[Influence of kaempferol on TGF-β1/Smads signal path in liver tissue of mice with Schistosoma japonicum infection].

OBJECTIVE

To investigate the influence of kaempferol on transforming growth factor(TGF-β1/Smads signal tiransduction in liver tissue of mice with schistosomiasis liver fibrosis.

METHODS

Forty BALB/c mice were randomly divided into a normal control group (8 mice), a praziquantel group (8 mice ), and 4 praziquantel + kaempferol groups with different kaempferol dosages (5, 10, 15, 20 mg/kg respectively, 6 mice each group). Besides the normal control group, all the mice in the other 5 groups were infected with Schistosoma japonicum. After the infection for 6 weeks, the praziquantel group and the 4 praziquantel + kaempferol groups were treated with praziquantel 500 mg/(kg.d) for 2 d, then the mice in the praziquantel group were drenched with normal saline for 6 weeks, and those in the 4 praziquantel + kaempferol groups were drenched with kaempferol 5, 10, 15, 20 mg/kg respectively for 6 weeks. After the treatment, all the animals were sacrificed by the cervical dislocation method, and the area of egg granuloma and the degree of fibrosis in the livers of the mice were observed by HE and Masson staining. The expressions of TGF-β1, Smad2/3, Smad7 proteins were measured by the immunohistochemical method, and the mRNA levels of the 3 proteins were detected by RT-PCR.

RESULTS

Compared with the mice in the praziquantel group, the areas of egg granuloma of the liver of the mice in the 4 praziquantel + kaempferol groups were smaller, and the degrees of the hepatic fibrosis of the mice were lesser, and their expressions of Smad2 and Smad3 at protein and their mRNA levels were significantly lower (all P < 0.05), while the expression of Smad7 at protein and its mRNA level were significantly higher (all P < 0.05).

CONCLUSION

By decreasing the expressions of TGF-β1 and Smad2/3, and increasing the expression of Smad7, kaempferol can significantly reduce the degrees of hepatic fibrosis and granuloma caused by schistosome eggs after the praziquantel treatment.