title: Effect of tobacco extract and N'-nitrosonornicotine on the carcinogen metabolising enzymes under different dietary vitamin B status.
abstract: Studies were carried out to evaluate the changes in the phase I and II enzymes of xenobiotic metabolism, on treatment with tobacco extract (TE) and a tobacco specific carcinogen, N'-nitrosonornicotine (NNN) in Sprague-Dawley rats maintained on vitamin B complex sufficient and deficient semi-synthetic diets. Both TE and NNN significantly increased the hepatic and pulmonary phase I enzymes in the vitamin B sufficient (SB+) and deficient (SB-) animals. However, the percent increase in enzyme activities was drastically higher in the SB- treated group as compared to those in the SB(+)-treated group. On the other hand, TE and NNN significantly depressed the liver and lung glutathione (GSH) level and glutathione S-transferase (GST) activity in the SB- animals, while the opposite effect was observed in the SB(+)-treated animals. Furthermore, both the treatments depleted the hepatic pool of vitamin A, with a concurrent increase in that of vitamin C in SB+ and SB- groups.
authors.affiliation: Carcinogenesis Division, Tata Memorial Centre, Parel, Bombay, India.
authors.forename: N
authors.initials: N
authors.lastname: Ammigan
authors.forename: U J
authors.initials: UJ
authors.lastname: Nair
authors.forename: A J
authors.initials: AJ
authors.lastname: Amonkar
authors.forename: S V
authors.initials: SV
authors.lastname: Bhide
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism; D002273:Carcinogens / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D008099:Liver / Q000201:enzymology / Q000378:metabolism; D008168:Lung / Q000201:enzymology; D009602:Nitrosamines / Q000494:pharmacology*; D010936:Plant Extracts; D010947:Plants, Toxic; D051381:Rats; D011919:Rats, Inbred Strains; D014026:Nicotiana; D014801:Vitamin A / Q000378:metabolism; D014803:Vitamin B Complex / Q000502:physiology*; D014804:Vitamin B Deficiency / Q000503:physiopathology
chemical_list: D002273:Carcinogens; D009602:Nitrosamines; D010936:Plant Extracts; D014801:Vitamin A; D014803:Vitamin B Complex; D003577:Cytochrome P-450 Enzyme System; D005978:Glutathione; D001205:Ascorbic Acid; C008655:N'-nitrosonornicotine