Abstract
Vigna radiata (L.) R. Wilczek (mung bean) is a Chinese functional food with antioxidant, antimicrobial and anti-inflammatory activities. However, little is known about its antiviral activity. We aimed to investigate the antiviral activity and mechanisms of action of Vigna radiata extract (VRE) against influenza virus. HPLC was conducted to analyze the components of the VRE. The anti-influenza viral activity of VRE in Mardin-Darby canine kidney (MDCK) cells was evaluated by virus titration assays, hemagglutination assays, quantitative RT-PCR assays, cellular α-glucosidase activity assays and neuraminidase activity assays. Chromatographic profiling analysis identified two major flavonoids, vitexin and isovitexin, in the ethanol extract of Vigna radiata. Through in vitro studies, we showed that VRE, at concentrations up to 2,000 μg/ml, exhibited no cytotoxicity in MDCK cells. VRE protected cells from influenza virus-induced cytopathic effects and significantly inhibited viral replication in a concentration-dependent manner. A detailed time-of-addition assay revealed that VRE may act on both the early and late stages of the viral life cycle. We demonstrated that 1) VRE inhibits virus entry by directly blocking the HA protein of influenza virus; 2) VRE inhibits virus entry by directly binding to cellular receptors; 3) VRE inhibits virus penetration; 4) VRE inhibits virus assembly by blocking cellular α-glucosidase activity, thus reducing HA protein trafficking to the cell surface; and 5) VRE inhibits virus release by inhibiting viral neuraminidase activity. In summary, Vigna radiata extract potently interferes with two different subtypes of influenza viruses at multiple steps during the infectious cycle, demonstrating its broad-spectrum potential as an anti-influenza preventive and therapeutic agent. Continued development of Vigna radiata-derived products into antiviral therapeutics is warranted.
Highlights
Influenza A virus infection is a zoonotic infectious disease that continues to pose a pandemic threat worldwide
The Vigna radiata extract (VRE)- and virus-containing medium was changed to fresh medium, and the cells were incubated for an additional 11 h. 3) For the “pretreated cell + wash” group, Mardin-Darby canine kidney (MDCK) cells were incubated with VRE for 1 h, FIGURE 1 | Representative HPLC chromatograms from the seed coats of Vigna radiata (L.) R
The results showed that VRE exhibited no cytotoxicity in MDCK cells, even at 2,000 μg/ml, the highest concentration used in this study (Figure 2A)
Summary
Influenza A virus infection is a zoonotic infectious disease that continues to pose a pandemic threat worldwide. Influenza A virus contains eight negative-sense single-stranded viral RNA (vRNA) segments, encoding for more than 10 viral proteins. Vigna radiata Counteracts Influenza Virus hemagglutinin (HA) interacts with the host cell receptor, and the neuraminidase (NA) plays a role in viral release. Polymerase basic protein 1 and 2 (PB1, PB2), polymerase acidic protein (PA) and nucleoprotein (NP) are members of the viral ribonucleoprotein (vRNP), responsible for vRNA replication. The influenza A virus life cycle begins with the attachment between viral HA protein and host sialic acid. The newly synthesized RNA is transported back to the cytosol for viral protein translation. After post-translational glycosylation of viral HA and NA, these proteins traffic to the cell membrane together with newly synthesized vRNP to form viral particles. The viral NA with sialidase activity cuts the linkage of viral HA and host sialic acid, leading to the release of viral particles (Dou et al, 2018)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
