Identification of Cinobufagin and Resibufogenin as Inhibitors of Enterovirus 71 Infection

In this paper, cinobufagin and resibufogenin were found to inhibit enterovirus 71(EV71) infection in vitro in cell viability and plaque reduction assays. The 50% inhibitory concentrations(IC50) of cinobufagin and resibufogenin were (10.94±2.36) and (218±31) nmol/L, respectively, the 50% cytotoxic concentrations(CC50) of them were (1277±223) and (1385±254) nmol/L, respectively, and the anti-EV71 selectivity index(SI50) of cinobufagin was 116.7, which are promisingly developed into drug. Using a VP1 detection assay and a constructed reporter luciferase, we found that cinobufagin and resibufogenin disrupted the synthesis of EV71 protein. However, neither of them inhibited EV71 RNA replication. Our study suggests that cinobufagin and resibufogenin are the promising candidates that should be further investigated for the treatment of EV71 caused disease.