Antiviral effects of Phyllanthus urinaria containing corilagin against human enterovirus 71 and Coxsackievirus A16 in vitro

Human enterovirus 71 (EV71) and Coxsackievirus A16 (CA16) are major causative agents of hand, foot, and mouth disease (HFMD) especially in infants and children under 5 years of age. Despite recent outbreaks of HFMD, there are no approved therapeutics against EV71 and CA16 infection. Moreover, in a small percentage of cases, the disease progression can lead to serious complications of the central nervous system. In this study, we investigated the antiviral effect of corilagin and Phyllanthus urinaria extract, which contains corilagin as a major component, on EV71 and CA16 infection in vitro. Our results indicate that corilagin reduces the cytotoxicity induced by EV71 or CA16 on Vero cells with and IC₅₀ value of 5.6 and 32.33 μg/mL, respectively. We confirmed the presence of corilagin in EtOAc and BuOH fractions from P. urinaria extract and this correlated with antiviral activity of the fractions against EV71 or CA16. Future studies will be required to confirm the antiviral activity of corilagin and P. urinaria extract in vivo. Challenging a model with a lethal dose of viral infection will be required to test this. Collectively, our work provides potential candidates for the development of novel drugs to treat HFMD.