31 Bulletin UASVM, Veterinary Medicine, 70(1)/2013 Print ISSN 1843-5270; Electronic ISSN 1843-5378 Effects of Quercetin and Chronic (Training) Exercise on Oxidative Stress Status in Animals with Streptozotocin-Induced Diabetes CHIŞ Irina Camelia* 1 , Doina BALTARU 2 , Monica MAIER 3 , Adriana MUREŞAN 1 , Simona CLICHICI 1 1 University of Medicine and Pharmacy “Iuliu Hatieganu”, Cluj-Napoca, Romania, 2 ”Constantin Papilian” Military Emergency Hospital, Cluj-Napoca, Romania, 3 Technical University of Cluj-Napoca, University Center North of Baia Mare, Romania, *Corresponding author: irinnaus@yahoo.com Abstract. Increasing evidence in both experimental and clinical studies suggests that oxidative stress is involved in the pathogenesis and progression of diabetic tissue damage. This study investigated the effects of chronic exercise training associated with chronic oral administration of Quercetin on blood glucose levels and oxidative stress status in streptozotocin-induced diabetic Wistar rats. Adult male Wistar rats were divided into seven groups: Group I: non-diabetic, sedentary control rats; Group II: non-diabetic, trained control rats; Group III: non-diabetic, trained control rats treated with Quercetin; Group IV: diabetic, sedentary control rats; Group V: diabetic, trained control rats; Group VI: diabetic, sedentary rats treated with Quercetin; Group VII: diabetic, trained rats treated with Quercetin. Quercetin was administered via an intragastric tube (0.6 ml/rat), at a dose of 20 mg/kg body weight/day for 4 weeks after the induction of diabetes mellitus. Diabetes was induced by a single i.p. injection of streptozotocin (40 mg/kg body weight). Animals were sacrificed at the end of a 4-week swimming training program (1 hour/day, 5 days/week, 4 weeks). The glycemic profile, oxidative status (lipid peroxidation and protein oxidation) and antioxidant levels (superoxide dismutase, catalase and reduced glutathione) were evaluated. When compared to diabetic sedentary rats, the animals submitted to chronic exercise presented significantly lower glycaemic values, and significantly increased oxidative stress levels. The diabetic, trained rats treated with Quercetin presented significantly lower glycaemic values accompanied by a remarkable reduction of oxidative markers. The results suggested that chronic exercise training associated with Quercetin administration could lower blood glucose levels and reduce oxidative stress in in streptozotocin-induced diabetic rats. Keywords: diabetes, exercise, oxidative stress, Quercetin INTRODUCTION Diabetes mellitus (DM) is one of the most common endocrine-metabolic disorders contributing to high morbidity and mortality rates (Di Naso et al., 2011). Due to population aging, urbanization, increased prevalence of obesity and physical inactivity, the number of individuals affected by DM is increasing all over the world. Diabetes is an increasing health problem worldwide. In recent years, more and more researchers suggested that the implications of oxidative stress in the pathogenesis and progression of diabetic tissue damages in addition to diabetic complications. Hyperglycemia and hyperlipidemia are promoters of diabetes dysmetabolism through the formation of reactive oxygen species (ROS) due to increased mitochondrial production of the superoxide anion radicals, non-enzymatic glycation of proteins and glucose autoxidation (Formagio et al., 2013; Jeong et al., 2013). The ROS cause cell damage and insulin resistance. Moreover, both of them stimulate pro-inflammatory