Effect of γ-Tocotrienol and α-Tocopherol on Blood Glutathione and Tumor Marker Enzymes during Chemical Hepatocarcinogenesis in the Rat

抄録

The protective effect of two types of vitamin E (α-tocopherol and γ-tocotrienol) in rats treated with diethylnitrosamine (DEN) and 2-acetylaminofluorene (AAF) were studied by determination of plasma alkaline phosphatase (ALP), plasma and liver microsomal γ-glutamyl transpeptidase (GGT) activities, and blood glutathione (GSH). Rats treated with DEN/AAF had significantly elevated plasma and microsomal GGT, plasma ALP activities, and blood GSH levels compared with the normal controls (p<0.05). Supplementation with vitamin E of normal controls did not affect the enzyme activities or blood GSH. In rats treated with DEN/AAF, vitamin E supplementation attenuated GGT and ALP activities and blood GSH levels. The optimum dose required for highest attenuation of the tumor marker enzyme activities was 34mg/kg diet for α-tocopherol and 30mg/kg diet for γ-tocotrienol. Higher doses of the vitamin did not show further attenuation in the level of the tumor marker enzyme activities.