widely distributed throughout tropical, subtropical, and arid regions. This genus is known for several biological activities, including its anti-Candida activity, which is mainly attributed to prenylated flavonoids. The biological activities of most Tephrosia species have been studied, except T. apollinea. This study was conducted to investigate the underlying anti-Candida activity of T. apollinea, wildly grown in the United Arab Emirates (UAE). The T. apollinea plant was collected, dried, and the leaves were separated. The leaves were ground and extracted. The dried extract was subjected to successive chromatography to identify unique phytochemicals with a special pharmacological activity. The activity of the compound was validated by homology modeling and molecular docking studies. A novel steroidal compound (ergosta-6, 8(14), 22, 24(28)-tetraen-3-one) was isolated and named TNS. In silico target identification of TNS revealed a high structural similarity with the Candida 14-α-demethylase enzyme substrate. The compound exhibited a significant anti-Candida activity, specifically against the multi-drug-resistant Candida auris at MIC₅₀, 16 times less than the previously reported prenylated flavonoids and 5 times less than the methanol extract of the plant. These findings were supported by homology modeling and molecular docking studies. TNS may represent a new class of Candida 14-α-demethylase inhibitors. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Natural Compounds)

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Review

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37 pages, 424 KiB

Open AccessReview

Plant as an Alternative Source of Antifungals against Aspergillus Infections: A Review

by Lee Fang Tan, Vi Lien Yap, Mogana Rajagopal, Christophe Wiart, Malarvili Selvaraja, Mun Yee Leong and Puay Luan Tan

Plants 2022, 11(22), 3009; https://doi.org/10.3390/plants11223009 - 08 Nov 2022

Cited by 7 | Viewed by 5791

Abstract

Aspergillus species consists of a group of opportunistic fungi that is virulent when the immunity of the host is compromised. Among the various species, Aspergillus fumigatus is the most prevalent species. However, the prevalence of fungal infections caused by non-fumigatus Aspergillus has been [...] Read more.

Aspergillus species consists of a group of opportunistic fungi that is virulent when the immunity of the host is compromised. Among the various species, Aspergillus fumigatus is the most prevalent species. However, the prevalence of fungal infections caused by non-fumigatus Aspergillus has been increasing. Polyenes, echinocandins and azoles are the three main classes of antifungal agents being used for the treatment of aspergillosis. Nevertheless, the incidence of resistance towards these three classes has been rising over the years among several Aspergillus spp. The side effects associated with these conventional antifungal agents have also limited their usage. This urges the need for the discovery of a safe and effective antifungal agent, which presents a major challenge in medicine today. Plants present a rich source of bioactive molecules which have been proven effective against a wide range of infections and conditions. Therefore, this present review intends to examine the current literature available regarding the efficacy and mechanism of action of plant extracts and their compounds against Aspergillus spp. In addition, novel drug delivery systems of plant extracts against Aspergillus spp. were also included in this review. Full article

(This article belongs to the Special Issue Antimicrobial Activity of Natural Compounds)

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