Inhibition of subgenomic hepatitis C virus RNA transcription by chinese herbal extracts

Hepatitis C virus (HCV) causes chronic hepatitis, cirrhosis and hepatocellular carcinoma. Some patients are resistant to interferon-α (IFN-α) treatment, and thus there is urgent need to improve anti-HCV therapies and discover novel therapeutic approaches in the form of new antiviral agents. Using real-time PCR (RT-PCR) and the MTS assay, we examined the suppression of HCV replication and the cytotoxicity of 11 aqueous extracts and eight compounds using Chinese herbs traditionally used for liver protection. Curcuma aromatica Salisb. (Zingiberaceae), Canna indica L. (Cannaceae), and two commercial extracts from Ganoderma tsugae Murr. (Aphyllophoromycetideae), Triterpenoids Enterprise (Shuang Hor Lingzhi ®) and Polysaccharides Enterprise (Shuang Hor Supreme Lingzhi ®) substantially inhibited HCV replication at 1 mg/ml in Huh-7 human hepatoma cells containing an HCV subgenomic replicon. In addition, HCV-Huh-7 cells treated with a combination of a low dose (10 IU/ml) of IFN-α and 1 mg/ml of one of the four herbal extracts also exhibited significant inhibition of HCV replication. Thus, C. aromatica, C. indica, Triterpenoids Enterprise (Shuang Hor Lingzhi ®), and Polysaccharides Enterprise (Shuang Hor Supreme Lingzhi ®) are possible sources of potent anti-HCV agents.