bims-antpol Biomed News
on Antiviral properties of polyphenols
Issue of 2023–06–04
five papers selected by
Rick Sheridan, EMSKE Phytochem



  1. J Agric Food Chem. 2023 May 30.
      Consumption of fruits and vegetables has been associated with a reduced risk of multiple diseases, such as metabolic disorders. Flavonols are the most ubiquitous flavonoids in fruits and vegetables. However, dietary flavonols exhibit a general low oral bioavailability for their extensive biotransformation mediated by phase II enzymes in enterocytes and liver as well as by microbiota in the gut lumen. In this context, flavonols have brought attention to a paradox between low bioavailability and health-promoting effects. Flavonols are often transformed prior to absorption, which could change their biological activity. Compared to their parent compounds, the corresponding metabolites of flavonols in vivo might exhibit similar or higher intrinsic bioactivities, or perhaps a decreased efficacious effectiveness. Indeed, a growing body of evidence from biological function studies of metabolites supports the positive and significant contribution of in vivo metabolic processes, particularly conversion mediated by gut microbiota, to the health-promoting benefits of flavonols. As such, further understanding of the metabolic fate of flavonols and biological activities of their metabolites as well as the possible impact of microbiota-mediated conversion on the bioactivity is of great significance to guide a rational diet with flavonol-rich fruits and vegetables and/or flavonol-containing functional foods.
    Keywords:  bioactivity; bioavailability; flavonols; gut microbiota; metabolism
    DOI:  https://doi.org/10.1021/acs.jafc.3c01087
  2. J Pharm Biomed Anal. 2023 May 18. pii: S0731-7085(23)00238-8. [Epub ahead of print]233 115469
      Flavonoids widely exist in a large number of Chinese herbal medicines with antiviral and anti-inflammatory properties. Houttuynia cordata Thunb. is a traditional Chinese herbal medicine for heat-clearing and detoxification. In our previous research, total flavonoids from H. cordata (HCTF) effectively alleviated H1N1-induced acute lung injury (ALI) in mice. In this study, 8 flavonoids were recognized from HCTF (containing 63.06 % ± 0.26 % of total flavonoids, as quercitrin equivalents) by UPLC-LTQ-MS/MS. Four main flavonoid glycosides in HCTF (rutin, hyperoside, isoquercitrin and quercitrin) and their common aglycone quercetin (100 mg/kg) all showed therapeutic effects on H1N1-induced ALI in mice. The two flavonoids (hyperoside and quercitrin) with higher contents and quercetin showed stronger therapeutic effects on H1N1-induced ALI in mice. Hyperoside, quercitrin and quercetin significantly reduced the levels of pro-inflammatory factors, chemokines, or neuraminidase activity compared with the same dose of HCTF (p < 0.05). The results of mice intestinal bacteria biotransformation in vitro showed that quercetin was the main metabolite. The conversion rates of hyperoside and quercitrin were significantly higher by the intestinal bacteria under the pathological state (0.81 ± 0.02 and 0.91 ± 0.01, respectively) than normal state (0.18 ± 0.01 and 0.18 ± 0.12, respectively, p < 0.001). Our findings showed that hyperoside and quercitrin were the main efficacious components of HCTF for treating H1N1-induced ALI in mice and could be metabolized to quercetin by intestinal bacteria in pathological state to exert their effects.
    Keywords:  Flavonoid; H1N1; Houttuynia cordata; Intestinal bacteria; Metabolite; UPLC-MS/MS
    DOI:  https://doi.org/10.1016/j.jpba.2023.115469
  3. Arch Microbiol. 2023 May 30. 205(6): 252
      Inflammatory bowel disease (IBD) is a chronic recurrent inflammation of the gastrointestinal tract (GIT). IBD patients are susceptible to various infections such as viral infections due to the long-term consumption of immunosuppressive drugs and biologics. The antiviral and IBD protective traits of flavonoids have not been entirely investigated. This study objective included an overview of the protective role of flavonoids quercetin and silymarin in viral-associated IBD. Several viral agents such as cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella zoster virus (VZV) and enteric viruses can be reactivated and thus develop or exacerbate the IBD conditions or eventually facilitate the disease remission. Flavonoids such as quercetin and silymarin are non-toxic and safe bioactive compounds with remarkable anti-oxidant, anti-inflammatory and anti-viral effects. Mechanisms of anti-inflammatory and antiviral effects of silymarin and quercetin mainly include immune modulation and inhibition of caspase enzymes, viral binding and replication, RNA synthesis, viral proteases and viral assembly. In the nutraceutical sector, natural flavonoids low bioavailability and solubility necessitate the application of delivery systems to enhance their efficacy. This review study provided an updated understanding of the protective role of quercetin and silymarin against viral-associated IBD.
    Keywords:  Antiviral traits; Inflammatory bowel diseases; Quercetin; Silymarin; Viral infections
    DOI:  https://doi.org/10.1007/s00203-023-03590-0
  4. J Ethnopharmacol. 2023 May 26. pii: S0378-8741(23)00531-7. [Epub ahead of print]315 116663
       ETHNOPHARMACOLOGICAL RELEVANCE: Artemisia anomala S. Moore (family: Asteraceae) is a traditional herb that has been used for medicinal purposes in China for more than 1300 years. In traditional and local medicine, A. anomala is widely used in the treatment of rheumatic, dysmenorrhea, enteritis, hepatitis, hematuria and burn injury, and it is also considered as a natural botanical supplement in some areas, a traditional herb with both medicinal and edible properties.
    AIM OF THE REVIEW: The paper aims to provide a comprehensive overview of A. anomala, covering its botany, traditional uses, phytochemistry, pharmacological activity, and quality control, and to summarize the current research status in order to better understand the application value of A. anomala as a traditional herbal medicine and provide references for its further development and utilization.
    MATERIALS AND METHODS: The relevant information on A. anomala was collected by searching a range of literature and electronic databases using "Artemisia anomala" as the key search term. These sources included both ancient and modern books, the Chinese Pharmacopoeia, as well as various online databases such as PubMed, ScienceDirect, Wiley, ACS, CNKI, Springer, Taylor & Francis, Web of Science, Google Scholar, and Baidu Scholar.
    RESULTS: At present, 125 compounds have been isolated from A. anomala, including terpenoids, triterpenoids, flavonoids, phenylpropanoids, volatile oils and other compounds. Modern studies have confirmed that these active components have significant pharmacological activities, including anti-inflammatory, anti-bacterial, hepatoprotective, anti-platelet aggregation and anti-oxidation. In modern clinic, A. anomala is widely used in the treatment of rheumatoid arthritis, dysmenorrhea, irregular menstruation, traumatic bleeding, hepatitis, soft tissue contusion, burn and scald.
    CONCLUSIONS: Long-term traditional medicinal history and a large number of modern in vitro and in vivo studies have confirmed that A. anomala has a wide range of biological activities, which can provide rich resources for the discovery of promising drug candidates and the development of new plant supplements. However, the research on the active components and molecular mechanism of A. anomala is insufficient, and more mechanism-based pharmacological evaluation and clinical research should be carried out to provide a more powerful scientific basis for its traditional use. In addition, the index components and determination standards of A. anomala should be established as soon as possible, so as to establish a systematic and effective quality control system.
    Keywords:  Artemisia anomala S. Moore; Botany; Pharmacological activity; Phytochemistry; Quality control; Traditional uses
    DOI:  https://doi.org/10.1016/j.jep.2023.116663
  5. Food Res Int. 2023 07;pii: S0963-9969(23)00361-7. [Epub ahead of print]169 112816
      Oxidative stress and inflammation play a key role in diverse pathological conditions such as cancer and metabolic disorders. The objective of this study was to determine the antioxidant and anti-inflammatory potentials of crude extract (CE) and phenolic-enriched extract (PHE) obtained from the seed coats (SCs) of black bean (BB) and pinto bean (PB) varieties. Delphinidin-3-O-glucoside (46 mg/g SC), malvidin-3-O-glucoside (29.9 mg/g SC), and petunidin-3-O-glucoside (7.5 mg/g SC) were found in major concentrations in the PHE-BB. Pelargonidin (0.53 mg/g SC) was only identified in the PHE-PB. PHE from both varieties showed antioxidant and radical scavenging capacities, with strong correlations associated with total phenolic content (TPC). Polyphenolics, including catechin, myricetin, kaempferol, quercetin, and isorhamnetin glucosides, were identified in the extracts. In terms of the anti-inflammatory potentials, PHE-PB had an IC50 of 10.5 µg dry extract/mL (µg DE/mL) for cyclooxygenase-2 (COX-2) inhibition. The inhibition values for cyclooxygenase-1 (COX-1) ranged from 118.1 to 162.7 µg DE/mL. Regarding inducible nitric oxide synthase (iNOS) inhibition, PHE-BB had an IC50 of 62.6 µg DE/mL. As determined via in silico analysis, pelargonidin showed binding affinities of -7.8 and -8.5 kcal/mol for COX-1 and iNOS, respectively, and catechin had a value of -8.3 kcal/mol for COX-2. Phenolic-enriched extracts from seed coats of black and pinto beans showed good antioxidant and anti-inflammatory potential that warrants in vitro and in vivo studies.
    Keywords:  Anthocyanins; COX-1; COX-2; Common bean; In silico; Phenolic compound; Purification; Radical scavenging; iNOS
    DOI:  https://doi.org/10.1016/j.foodres.2023.112816