The inhibitory actions of houttuynia cordata aqueous extract on dengue virus and dengue-infected cells

Abstract

The antiviral activities of Houttuynia cordata (H.cordata) aqueous extract against dengue virus serotype 2 (DEN-2), strain 16681, were evaluated in this study. The results showed that pre- and post-incubation of H.cordata extract (10-100μg/mL) with HepG2 cells significantly reduced intracellular DEN-2 RNA production correlating with the decrease in dengue protein expression. In the direct blocking mode, the extract bound with DEN-2 and strongly inhibited the intracellular viral RNA replication with an effective dose (EC 50 ) of 0.8μg/mL. Concentrations as low as 10-40μg/mL of H.cordata extract also exhibited protective effect on virion release from infected LLC-MK 2 cells. High-performance liquid chromatography analysis of H.cordata extract indicated that hyperoside was the predominant bioactive compound, and was likely to play a role in this inhibition. The extract was also shown to have no genotoxic effect on human blood cells. © 2011 Wiley Periodicals, Inc.