Effect of α-tocopherol on antioxidant enzyme activities and lipid peroxidation in rainbow trout (Oncorhynchus mykiss)

Abstract

In this study, the effect of α-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 α-tocopherol injection. In addition, the levels of malondialdehyde (MDA) as a lipid peroxidation marker were determined in the erythrocytes. The results showed that α-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 α-tocopherol treatment (p < 0.05). The results suggest that α-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, α-tocopherol should be used carefully in all applications in relation to fish.

Quercetin protects rat skeletal muscle from ischemia reperfusion injury

“…When the extreme O 2 À occurs SOD reduces the amount of superoxide radicals (O 2 À ) by converting to oxygen (O 2 ) and hydrogen peroxide (H 2 O 2 ) [75][76][77] . CAT is primary enzymatic defence against H 2 O 2 generation 78,79 . GPx protects the tissues against free radicals by limiting lipid peroxidation.…”

A comparative study on the antioxidant effects of hesperidin and ellagic acid against skeletal muscle ischemia/reperfusion injury

“…The results were expressed as Units per milligrams of protein tissue. CAT activity in muscle tissue was measured using spectrophotometric methods 29,30 . Results were expressed as units per grams of protein.…”

The effects of some bromophenols on human carbonic anhydrase isoenzymes

“…In a recent study, it was demonstrated that dimethoxy-bromophenol derivatives incorporating cyclopropane moieties have shown picomolar inhibition against cytosolic CA I, II and tumor-associated CA IX, and XII 9 . The relationship between anti-oxidant molecules and CA isoenzyme inhibition is well established [56][57][58] . It is well known that bromophenol derivatives had some biological activities including anti-oxidant and radical scavenging 55 , acetylcholine esterase inhibition properties 55,59 .…”