bims-antpol Biomed News
on Antiviral properties of polyphenols
Issue of 2024–11–03
five papers selected by
Rick Sheridan, EMSKE Phytochem



  1. Food Sci Nutr. 2024 Oct;12(10): 7671-7682
      Influenza viruses pose significant public health threats because they can cause seasonal outbreaks and global pandemics. Current preventive measures, including vaccines and antiviral drugs, are limited by their low efficacy and the emergence of drug-resistant viruses. Addressing these issues necessitates the development of novel preventive and treatment methods. Our previous work highlighted the inhibitory effects of soybean hydrothermal extract on influenza virus growth. In this study, we aimed to delve into the mechanism underlying the antiviral activity, specifically the inhibition of viral entry. Our findings reveal that soybean extract significantly inhibited the stages of viral entry during a viral infection and hindered virus uptake by cells. Fluorescence microscopy of stained viral nucleoproteins demonstrated viral localization on the cell membrane in soybean-treated cells, highlighting a distinctive pattern compared to the control cells where the virus was internalized. Soybean extract targeted the clathrin-dependent endocytosis pathway, as evidenced by 76% inhibition using a clathrin-dependent marker (transferrin). The identification of soybean inhibitors underscores the need for further investigation and offers potential for innovative antiviral interventions.
    Keywords:  clathrin‐dependent endocytosis; influenza virus; soybean; virus entry; virus infection inhibition
    DOI:  https://doi.org/10.1002/fsn3.4324
  2. Sci Rep. 2024 10 29. 14(1): 25922
      Despite being a global public health problem, there are no antiviral agents for dengue. Plants are the sources of most approved drugs and many phytochemicals have exhibited in vitro antiviral activity. We explored the antiviral potential of the aqueous extract of Glycyrrhiza glabra roots (GGaq) on dengue viruses. Plaque reduction antiviral assay for half maximal inhibitory concentrations (IC50) was done in Vero cells infected with dengue serotypes 1-4 and exposed to varying concentrations of GGaq. Half-maximal cytotoxic concentration (CC50) of the GGaq was 651.9 µg/mL. The IC50 of the four dengue serotypes (10-50 µg/mL) indicated moderate inhibition by GGaq. 98-100% inhibition of all dengue serotypes was seen with GGaq at the maximum nontoxic dose. Preparative thin layer chromatography of GGaq, isolated sub fractions E and F which had low to moderate antiviral activity (IC50 12.65-85.95 and IC50 13.14-69.27 respectively). They exhibited good therapeutic potential only for dengue serotype-4. Virus adsorption to cells was significantly inhibited by GG (50%) and sub fraction E (24.9%). Chloroquine diphosphate was used as the positive control in all assays. The aqueous extract of GG was non-toxic and had better antiviral activity than sub fractions E and F.
    Keywords:   Glycyrrhiza glabra ; Antiviral; Dengue; Fractionation; Vero cell
    DOI:  https://doi.org/10.1038/s41598-024-76184-5
  3. Plants (Basel). 2024 Oct 15. pii: 2881. [Epub ahead of print]13(20):
      Dengue is an emerging disease of high impact on human health. Plants are an important source of new antivirals and Arachis hypogaea stands for its biological properties. The aim of this study was to evaluate the cytotoxicity and antiviral activity and elucidate the antiviral mechanism of ethanolic extracts from A. hypogaea against dengue virus 2 (DENV-2). The skin or tegument ethanolic extract (TEEs) and seed ethanolic extract (SEEs) were obtained. Cytotoxicity was evaluated by MTT and Neutral Red Uptake (NRU). Antiviral activity was evaluated at different stages of the viral replication cycle by the lysis plaque reduction method. The 50% inhibitory concentration (IC50) and selectivity index (SI) were determined. Antiviral activity was further determined by RT-qPCR. The CC50 values were 169 (NRU) and 65 (MTT) µg/mL for TEE. In addition, the CC50 values were >1400 (NRU) and 636 (MTT) µg/mL for SEE. The TEE demonstrated 99.9 ± 0.1% viral inhibition. The TEE presented an IC50 = 3.47 and SI of 48.7 (NRU) and 18.73 (MTT). Its mechanism of antiviral action is broad and it acts in the viral adsorption-penetration stage and inhibits the first steps of infection in the post-penetration stage. It is also capable of acting as virucidal and as prophylactic. Studies of RT-qPCR indicated that the TEE inhibited viral RNA synthesis. These findings suggest that the TEE from A. hypogaea could be a promising antiviral candidate for treating DENV-2 infections.
    Keywords:  Arachis hypogaea L.; antiviral; caffeic acid; cytotoxicity; dengue virus serotype 2; linoleic acid
    DOI:  https://doi.org/10.3390/plants13202881
  4. Acta Pharmacol Sin. 2024 Oct 30.
      Baicalin (BA), a natural component found in many traditional Chinese medicines, exerts protective effects against several viruses. Although our previous studies have revealed that the anti-hepatitis B virus (anti-HBV) activity of BA depends on hepatocyte nuclear factor (HNF) signaling, the specific mechanisms remain unclear. The present study explored the potential signaling mechanisms involved in BA-mediated HBV suppression. Transcriptomic analysis suggested that BA significantly modulates the estrogen receptor (ER) and AMPK signaling pathways in HepG2 cells. The ER alpha (ERα) binding affinity of BA and its estrogen-like agonist activity were subsequently verified through molecular docking assays, BA-ERα affinity detection experiments, ERα luciferase reporter gene assays, and qRT-PCR. ERα knockdown (shRNA) and AMPK inhibition (Compound C and doxorubicin [Dox]) experiments revealed that the sequential activation of the ERα-LKB1-AMPK-HNF signaling axis is essential for the anti-HBV effects of BA. This study indicates that BA may trigger the ERα-AMPKα-HNF pathway to inhibit HBV replication, providing insights into its potential protective mechanisms against other viruses.
    Keywords:  AMPKα; ERα; antiviral flavonoid; baicalin; hepatitis B virus; hepatocyte nuclear factor
    DOI:  https://doi.org/10.1038/s41401-024-01408-3
  5. Antioxidants (Basel). 2024 Oct 10. pii: 1220. [Epub ahead of print]13(10):
      Polyphenols are organic chemical compounds naturally present in plants, renowned for their anti-inflammatory, antioxidant, immunomodulatory, anticancer, and cardiovascular protective properties. Their bioactivity and bioavailability can vary widely depending on the methods of food processing and interactions with the gut microbiome. These factors can induce changes in polyphenols, affecting their ability to achieve their intended health benefits. Thus, it is essential to develop and apply food processing methods that optimize polyphenol content while maintaining their bioactivity and bioavailability. This review aims to explore how various food processing techniques affect the quantity, bioactivity, and bioavailability of polyphenols, as well as their interactions with the gut microbiome, which may ultimately determine their health effects.
    Keywords:  bioactivity; bioavailability; food processing; microbiome; polyphenols
    DOI:  https://doi.org/10.3390/antiox13101220