title: Lipid peroxidation and antioxidant defense enzymes in Clarias gariepinus as useful biomarkers for monitoring exposure to polycyclic aromatic hydrocarbons.
abstract: The toxicological evaluations of crude oil, xylene, toluene and benzene were carried out against juvenile stages of Clarias gariepinus. On the basis of LC(50) value, benzene (0.017 ml/l) was found to be the most toxic followed by xylene (0.086 ml/l), toluene (0.398 ml/l) and crude oil (2.219 ml/l) was the least toxic. The results of the lipid peroxidation assay showed that the level of malonaldehyde (MDA) in liver and gills of fish exposed to all the test chemicals increased significantly (P < 0.05) when compared to control. Measurement of activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) in liver and gill of fishes exposed to sublethal concentration of the test chemicals over a 28-day period was found to decrease significantly (P < 0.05) when compared to control. The observed reduction in the activities of antioxidant defense enzymes such as SOD, CAT and GST in conjunction with an increase in MDA levels in the gill and liver tissues of test animals exposed to aromatic hydrocarbon compounds were recommended as a good battery of biomarkers for early detection of pollution during biomonitoring programmes.
authors.affiliation: Department of Zoology, Ecotoxicology Unit, Faculty of Science, University of Lagos, Akoka, Lagos, Nigeria. bayotitoloju@yahoo.com
authors.forename: Adebayo
authors.initials: A
authors.lastname: Otitoloju
authors.forename: Oluwatoyin
authors.initials: O
authors.lastname: Olagoke
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002397:Catfishes / Q000378:metabolism*; D004784:Environmental Monitoring / Q000379:methods*; D005880:Gills / Q000187:drug effects / Q000201:enzymology; D005982:Glutathione Transferase / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects*; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D009549:Nigeria; D059392:Petroleum Pollution / Q000009:adverse effects / Q000032:analysis / Q000706:statistics & numerical data; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D002374:Catalase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase