Modulation of Masheri- and benzo[a]pyrene-inducible carcinogen-metabolizing enzymes by dietary vitamin A.
The modulatory role of dietary vitamin A on the carcinogen metabolizing enzymes was studied in masheri extract and benzo[a]pyrene-treated rats. Weanling male Sprague-Dawley rats were fed vitamin A deficient (SR-) and vitamin A sufficient (SR+) semisynthetic diets for 12 weeks. ME/B[a]P treatment significantly increased the phase I activating enzymes in both SR- and SR+ groups. However, a higher percentage increase in enzyme activities was observed in both liver and lung of the SR- animals compared to the SR+ groups. Glutathione content and activity of glutathione S-transferase were decreased in both liver and lung of SR- animals on treatment with either ME or B[a]P. In the SR+ group, an increase in GSH content and GST activity was observed following the ME/B[a]P treatment. The hepatic pool of vitamin A was depleted while that of vitamin C was increased after ME or B[a]P treatment in both SR- and SR+ groups.
Ammigan
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Carcinogenesis Division, Tata Memorial Centre, Parel, Bombay, India.
Nair
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D000818:Animals; D001205:Ascorbic Acid / Q000032:analysis; D001564:Benzo(a)pyrene / Q000633:toxicity*; D002273:Carcinogens / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis; D015786:Cytochromes b5 / Q000032:analysis; D004790:Enzyme Induction / Q000187:drug effects; D005978:Glutathione / Q000032:analysis; D005982:Glutathione Transferase / Q000032:analysis; D066298:In Vitro Techniques; D008099:Liver / Q000737:chemistry; D008297:Male; D010936:Plant Extracts / Q000633:toxicity*; D010947:Plants, Toxic; D051381:Rats; D011919:Rats, Inbred Strains; D014026:Nicotiana; D014801:Vitamin A / Q000032:analysis / Q000494:pharmacology*
D002273:Carcinogens; D010936:Plant Extracts; C057607:masheri; D014801:Vitamin A; D001564:Benzo(a)pyrene; D015786:Cytochromes b5; D003577:Cytochrome P-450 Enzyme System; D005982:Glutathione Transferase; D005978:Glutathione; D001205:Ascorbic Acid