Soybean extract inhibits influenza virus entry: Mechanistic insights

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.