title: Silymarin prevents benzo(a)pyrene-induced toxicity in Wistar rats by modulating xenobiotic-metabolizing enzymes.
abstract: Benzo(a)pyrene (B(a)P), which is commonly used as an indicator species for polycyclic aromatic hydrocarbon (PAH) contamination, has a large number of hazardous consequences on human health. In the presence of the enzyme cytochrome-P-450 1A1 (CYP1A1), it undergoes metabolic activation to form reactive intermediates that are capable of inducing mutagenic, cytotoxic, teratogenic and carcinogenic effects in various species and tissues. Research within the last few years has shown that flavonoids exhibit chemopreventive effect against these toxins. In the present study, the protective effect of silymarin (a flavonoid) against B(a)P-induced toxicity was monitored in Wistar rats by evaluating the levels of hepatic phase I (CYP1A1), phase II enzymes (glutathione-S-transferase, epoxide hydroxylases, uridinediphosphate glucuronosyltransferases,
  quinone oxidoreductase 1, sulfotransferases), cellular antioxidant enzyme heme oxygenase and total glutathione. The results reveal that silymarin possesses substantial protective effect against B(a)P-induced damages by inhibiting phase I detoxification enzyme CYP1A1 and modulating phase II conjugating enzymes, which were confirmed by histopathological analysis. Overall, the inhibition of CYP1A1 and the modulation of phase II enzymes may provide, in part, the molecular basis for the effect of silymarin against B(a)P.
authors: Department of Biotechnology, Alagappa University, Karaikudi, Tamil Nadu, India.
authors: P V
authors: PV
authors: Kiruthiga
authors: Centre for Pheromone Technology, Department of Animal Science, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India.
authors: K
authors: K
authors: Karthikeyan
authors: Centre for Pheromone Technology, Department of Animal Science, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India.
authors: G
authors: G
authors: Archunan
authors: Department of Biotechnology, Alagappa University, Karaikudi, Tamil Nadu, India.
authors: S Karutha
authors: SK
authors: Pandian
authors: Department of Biotechnology, Alagappa University, Karaikudi, Tamil Nadu, India devikasi@yahoo.com.
authors: K Pandima
authors: KP
authors: Devi
mesh_terms: D000818:Animals; D001564:Benzo(a)pyrene / Q000633:toxicity*; D056486:Chemical and Drug Induced Liver Injury / Q000201:enzymology* / Q000517:prevention & control*; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D004794:Enzyme Repression; D005260:Female; D008099:Liver / Q000473:pathology; D020011:Protective Agents / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012838:Silymarin / Q000494:pharmacology*
chemical_list: D020011:Protective Agents; D012838:Silymarin; D001564:Benzo(a)pyrene; D019363:Cytochrome P-450 CYP1A1
keywords: CYP1A1; Silymarin; benzo(a)pyrene; histopathology; phase II enzymes