Study on the Chemical Constituents and anti-HBV Activity of Hypericum japonica

The most common cause of chronic viral hepatitis worldwide is from the Hepatitis B virus (HBV). Screening the safe and effective anti-HBV compounds in traditional Chinese medicine provides a large opportunity for the development of anti-HBV drugs. We found the ethanol extract of H. japonica had the besr inhibitory effects on HBeAg secretion from 20 species of medicinal plants In this study, silica gelSephadex LH-20. and a thin layer of chromatography were used to screen and isolate active anti-hepatitis B virus compounds from Hypericum japonica that was extracted with 60% ethanol. Four compounds were separated from the ethyl acetate extract of II center dot japonica and their structures were identified by spectral chemical and structural analyses. In addition, using HepG2 2.2.15 cell line with the cytotoxicity and inhibitory effecting on the secretion of HBeAg and HBsAg of the 4 isolated compounds were examined by MTT and enzyme-linked immunosorbent assays. The four isolated compounds were determined and 1,3,6,7-tetrahydroxy-9H-xanthen-9-one (Compound 4) exhibited the highest activity in inhibiting secretion of HBeAg in HepG2 2.2.15cells. The results indicated a 67.66% of inhibition rate, 40.25 mu g /mL of IC50 value and TI > 2. We conducted a qualitatively evaluated research using duck hepatitis B virus model in vivo, the results indicated that ethanol extracts of H. japonica had anti-HBV effects and almost no sign of disease rebound after drug withdrawing. But the compound 4 has no direct inhibitory effect on HBV-DNA in duck experiment.