Antioxidant and Medicinal Properties of Natural Products

A special issue of Processes (ISSN 2227-9717). This special issue belongs to the section "Pharmaceutical Processes".

Deadline for manuscript submissions: closed (20 February 2022) | Viewed by 14676

Special Issue Editor


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Guest Editor
Division of Endocrinology, Department of Internal Medicine, University of Patras, 26504 Patras, Greece
Interests: diabetes; obesity; metabolism; oxidative stress; thyroid cancer metabolism; natural products; Keap1/Nrf2 pathway
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Special Issue Information

Dear Colleagues,

There is growing interest in the use and study of natural products for the prevention and treatment of various diseases such as, but not limited to, obesity, diabetes, neurodegenerative diseases, autoimmune disorders, chronic kidney diseases and cancer. Chronic oxidative stress and/or inflammation are at least partially the pathophysiological basis for most of these diseases. Although there are several therapeutic options available, the use of naturally occurring compounds is investigated as they may be safer alternatives in the long-term for prevention in a healthy population in the form of dietary supplements and can comprise more affordable treatments in developing countries. Advances in analytical chemistry have allowed scientists to identify the compounds that are present in dietary supplements and traditional natural formulas and study them in the lab and in clinics. Sulforaphane, withaferin A and resveratrol are a few examples of naturally occurring compounds with antioxidant properties that have been used in preclinical and clinical trials.

The present Special Issue titled “Antioxidant and Medicinal Properties of Natural Products” seeks high-quality basic, translational and clinical studies that employ natural products with antioxidant potential and can be used for disease treatment and prevention. Topics include but are not limited to:

  • In vitro studies using natural compounds and suggesting their potential mechanism of action (e.g., activation of antioxidant pathways such as Keap1/Nrf2, reduced production of reactive oxygen species, inhibition of inflammation);
  • Animal models of disease treated with natural products and study of their effects on phenotype, physiological–pathophysiological processes and pathways;
  • Translational and clinical studies employing natural compounds for prevention and treatment of diseases such as diabetes, obesity, cancer, autoimmune and neurodegenerative diseases and others;
  • Mini or full-length reviews on the use of natural products against these diseases. 

Dr. Dionysios V. Chartoumpekis
Guest Editor

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Processes is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • oxidative stress
  • natural compounds
  • Nrf2
  • dietary supplements
  • chronic inflammation
  • cytoprotection
  • treatment
  • prevention
  • molecular mechanisms

Published Papers (4 papers)

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Research

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23 pages, 4956 KiB  
Article
Potential Antioxidant and Anticancer Activities of Secondary Metabolites of Nostoc linckia Cultivated under Zn and Cu Stress Conditions
by Khaled M. A. Ramadan, Hossam S. El-Beltagi, Sanaa M. M. Shanab, Eman A. El-fayoumy, Emad A. Shalaby and Eslam S. A. Bendary
Processes 2021, 9(11), 1972; https://doi.org/10.3390/pr9111972 - 04 Nov 2021
Cited by 13 | Viewed by 2008
Abstract
The objective of the present study is to determine the antioxidant and anticancer activities of Nostoc linckia extracts cultivated under heavy metal stress conditions (0.44, 0.88, and 1.76 mg/L for zinc and 0.158, 0.316, 0.632 mg/L for copper). Phycobiliprotein, phenolic compounds, flavonoids, and [...] Read more.
The objective of the present study is to determine the antioxidant and anticancer activities of Nostoc linckia extracts cultivated under heavy metal stress conditions (0.44, 0.88, and 1.76 mg/L for zinc and 0.158, 0.316, 0.632 mg/L for copper). Phycobiliprotein, phenolic compounds, flavonoids, and tannins were measured. Active ingredients of extracts were evaluated by GC-mass spectroscopy. The obtained results revealed that higher zinc and copper concentrations showed growth inhibition while 0.22 mg/L (Zn) and 0.079 mg/L (Cu) enhanced growth, reaching its maximum on the 25th day. Increases in catalase, lipids peroxidation, and antioxidants, as well as tannins and flavonoids, have been induced by integration of 0.88 mg/L (Zn) and 0.316 mg/L (Cu). Elevation of Zn concentration induced augmentation of antioxidant activity of crude extract (DPPH or ABTS), with superior activity at 0.44 mg/L zinc concentration (81.22%). The anticancer activity of Nostoc linckia extract (0.44 mg/L Zn) tested against four cancer cell lines: A549, Hela, HCT 116, and MCF-7. The extract at 500 µg/mL appeared the lowest cell viability of tested cell lines. The promising extract (0.44 mg/L Zn) recorded the lowest cell viability of 25.57% in cervical cell line, 29.74% in breast cell line, 33.10% in lung cell line and 34.53% in the colon cell line. The antioxidant active extract showed significant stability against pH with attributed increase in antioxidant activity in the range between 8–12. The extract can be used effectively as a natural antioxidant and anticancer after progressive testing. Full article
(This article belongs to the Special Issue Antioxidant and Medicinal Properties of Natural Products)
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19 pages, 8172 KiB  
Article
Galangin Attenuates Liver Injury, Oxidative Stress and Inflammation, and Upregulates Nrf2/HO-1 Signaling in Streptozotocin-Induced Diabetic Rats
by Wesam Al-Amarat, Mohammad H. Abukhalil, Osama Y. Althunibat, Manal A. Alfwuaires, Mashael M. Alnamshan, Amany I. Alqosaibi, Ahmad F. Ahmeda, Emadeldin M. Kamel, Hany H. Arab and Ayman M. Mahmoud
Processes 2021, 9(9), 1562; https://doi.org/10.3390/pr9091562 - 01 Sep 2021
Cited by 13 | Viewed by 2852
Abstract
Chronic hyperglycemia increases the risk of liver damage. Oxidative stress and aberrant inflammatory response are entangled in diabetes-associated liver injury. This study evaluated the protective effect of the flavonoid galangin (Gal) on glucose intolerance, liver injury, oxidative stress, inflammatory response, and Nrf2/HO-1 signaling [...] Read more.
Chronic hyperglycemia increases the risk of liver damage. Oxidative stress and aberrant inflammatory response are entangled in diabetes-associated liver injury. This study evaluated the protective effect of the flavonoid galangin (Gal) on glucose intolerance, liver injury, oxidative stress, inflammatory response, and Nrf2/HO-1 signaling in diabetic rats. Diabetes was induced by streptozotocin (STZ), and the rats received Gal for six weeks. STZ-induced rats showed glucose intolerance, hypoinsulinemia, elevated glycated hemoglobin (HbA1c), and decreased liver glycogen. Gal ameliorated glucose intolerance, reduced HbA1c%, increased serum insulin and liver glycogen and hexokinase activity, and suppressed glycogen phosphorylase, glucose-6-phosphatase and fructose-1,6-biphosphatase in diabetic rats. Circulating transaminases, ALP and LDH, and liver ROS, MDA, TNF-α, IL-1β, and IL-6 were increased and GSH, SOD, and CAT were diminished in diabetic rats. In addition, diabetic rats exhibited multiple histopathological alterations and marked collagen deposition. Treatment with Gal mitigated liver injury, prevented histopathological alterations, decreased ROS, MDA, pro-inflammatory cytokines, Bax and caspase-3, and enhanced cellular antioxidants and Bcl-2. Gal downregulated hepatic Keap1 in diabetic rats and upregulated Nrf2 and HO-1 mRNA as well as HO-1 activity. Molecular modeling studies revealed the ability of Gal to bind to and inhibit NF-κB and Keap1, and also showed its binding pattern with HO-1. In conclusion, Gal ameliorates hyperglycemia, glucose intolerance, oxidative stress, inflammation, and apoptosis in diabetic rats. Gal improved carbohydrate metabolizing enzymes and upregulated Nrf2/HO-1 signaling. Full article
(This article belongs to the Special Issue Antioxidant and Medicinal Properties of Natural Products)
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11 pages, 919 KiB  
Article
Phytochemical Screening and Antimicrobial Activity of Various Extracts of Aerial Parts of Rhanterium epapposum
by Saravanan Rajendrasozhan, Hani El Moll, Mejdi Snoussi, Ramy M. Romeilah, Emad A. Shalaby, Kareem M. Younes and Hossam S. El-Beltagi
Processes 2021, 9(8), 1351; https://doi.org/10.3390/pr9081351 - 31 Jul 2021
Cited by 14 | Viewed by 3119
Abstract
Rhanterium epapposum, native to the Arabian Peninsula, is traditionally used to cure skin infections. The objective is to screen the phytochemical content and antimicrobial activity of aqueous, methanol and 80% methanol extracts of aerial parts of R. epapposum. The phytochemical screening [...] Read more.
Rhanterium epapposum, native to the Arabian Peninsula, is traditionally used to cure skin infections. The objective is to screen the phytochemical content and antimicrobial activity of aqueous, methanol and 80% methanol extracts of aerial parts of R. epapposum. The phytochemical screening of aqueous, methanolic, and 80% methanol extracts of R. epapposum was conducted using gas chromatographymass spectrometry. The antimicrobial activities of the extracts were assessed by well diffusion and microdilution methods. Qualitative phytochemical analysis revealed the presence of 2-methoxy-4-vinylphenol in all three extracts, whereas ethanol, 2-methoxy-, acetate; n-hexadecanoic acid; and 2,3-butanediol are present in higher amount exclusively in the methanol, 80% methanol and aqueous extracts of the aerial parts of R. epapposum, respectively. The highest antibacterial activity was shown by the aqueous extract S. aureus, P. aeruginosa, E. cloacae, and K. pneumoniae, methanolic extract against S. aureus, methicillin-resistant S. aureus, and E. coli, and 80% methanol extract against S. epidermidis, and S. paucimobilis. Interestingly, 80% methanol extracts showed the highest antifungal activity against C. albicans, C. guillermondii, C. vaginalis, C. utilis, and C. tropicalis. The aerial parts of R. epapposum showed broad-spread antimicrobial activity against bacteria and fungi. Especially, the 80% methanol extract showed potent antifungal activity against all the tested fungal strains. Full article
(This article belongs to the Special Issue Antioxidant and Medicinal Properties of Natural Products)
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Review

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16 pages, 1696 KiB  
Review
Impact of Zinc, Glutathione, and Polyphenols as Antioxidants in the Immune Response against SARS-CoV-2
by José Manuel Pérez de la Lastra, Celia Andrés-Juan, Francisco J. Plou and Eduardo Pérez-Lebeña
Processes 2021, 9(3), 506; https://doi.org/10.3390/pr9030506 - 11 Mar 2021
Cited by 13 | Viewed by 5571
Abstract
SARS-CoV-2, the coronavirus triggering the disease COVID-19, has a catastrophic health and socioeconomic impact at a global scale. Three key factors contribute to the pathogenesis of COVID-19: excessive inflammation, immune system depression/inhibition, and a set of proinflammatory cytokines. Common to these factors, a [...] Read more.
SARS-CoV-2, the coronavirus triggering the disease COVID-19, has a catastrophic health and socioeconomic impact at a global scale. Three key factors contribute to the pathogenesis of COVID-19: excessive inflammation, immune system depression/inhibition, and a set of proinflammatory cytokines. Common to these factors, a central function of oxidative stress has been highlighted. A diversity of clinical trials focused predominantly on antioxidants are being implemented as potential therapies for COVID-19. In this study, we look at the role of zinc, glutathione, and polyphenols, as key antioxidants of possible medicinal or nutritional significance, and examine their role in the antiviral immune response induced by SARS-Cov-2. An unresolved question is why some people experience chronic COVID and others do not. Understanding the relationship between SARS-CoV-2 and the immune system, as well as the role of defective immune responses to disease development, would be essential to recognize the pathogenesis of COVID-19, the risk factors that affect the harmful consequences of the disease, and the rational design of successful therapies and vaccinations. We expect that our research will provide a novel perspective that contributes to the design of clinical or nutritional targets for the prevention of this pandemic. Full article
(This article belongs to the Special Issue Antioxidant and Medicinal Properties of Natural Products)
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