Anti-HBV Activities of Xanthones From Swertia Punicea Hemsl

Abstract

We studied the effects of two xanthones compounds isolated from Swertia punicea Hemsl (from Geutianaceae), swertianolin (I) and bellidifolin (II), on Hepatitis B surface antigen (HBsAg) and e antigen (HBeAg) in cultured human hepatocellular carcinoma cell line (HepG₂). The HepG₂ cells were first cultured for 24h, various concentrations of these two xanthones were then added to the culture medium. The culture medium containing the two xanthones was exchanged once every 4 days. After 8 days, the cytotoxic activities of these two xanthones were assessed by cytopathic effect. The HepG₂ cells were then treated with the two compounds at a concentration of swertianolin (1.6, 3.1, 6.2, 12.5, 25mg/ml) and bellidifolin (2.0, 3.9, 7.8, 25.5, 31.2mg/ml). Four or eight days later, the culture medium was collected and the expression of HBsAg and HBeAg were determined by radioimmunoassay. Our results show that swertianolin can suppress the expression of HBeAg with IC₅₀ of 8.0mg/ml, while bellidifolin can inhibit the expression of HBsAg with IC₅₀ of 13mg/ml at the eighth days. The Therapeutic Index for swertianolin and bellidifolin are 6.2 and 6.8, respectively. Our findings suggest that swertianolin and bellidifolin have anti-HBV activities in vitro.