A water extract of Pueraria lobata inhibited cytotoxicity of enterovirus 71 in a human foreskin fibroblast cell line.

Enterovirus 71 (EV71) can cause brain encephalitis and mortality. However, effective vaccines or chemotherapeutic agents are not yet available. We tested the hypothesis that Pueraria lobata could inhibit the cytotoxic effect of EV71 in a human foreskin fibroblast cell line by the XTT method. Our results showed that the water extract of P. lobata could inhibit cytopathy induced by EV71 when given before (p < 0.0001), simultaneously with (p < 0.0001), or after viral infection (p < 0.0001). Water extract of P. lobata was effective and its minimal concentration that inhibited 50% of the cytopathic effect (IC50) was 0.028 microg/mL. P. lobata was also safe with a selectivity index greater than 107,000. Water extract of P. lobata appeared to inhibit viral attachment (p < 0.0001) and penetration (p < 0.0001). The anti-EV71 activity of the water extract of P. lobata was not mediated by interferons. In conclusion, the water extract of P. lobata was effective in the management of the disease induced by EV71 infection.