Protective Effect Of Vitamin E On Liver Toxicity Of Benzo [a] Pyrene Induced In Male Rats

ObjectiveTo study toxic effects of benzo[a]pyrene exposure on the liver tissue of male rats in 30 days and protective effect of different doses of vitamin E on liver toxicity induced by benzo[a]pyrene. To explore the possible mechanism of vitamin E antagonistic benzo[a]pyrene on liver toxicity.MethodThe 3 weeks old SPF SD rats were randomly divided into six groups of 10, which were as follows:control group (double distilled water), solvent control group (vegetable oil), B[a]P group (5mg/kg B[a]P), B[a]P plus low-dose VE group (5mg/kg B[a]P+10mg/kg VE), B[a]P plus mid-dose VE group (5mg/kg B [a] P+50mg/kg VE), B[a]P plus high-dose VE group (5mg/kg B[a]P+100mg/kg VE). After intragastric administration applied for 30 days, blood and liver tissue were collected and the liver indices were measured.The liver histopathlogies were observed by HE staining. Serum was isolated for measurement of ALT and AST activity. The homogenate of Liver tissue was prepared to measure SOD, GSH-PX activity and MDA,8-OHdG, TNF-acontents.ResultsFor liver indices, there was increased significantly (P<0.05) in B[a]P group compared with the control group, there was not statistically significant difference(P> 0.05) between low-dose VE+B[a]P group and B[a]P and there was statistically significant in mid-dose VE+B[a]P group, high-dose VE+B[a]P group compared with B[a]P group.HE staining results:there were significant liver damage in B[a]P group. The structure of hepatic lobules in B[a]P group was not clear and the liver cell was focal necrosis and swelling. The degree of liver injury was significant reduced in the treatment group with VE and there was more obvious improvement with the dose increasing of VE.For the level of AST, there was significantly increasing in B[a]P group, low-VE+B[a]P group, mid-VE+B[a]P group compared with the control group, there was statistical difference(P<0.05) between high-VE+B[a]P group and B[a]P group. The level of ALT in B[a]P group was obviously higher than in control group and the level of ALT in low-VE+B[a]P group, mid-VE+B[a]P group and high-VE+B[a]P group higher than in control group. There was statistically significant in high-VE+B[a]P group compared with B[a]P group(P<0.05).Comparing with the control group, there were the increasing of MDA and the significant reduction of SOD and GSH-PX of liver in B[a]P groups(P<0.05). Comparing with B[a]P group, there were not obvious improvement of MDA and GSH-PX in low-VE+B[a]P group and mid-VE+B[a]P group, which was higher activity of SOD. The content of MDA was reduced in high-VE+B[a]P group, while the activity of SOD and GSH-PX was increased Compared with B[a]P group.There was significantly increasing of the 8-OHdG content in B[a]P group compared with the control group. There was reduction of the 8-OHdG content in low-VE+B[a]P group, mid-VE+B[a]P group,high-VE+B[a]P group compared with B[a]P group, in which there was lower with the dose add of VE.Compared with the control group, there was significantly increasing of TNF-ain B[a]P group and low-VE+B[a]P group(P<0.05),which was not significant difference in middle and high vitamin E+B[a]P group. Compared with the B[a]P group, there was significantly decreasing of TNF-ain middle and high VE+B[a]P group(P<0.05) and was not significant difference of TNF-α in low vitamin E+B[a]P group.ConclusionExposure to B[a]P in 30 days can cause liver histopathological changes, increase of ALT and AST activity in serum,increase of MDA,TNF-aand 8-OHdG content in liver, decrease of SOD and GSH-PX level in liver, liver function damage in male rats. Appropriate doses of VE can antagonize this toxic effect.