Objective: To observe the effects of paeoniflorin on the expressions of CTGF and PDGF in liver tissue of fibrosis and the serum level of TNF-alpha in mice infected with Schistosoma japonicum, and to explore the protective effect and its mechanisms of paeoniflorin on liver fibrosis.
Methods: Kunming mice were divided randomly into 5 groups, namely normal control group (Group A), paeoniflorin groups (Group B, C, D) and infected control group (Group E). The mice in Group B-E were infected with cercariae of Schistosoma japonicum, and then they were treated with praziquantel (400 mg/kg per day) for 2 days after 6 weeks. After that, the mice in Group B, C, D were given paeoniflorin with a dose of 30, 60, 120 mg/(kg x d), respectively. After 8 weeks of paeoniflorin treatment, all the mice were killed, and their livers and serum were obtained. Hematoxylin and eosin stain and Masson stain were used to observe the degree of hepatic fibrosis. Immunohistochemical staining was performed to detect the expressions of CTGF and PDGF in liver tissue. The serum level of TNF-alpha was detected by ELISA.
Results: The expression levels of CTGF and PDGF proteins in liver tissue and the serum level of TNF-alpha of the mice in the high dosage paeoniflorin treatment group (Group D) were significantly lower than those in the infected control group (P < 0.05).
Conclusions: The effects of paeoniflorin on hepatic fibrosis induced by Schistosoma japonicum infection depends on its dosage. Paeoniflorin may exert its effects by inhibiting the serum level of TNF-alpha and down regulating the expression of CTGF and PDGF proteins.