Influences of plumbagin on phosphatidylinositol 3-kinase/protein kinase B signaling pathway in rats with hepatic fibrosis / 中华传染病杂志

ABSTRACT

Objective To explore the influences of plumbagin on phosphatidylinositol 3-kinase (PI3K)/ protein kinase B (Akt) signaling pathway in rats with carbon tetrachloride induced liver fibrosis.Methods Forty male SD rats were assigned to control group,model group,2 mg/kg plumbagin treated group and 3 mg/kg plumbagin treated group,with 10 rats in each group.Rats of the control group were injected with 0.9％ NaCl solution (2 mL/kg) intraperitoneally,while rats of the other three groups were injected with 60％ carbon tetrachloride/peanut oil (2 mL/kg,3 times a week for 6 weeks) intraperitoneally.Since the third week after modeling,rats of plumbagin treated groups were treated with intraperitoneal injection of plumbagin at a dose of 2 mg/kg and 3 mg/kg (twice a week for 4 weeks),respectively.Serum levels of alanine aminotransferase (ALT),aspartate aminotransferase (AST),albumin (Alb) were monitored routinely.Hyaluronic acid (HA) and laminin (LN) were measured by radioimmunoassay after 6 weeks; protein expression of liver PI3K,Akt and phosphorylated Akt (p-Akt) were evaluated by Western blotting and immunohistochemistry,respectively.Comparison of means among groups was performed by univariate analysis of variance.Results The hepatic fibrosis model was successfully established after 6 weeks.Serum levels of ALT,AST,HA and LN of model group were significantly higher than those of control group (all P＜0.05).Serum levels of ALT,AST,HA and LN of 2 mg/kg plumbagin treated group and 3 mg/kg plumbagin treated group were significantly lower than those of model group,and the differences were statistically significant (all P＜0.05).The protein expressions of PI3K and Akt in each group were comparable (all P＞0.05).The p-Akt protein was mainly expressed in nucleus of hepatocytes.The levels of p-Akt protein in control group,model group,2 mg/kg plumbagin treated group and 3 mg/kg plumbagin treated group were 0.0821±0.0003,0.7374±0.0037,0.3679 ±0.0332 and 0.1327±0.0561,respectively,and that in model group was significantly higher than control group (t =851.302,P＜0.05),but those in plumbagin treated groups were both lower than model group (t=71.858 and 28.363,all P＜0.05).Conclusions Plumbagin presents anti-fibrotic effects in the liver,by down-regulating the expression of p-Akt during the development of fibrosis,which might be one of the antifibrotic mechanisms.