Aims: The anti-enterovirus 71 (EV71) activity of six Nepalese plants' extracts and gallic acid (GA) isolated from Woodfordia fruticosa Kurz (family; Lythaceae) flowers were evaluated in Vero cells.
Methods and results: The anti-EV71 activity of tested compounds was evaluated by a cytopathic effect reduction method. Our results demonstrated that flowers' extracts of W. fruticosa exerted strong anti-EV71 activity, with a 50% inhibitory concentration (IC(50)) of 1.2 microg ml(-1) and no cytotoxicity at a concentration of 100 microg ml(-1), and the derived therapeutic index (TI) was more than 83.33. Rivabirin showed no antiviral activity against EV71. Furthermore, GA isolated from W. fruticosa flowers exhibited a higher anti-EV71 activity than the extract of W. fruticosa flowers, with an IC(50) of 0.76 microg ml(-1) and no cytotoxicity at a concentration of 100 microg ml(-1), and the derived TI was 99.57.
Conclusions: This study demonstrated that flower extracts of W. fruticosa possessed anti-EV71 activity and GA isolated from these flowers showed stronger anti-EV71 activity than that the extracts.
Significance and impact of the study: Our results suggest that the GA from W. fruticosa flowers may be used as a potential antiviral agent.