[Effect of paeoniflorin on hepatic immunopathogenesis in mice with Schistosoma japonicum infection].

OBJECTIVE: To investigate the mechanism of paeoniflorin in preventing hepatic granuloma formation and fibrosis in mice infected with Schistosoma japonicum. METHODS: Model of hepatic granuloma and fibrosis was established by infecting mice with S. japonicum cercariae. The infected mice were randomly divided into 4 groups: group A as model (infected control) group (15 mice), and paeoniflorin being given before, simultaneously and after praziquantel treatment as groups B, C and D. Each of the groups B, C and D was subdivided into 3 subgroups (15 mice each): low dose (paeoniflorin 2 ml, 30 mg/(kg x d) x 30 d), high dose(paeoniflorin 2 ml, 120 mg/(kg x d) x 30 d) and control (2 ml, 0.5% sodium carboxymethylcellulose x 30 d). In group B, paeoniflorin or sodium carboxymethylcellulose was orally administrated on 12 d after infection. In groups C and D, paeoniflorin or sodium carboxymethylcellulose was administrated on 42 d or 72 d after infection. Each of group B, C and D was orally given praziquantel 2 ml (500 mg/(kg x d) x 2 d) on 42 d after infection. On the 102nd day after infection, all animals were sacrificed by cervical dislocation. Serum hyaluronic acid (HA) was detected by radioimmunoassay; area of egg granuloma and degree of hepatic fibrosis were observed via HE and Masson stainings; the expression of transforming growth factor beta1 (TGF-beta1), alpha smooth muscle actin (alpha-SMA and collagen I (Col I) protein were measured by immunohistochemical method. RESULTS: In group B, the level of HA (0.719 +/- 0.239 microg/ml, 0.721 +/- 0.182 microg/ml) in low or high dose subgroups was significantly lower (F = 9.429, P < 0.01) than the control subgroup (1.049 +/- 0.286 microg/ml); the area of granuloma (0.066 +/- 0.005 mm2, 0.064 +/- 0.004 mm2) or the degree of hepatic fibrosis (2.067 +/- 0.458, 1.967 +/- 0.399) in low or high dose subgroups was significantly greater (F = 862.540, F = 29.738, P < 0.01) than the control (0.141 +/- 0.008 mm2, 3.467 +/- 0.834); the expression of alpha-SMA positive cells (2.933 +/- 0.594, 3.000 +/- 0.535) in low or high dose subgroups was significantly lower (F = 12.323, P < 0.01, P < 0.01) than its control (4.800 +/- 1.859); the expression of TGF-beta1 (0.256 +/- 0.057, 0.274 +/- 0.054) in low or high dose subgroups was significantly lower (F = 148.990, P < 0.01) than its control (0.552 +/- 0.047); the content of Col I (0.334 +/- 0.041, 0.339 +/- 0.042) in low or high dose subgroups was significantly lower (F = 180.881, P < 0.01) than its control (0.601 +/- 0.049). In groups C & D, no significant difference was found between the low or high dose subgroups or between the subgroups and their corresponding controls. CONCLUSION: Paeoniflorin can significantly reduce hepatic granuloma formation and fibrosis due to schistosome eggs, and decrease the expression of TGF-beta1, alpha-SMA in mice when it is given before praziquantel administration, which may associate with the activation of hepatic stellate cells and the expression of TGF-beta1 in liver tissue.

[Effect of paeoniflorin on secretion of TGF-beta1 from macrophages in mice].

OBJECTIVE: To explore the effect of paeoniflorin (PAE) on the production of transforming growth factor beta1 (TGF-beta1) from peritoneal macrophages(PMs) stimulated by soluble egg antigen (SEA) of Schistosoma japonicum. METHODS: SEA was prepared by trituration and added into culture plank, flask and dish containing PMs which were cultured for 24 h. TGF-beta1 secreted from PMs was measured by ELISA. TGF-beta1 mRNA and protein produced from PMs were evaluated by RT-PCR and Western blotting, respectively. SEA (10 mg/L) 5 ml was added into culture flask and dish containing PMs. PMs were cultured for 12 h, and PAE at different concentrations (0, 7.5, 15, 30, 60, 120 mg/L) was added into the culture flask and dish, and PMs were cultured consecutively for another 12 h and 24 h, respectively. TGF-beta1 mRNA and protein from PMs stimulated by SEA were evaluated by RT-PCR and Western blotting, respectively. RESULTS: TGF-beta1 (235.86 +/- 3.43 ng/L) was produced from PMs under stimulation of SEA at 10 mg/L, and the expression of TGF-beta1 mRNA and protein in PMs were depressed significantly by PAE in a concentration-dependent manner (r = -0.827, P < 0.01; r = -0.952, P < 0.01, respectively). CONCLUSION: PAE inhibits the production of TGF-beta1 from PMs stimulated by SEA.