Abstract

Enterovirus 71 (EV71) infection caused host immune responses and resulted in severepathogenicity. In this study, a preliminary anti-EV71 activity of 58 Taiwanese folk medicinal plants and further investigations of the anti-EV71 activity and immunomodulatory effect ofAmpelopsis brevipedunculata (Maxim.) Trautv (ABT) were performed. Of the 58 plant extracts, 37 extracts exhibited anti-EV71 activity and strong activity was demonstrated by six extracts with average 50% inhibitory concentrations (IC₅₀) below 80 μg/ml. The ABT (one of the most effective plants) acetone extract exhibited relatively high anti-EV71 activity with 26.11 μg/ml of average IC₅₀, 3.6% of that of the positive control (ribavirin, 734.52 μg/ml). The anti-EV71 modes of the ABT extract included viral infection prevention, viral inactivation and anti-viral replication. Acidic pH treatments slightly decreased anti-EV71 activity of the extract. The ABT extract significantly increased the interlukin-6 (IL-6) and IL-1β and decreased the IL-8 levels in the EV71-infected cells. In summary, a high rate of the screened plants exhibited anti-EV71 activity and the greatest activity was demonstrated by ABT. High amounts of IL-6 induction in the infected-cells had high correlation with the anti-viral replication of the ABT extract.

Key words: Antienterovirus 71 activity, Ampelopsis brevipedunculata (Maxim.) Trautv, immune modulation, medicinal plant.