THE EFFECT OF SUBACUTE ADMINISTRATION OF A NEEM PESTICIDE ON RAT METABOLIC ENZYMES

Acute toxicity of a neem pesticide (Vepacide-Tech) was studied in male Wistar rats by oral (single) intubation for 7 days. Vepacide was foun d to be moderately toxic to rat based on LD50 value. Subacute toxicity of Vepacide-Tech was also studied in mate rats by oral (multiple) int ubation of low (80 mg Kg(-1) day(-1)), medium (160 mg Kg(-1) day(-1)) and high dose (320 mg Kg(-1) day(-1)) for 90 days. High dose caused a significant decrease in Cytochrome P-450 (Cyt.P-450) concentration at 45 and 90 days and the medium dose caused same effect at 90(th) day in liver and lung. Kidney showed similar effect at 90 days by the three doses. Cytochrome b(5) (Cyt.b(5)) concentration was significantly decr eased in liver, lung and kidney at 45 and 90 days at medium and high d oses. Brain Cyt.b(5) concentration was decreased on 90(th) day at high dose. Cytochrome P-450 reductase (Cyt.P-450 reductase) concentration ;was decreased significantly in river and brain at 45 and 90 days, res pectively at medium and high doses. The withdrawal study (28 days) has shown significant recovery. These results demonstrate that low levels exposure of Vepacide may have significant effect on the xenobiotic de toxification mechanism of different tissues of rat.