Carnosine supplementation and retina oxidative parameters in diet-induced obesity model

Abstract

AbstractPurpose:To describe retina oxidative parameters and carnosine influence in diet-induced obesity model.Methods:Wistar rats were randomly divided into four groups: Standard diet (SD), high sugar-fat diet (HcD), standard diet + carnosine (SD+Carn), and high sugar-fat diet + carnosine (HcD+Car). Evaluation in animals included body weight, adiposity index, plasma glucose, total lipids, high density lipoprotein (HDL), and low-density lipoprotein (LDL), uric acid, creatinine, and triglycerides. The retinas were analyzed for markers of oxidative stress. Hydrogen peroxide production was assessed by oxidation of 2', 7'-dichlorodihydrofluorescein diacetate (DCFH-DA). The analysis of the antioxidant system included total glutathione (tGSH), total antioxidant capacity (TAC), protein carbonyl, and sulfhydryl type.Results:The hypercaloric diet induced higher body weight, adiposity index, glucose, and triglyceride. Carnosine supplementation influenced on plasma triglyceride. Absence of diet effect was verified in retina fluorescent derivative of oxidized DCFH-DA (DCF), TAC, GSH reduced levels and GSH:GSSG ratio. High retina TAC levels were found in rats treated with carnosine. Retina GSH reduced levels and GSH:GSSG ratio improved in carnosine-supplemented rats treated with high sugar-fat diet (vs.SD+Car). Diet was associated with increase in retina carbonyl content and decrease in sulphydryl levels. However, carnosine supplementation had no interference in both retina parameters from animals treated with high sugar-fat diet.Conclusion: The results suggest that the sugar- and fat-enriched diet fed the rats may trigger an imbalance in the retinal redox state and that carnosine may improve the oxidative parameters.