Anti-hepatitis B virus activity of total saponins isolated from Taraphochlamys affinis in vitro and in vivo

Abstract

Taraphochlamys affinis have been previously shown to possess anti-hepatitis B virus (HBV) activities. To identify the active ingredients, we isolated total saponins (TSTA) from the dried herb of T. affinis and examined the inhibitory effect of TSTA on HBV in vitro and in vivo. In human liver cell line HepG2.2.15 transected with HBV, the TC50 of TSTA was 358.6 mg/ml and TC0 was 77.6 mg/ml, which suggested that the inhibitory action of TSTA had no cytotoxicity. In nontoxic concentrations, TSTA effectively suppressed the secretion of HBV antigens from virus-infected HepG2.2.15 cells, achieving 77.2, 60.4, 55.3, 44.9 and 26.2% inhibition to the secretion of HBsAg, and 43.2, 26.5, 11.9, 2.5 and 19.2% inhibition to that of HBeAg, respectively, at 50, 25, 12.5, 6.25 and 3.125 mg/ml after 72 h of treatment. HBsAg and HBeAg values of treatment index (TI) were 33.6 and 4.1, respectively indicating that TSTA was effective and low in toxicity. In treatment of ducklings infected with duck hepatitis B virus (DHBV), the serum levels of DHBV-deoxyribonucleic acid (DNA) decreased in all 10 ducks treated with two doses of TSTA (1.0 and 2.0 g kg-1 d-1), respectively seven days after the cessation of treatment with TSTA, the effect of DHBV DNA inhibition persisted. Histopathological examination also confirmed the protective function of TSTA in the liver infected with DHBV. Together, our results demonstrate that TSTA possesses potent anti-HBV activity. Keys words: Taraphochlamys affinis; the total saponins of Taraphochlamys affinis (TSTA), anti-hepatitis B virus activity.