Inhibitory Effect of Baicalin on 2019-NCOV Invasion

Objective To study the the inhibitory effect of baicalin on novel Coronavirus (2019-NCOV) entry process in vitro. Methods The pseudovirus system of SARS-CoV-2 S protein constructed with luciferase reporter gene was used in the study. A luciferase kit was used to detect the changes of luciferase expression in Huh-7 cells, and then the virus inhibition curve was plotted. Results Baicalin can significantly inhibited the infection rate of pseudovirus. There was no significant difference in the virus inhibition curve between the baicalin&virus pre-incubation group and co-incubation at different concentrations, indicating that baicalin could not directly bind to virus, but inhibited the virus S protein mediated cell fusion process. We futher found that, the inhibition rate of baicalin to virus decreased significantly in the 4h group, but had no significant difference in the 0h and 2h groups at the concentration of 0.125mg/ mL, indicating that baicalin may have an inhibitory effect on virus invasion stage rather than adsorption stage, and the mediated inhibition stage occurred within 4h. Conclusion Baicalin may mediate the fusion of SARS-CoV-2 S protein with cell surface receptor and exert anti-novel coronavirus activity by playing a role in inhibitting virus invasion in non-adsorption stage.