Abstract: Objective To investigate the inhibition of primary cultured hepatic stellate cell （HSC） activation by phenylarsine oxide （PAO） in vitro. Methods Primary cultured HSCs were isolated from rat 1iver by Nycodenz density-gradient centrifugation. The morphological features of the cells were observed under inverted microscope. The cytotoxicity of PAO on HSCs-T6 was determined by MTT after treated with 5 different PAO concentrations（25,50,100,150 and 200 nmol/L） for 24 h. We chose proper concentration of PAO （<100 nmol/L） in this experiment,and then we divided primary cultured HSCs at day 4 into four groups receiving PAO at concentration of 0,25,50 and 100 nmol/L respectively. The expressions of α-SMA and type I collagen were measured by Western blot and Real-time PCR respectively. Results Expression of α-SMA was up-regulated as HSCs activation at primary culture （the expression of α-SMA increased significantly at day 4 （1.51±0.045） as compared with at day 1[（0.762±0.062）,P<0.05】; PAO at 25 to 100 nmol/L concentration range had no obvious cytotoxicity to activated HSCs,and down-regulated and inhibited α-SMA mRNA and collagen type I mRNA levels and their protein expression of HSCs in a concentration-dependent manner. Conclusion The HSCs is initially activated at day four in vitro culture,and PAO at 25 to 100 nmol/L range can inhibit the spontaneous activation of HSCs in vitro.

Key words: Hepatic fibrosis, Hepatic stellate cells, Phenylarsine oxide, In vitro