[Preliminary screening of activity fraction of Alchornea trewioides suppresses expression of subgenomic hepatitis C virus RNA in vitro].

Objective: To screen activity fraction of Alchornea trewioides which suppresses expression of subgenomic Hepatitis C Virus (HCV) RNA in vitro.

Methods: Anti-HCV effects in vitro were examined in an HCV subgenomic replicon cell culture system--CBRH7919 (Jneo3-5B). The cells were exposed to different concentrations of A. trewioides initial ethanol extracts, portions of petroleum ether,ethyl acetate and n-butanol extracts with interferon a combined with ribavirin as positive control. The content of HCV RNA was examined by Quantitative PCR. The expression levels of functional proteins NS3 were examined in all groups by Western blot. Cell proliferation test with CCK-8 assay was used to evaluate the cytotoxicity of drugs.

Results: The study showed that exposure of CBRH7919 (Jneo3-5B) cells to ethyl acetate extract of A. trewioides resulted in a concentration-dependent inhibition of subgenomic HCV RNA replication and NS3 protein expression ability among the four extracts (P < 0.05). The activity of ethyl acetate extract was increased by 5.71 times than that of the initial ethanol extract. IC50 to subgenomic HCV RNA was 14.60 mg/L, CC50 to CBRH7919 (Jneo3-5B) cells was 40.30 mg/L and the treatment index (TI) was 2. 76.

Conclusion: The ethyl acetate extract of A. trewioides is the activity fraction which can significantly interfere with subgenomic HCV RNA replication and expression of NS3 protein in vitro. These data suggest that ethyl acetate extract isolated from A. trewioides may have potential use as an anti-HCV compound.