Anti-hepatitis B Virus Activities of Cinobufacini and Its Active Components Bufalin and Cinobufagin in HepG2.2.15 Cells

Cinobufacini (Huachansu) is a Chinese medicine prepared from the skin of Bufo bufo gargarizans Cantor (Bufonidae), which has long been used in traditional Chinese medicine (TCM). The aim of present study was to examine the anti-hepatitis B virus (HBV) activities of cinobufacini and its active components bufalin and cinobufagin in the human HBV-transfected cell line HepG2.2.15. The hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and hepatitis B core-related antigen (HBcrAg) concentrations in cell culture medium were determined by chemiluminescent enzyme immunoassay after HepG2.2.15 cells were respectively treated with different concentrations of cinobufacini, bufalin, and cinobufagin for 3 or 6d. HBV DNA and mRNA were determined using transcription-mediated amplification and real-time polymerase chain reaction (PCR), respectively. On d 3, cinobufacini at a concentration of 1 mu g/ml had no activity against HBV virological markers. However, on d 6, cinobufacini at 1 mu g/ml effectively inhibited the secretion of HBsAg, HBeAg, and HBcrAg by 29.58, 32.87, and 42.52%. It was more potent than the positive control lamivudine (100 mu g/ml). Bufalin and cinobufagin slightly inhibited HBV antigen secretion. Treatment with cinobufacini, bufalin, or cinobufagin had no anti-HBV effect on DNA in cell culture medium. Consistent with the HBV antigen reduction, HBV mRNA expression was markedly inhibited in comparison to the control when HepG2.2.15 cells were treated with cinobufacini, bufalin, or cinobufagin. Results suggested that cinobufacini had more potent activity against HBV antigen secretion than its components bufalin and cinobufagin and this inhibitory role was attributed to the specific inhibition of HBV mRNA expression.