ABSTRACT
The present investigation was undertaken to discover by enzmological studies whether supplementation of Nigella sativa seeds powder in the food of rats treated with carcinogenic substances dibutylnitrosamine [DBNA] and diethylnitrosamine [DENA] prevents rat liver toxicity. For this purpose, the activity of the enzymes. glucose-6-phosphatase [G6P].5 nucleotidase [5 N], acid phosphatases [AP] and alkaline phosphatases [ALP] were studied histochemically. It has been observed that DBNA and DENA disturb enzyme activity in the liver as DBNA and DENA depressed G6P, 5N and AP and increased ALP in liver cells. Supplementation of Nigella sative seeds powder in the food, prevents or decreases the effect by inhibiting the decrease of the enzymes G6P, 5 N, AP and the increase of the enzyme ALP in liver cells by the carcinogenic substances. In addition, enzyme activities which were studied histochemically are good markers in carcinogenesis studies of antitumor activities