Objective: The aim of this study was to examine extracts from Indonesian plants to identify a compound(s) responsible for antiviral activity against hepatitis C virus (HCV). Methods: Huh7it-1 cells, a clone of human hepatocellular carcinoma-derived Huh7 cells, were infected with the HCV genotype 2a strain JFH1 in the presence of crude methanol extracts from the plants. The extracts were further fractionated and purified by anti-HCV bioactivity-guided analysis using a combination of various column chromatography techniques. The isolated compounds were examined for anti-HCV activity and cytotoxicity, and their structures determined by nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry. Results: Screening of Indonesian plants revealed that a crude methanol extract from Kalanchoe pinnata exhibited anti-HCV activity with a 50%-inhibitory concentration (IC50) of 17.2 μg/ml. An ethyl acetate fraction was found to possess strong anti-HCV activity, from which three compounds, i.e., quercetin, gallic acid and quercitrin, were isolated. Anti-HCV activity assay revealed that quercetin and gallic acid, but not quercitrin, inhibited HCV production in a dose-dependent manner, with IC50 values of 1.5 and 6.1 μg/ml, respectively, without exhibiting cytotoxicity. A time-of-addition study demonstrated that quercetin acted at the post-entry step whereas gallic acid at both the entry and post-entry steps. Conclusion: An extract from K. pinnata and its constituents, quercetin and gallic acid, could be potentially used as a supplement for the treatment of HCV infection.
|Number of pages||5|
|Journal||International Journal of Pharmacy and Pharmaceutical Sciences|
|Publication status||Published - 1 Jan 2014|
- Hepatitis C virus
- Herbal plant
- Kalanchoe pinnata