bims-antpol Biomed News
on Antiviral properties of polyphenols
Issue of 2024‒09‒15
two papers selected by
Rick Sheridan, EMSKE Phytochem



  1. Phytomedicine. 2024 Sep 01. pii: S0944-7113(24)00672-X. [Epub ahead of print]134 156015
      BACKGROUND: Pseudorabies virus (PRV), a member of the family Herpesviridae, is responsible for significant economic losses in the pig industry and has recently been associated with human viral encephalitis, leading to severe neurological symptoms post-recovery. Despite the widespread impact of PRV, there are currently no approved effective drugs for treating PRV-related diseases in humans or pigs. Therefore, the exploration and discovery of safe and effective drugs for the prevention and treatment of PRV infection is of paramount importance.PURPOSE: The objective of this study is to screen and identify natural compounds with antiviral activity against PRV.
    METHODS: First, we used a strain of PRV with green fluorescent protein (PRV-GFP) to screen a natural product chemical library to identify potential antiviral drugs. Next, we assessed the antiviral abilities of salvianolic acid A (SAA) in vitro using virus titer assay, qPCR, and IFA. We investigated the mechanisms of SAA's antiviral activity through viral attachment, internalization, inactivation, and nuclease digestion assay. Finally, we evaluated the efficacy of SAA in inactivating PRV using mice as the experimental subjects.
    RESULTS: This study screened 206 natural compounds for anti-PRV activity in vitro, resulting in the identification of seven potential antiviral agents. Notably, SAA emerged as a promising candidate with significant anti-PRV activity. The mechanism of action may be that SAA can directly inactivate the virus by disrupting viral envelope. In vivo experiments have shown that pre-incubation of SAA and PRV can effectively inhibit the infectivity and pathogenicity of PRV in mice.
    CONCLUSION: This study offers valuable insights into the antiviral properties of SAA, potentially informing strategies for controlling PRV epidemics and treating related diseases in both humans and animals.
    Keywords:  Antiviral; Envelope; Inactivation; Pseudorabies virus; Salvianolic acid A
    DOI:  https://doi.org/10.1016/j.phymed.2024.156015
  2. Int J Biol Macromol. 2024 Sep 10. pii: S0141-8130(24)06195-6. [Epub ahead of print] 135387
      The Human Respiratory Syncytial Virus (RSV) is the leading cause of acute respiratory infections in children. Currently, no safe, effective, or feasible option for pharmacological management of RSV exists. Hence, plant-derived natural compounds have been explored as promising antiviral agents. Mangifera indica is a globally distributed plant with reported anti-inflammatory, cardioprotective, and antiviral activities. Our study investigated the antiviral potential of a novel pectin from M. indica peels (PMi) and its chemically sulfated derivative (PSMi) against RSV in HEp-2 cells. The compounds were characterized using Fourier-transform infrared spectroscopy and nuclear magnetic resonance (NMR). NMR analysis revealed the presence of ester and carboxylic acid groups in PMi, and sulfation resulted in a sulfation degree of 0.5. PMi and PSMi showed no cytotoxic effects even at concentrations as high as 2000 μg/mL. PSMi completely inhibited RSV infectivity (100-1.56 μg/mL, 50 % inhibitory concentration of viral infectivity = 0.77 ± 0.11 μg/mL). The mechanism of action was investigated using the 50 % tissue culture infectious dose assay. PSMi displayed virucidal activity at concentrations from 100 to 6.25 μg/mL, and a significant reduction in viral infection was observed at all treatment times. Overall, PSMi is antiviral, cell-safe, and exhibits promising potential as an RSV treatment.
    Keywords:  Respiratory infection; Ribavirin; Sulfated polysaccharide
    DOI:  https://doi.org/10.1016/j.ijbiomac.2024.135387