Abstract

To study anti-hepatitis effect of isochlorogenic acid C from Laggera alata, anti-apoptotic and anti-injury properties of test compound were evaluated using the d-galactosamine (d-GalN)-induced apoptosis/injury model in human hepatocyte line HL-7702 cells. Hepatocyte apoptotic changes were demonstrated by DNA ladder analysis and caspase-3 activation. Hepatocyte injury was assessed by cell viability. Meanwhile, anti-hepatitis B virus (anti-HBV) effect of test compound was evaluated by the HBsAg, HBeAg, HBV DNA, HBV covalently closed circular DNA (HBV cccDNA) and heme oxygenase-1 (HO-1) expressions in HBV-transfected HepG2.2.15 cells. The results showed that test compound at concentrations of 10 to 100 µg/ml significantly reduced the caspase-3 and transformed growth factor β1 (TGFβ1) levels of the d-GalN-challenged hepatocytes. Also, test compound improved markedly cell viability of the d-GalN-injured hepatocytes and produced a maximum protection rate of 47.28% at a concentration of 100 μg/ml. Furthermore, test compound significantly inhibited productions of HBsAg and HBeAg. Its maximum inhibitory rates on the HBsAg and HBeAg expressions were 86.93 and 59.79%, respectively. In addition, test compound significantly induced the HO-1 expression of HepG2.2.15 cells. This study verifies that isochlorogenic acid C possesses potent hepatoprotective and anti-HBV effects. The anti-apoptotic and anti-injury effects of test compound could be achieved by its anti-oxidative properties and interfering the caspase-3 and TGF-β1 expressions. The anti-HBV target of test compound may mainly be at the downstream links of HBV replication process and is probably associated with blocking translation step. Furthermore, HO-1 induction may contribute to anti-hepatitis B effect of test compound.

Key words: Laggera alata, isochlorogenic acid C, d-Galactosamine, anti-hepatitis B, covalently closed circular DNA, heme oxygenase-1.