title: Effect of alpha-tocopherol on antioxidant enzyme activities and lipid peroxidation in rainbow trout (Oncorhynchus mykiss).
abstract: In this study, the effect of alpha-tocopherol on the antioxidant capacity of rainbow trout (Oncorhynchus mykiss) was determined. For this purpose, activities of antioxidant enzymes such as catalase (CAT), peroxidase (POD) and glutathione reductase (GSSG-Rx) were investigated. Enzyme activities were measured at 0 (control), 1, 3 and 5 h after alpha-tocopherol injection. In addition, the levels of malondialdehyde (MDA) as a lipid peroxidation marker were determined in the erythrocytes. The results showed that alpha-tocopherol significantly activated the CAT, POD and GSSG-Rx enzymes as compared with the enzyme activities found in the controls (p < 0.05). However, MDA levels were significantly decreased by alpha-tocopherol treatment (p < 0.05). The results suggest that alpha-tocopherol may have a pro-oxidant tendency at a high dose and cause mild oxidative stress which could modulate signal transduction cascades, redirect gene expression, and influence many cellular responses such as proliferation, differentiation, and reproduction. For this reason, alpha-tocopherol should be used carefully in all applications in relation to fish.
authors.affiliation: Department of Chemistry, Faculty of Science and Arts, Atatürk University, Erzurum, Turkey. igulcin@atauni.edu.tr
authors.forename: I
authors.initials: I
authors.lastname: Gülçin
authors.forename: S
authors.initials: S
authors.lastname: Beydemir
authors.forename: O
authors.initials: O
authors.lastname: Hisar
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects*; D017686:Oncorhynchus mykiss / Q000378:metabolism*; D009195:Peroxidase / Q000378:metabolism; D024502:alpha-Tocopherol / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D002374:Catalase; D009195:Peroxidase; D005980:Glutathione Reductase; D024502:alpha-Tocopherol