Antiviral activity of the dichloromethane extracts from Artocarpus heterophyllus leaves against hepatitis C virus

Objective To determine anti-viral activities of three Artocarpus species: Artocarpus altilis, Artocarpus camansi, and Artocarpus heterophyllus (A. heterophyllus) against Hepatitis C Virus (HCV). Methods Antiviral activities of the crude extracts were examined by cell culture method using Huh7it-1 cells and HCV genotype 2a strain JFH1. The mode of action for anti-HCV activities was determined by time-of-addition experiments. The effect on HCV RNA replication and HCV accumulation in cells were analyzed by quantitative reverse transcription-PCR and western blotting, respectively. Results The dichloromethane (DCM) extract of A. heterophyllus exhibited strong anti-HCV activity with an inhibitory concentration (IC₅₀) value of (1.5 ± 0.6) μg/mL without obvious toxicity. The DCM extracts from Artocarpus altilis and Artocarpus camansi showed moderate anti-HCV activities with IC₅₀ values being (6.5 ± 0.3) μg/mL and (9.7 ± 1.1) μg/mL, respectively. A time-of-addition studies showed that DCM extract from A. heterophyllus inhibited viral entry process though a direct virucidal activity and targeting host cells. HCV RNA replication and HCV protein expression were slightly reduced by the DCM treatment at high concentration. Conclusions The DCM extract from A. heterophyllus is a good candidate to develop an antiviral agent to prevent HCV grant reinfection following liver transplantation.