Abstract: Objective To study the expression of hepatic Bcl-2 and Bax proteins in mice infected with Schistosoma japonicum and the role of pentoxifylline (PTX) in the expression. Methods Forty mice were randomly divided into 4 groups: one normal control group，mice in the other three groups were all infected each with 25 cercariae, the infected control group was fed for 10 weeks after infection， and 2 weeks after infection, the high dose PTX group was given PTX 360 mg/（kg·d） for 8 weeks and the low dose PTX group was given PTX 180 mg/（kg·d）also for 8 weeks. At the end of 10 weeks all the mice were killed. Bcl-2 and Bax proteins expression was detected by immunohistochemisty. Results Compared with the normal control group， the expression of Bcl-2 and Bax was significantly higher in the infected control group (P﹤0.05). Bcl-2 was significantly higher in high dose PTX group than in the infected control group and in low dose PTX group (P﹤0.05). However there was no significant difference in the expression of Bax among the groups (P﹥0.05). Conclusion PTX treatment can significantly increase the expression of Bcl-2 in liver tissue of schistosome-infected mice in a dose-dependent manner， and may play a role against liver inflammation and schistosomiasis-related liver fibrosis.

Key words: Schistosoma japonicum, Bcl-2, Bax, Pentoxifylline(PTX)