EFFECT OF GAMMA-TOCOTRIENOL AND ALPHA-TOCOPHEROL ON BLOOD GLUTATHIONEAND TUMOR-MARKER ENZYMES DURING CHEMICAL HEPATOCARCINOGENESIS IN THE RAT

The protective effect of two types of vitamin E (a-tocopherol and gamm a-tocotrienol) in rats treated with diethylnitrosamine (DEN) and 2-ace tylaminofluorene (AAF) were studied by determination of plasma alkalin e phosphatase (ALP), plasma and liver microsomal gamma-glutamyl transp eptidase (GGT) activities, and blood glutathione (GSH). Rats treated w ith DEN/AAF had significantly elevated plasma and microsomal GGT, plas ma ALP activities, and blood GSH levels compared with the normal contr ols (p<0.05). Supplementation with vitamin E of normal controls did no t affect the enzyme activities or blood GSH. In rats treated with DEN/ AAF, vitamin E supplementation attenuated GGT and ALP activities and b lood GSH levels. The optimum dose required for highest attenuation of the tumor marker enzyme activities was 34 mg/kg diet for alpha-tocophe rol and 30 mg/kg diet for gamma-tocotrienol. Higher doses of the vitam in did not show further attenuation in the level of the tumor marker e nzyme activities.