QUERCETIN AMELIORATES DIABETIC NEPHROPATHY IN RATS VIA MODULATION OF RENAL NA + , K + -ATPASE EXPRESSION AND OXIDATIVE STRESS

Abstract

Diabetic Nephropathy (DN) is one of most prevalent complications of Diabetes Mellitus (DM), therefore prevention of its development is a important field for researches. Quercetin is a plant flavenoid with hypoglycemic and antioxidant properties that is cla imed to have a reno-protective effect in diabetes. This study was designed to investigate the reno-preventi ve role of Quercetin treatment in terms of biochemi cal and pathological changes in diabetic rats and to de termine whether the effect is mediated through modulation of oxidative stress and Na + , K + ATPase expression and activity. Sixty male Sprague-Dawley rats were distributed equally among 6 groups: (i) Contro l group (C), (ii) Quercetin treated Control group ( CQ), (iii) Diabetic group (D), (iv) Diabetic Insulin tre ated group (DI), (v) Diabetic Quercetin treated gro up (DQ) and (vi) Diabetic Insulin and Quercetin treated gro up (DIQ). Systolic blood pressure was measured at t he end of the experiments (8 weeks). Retro-orbital blo od samples were used to determine the serum levels of glucose, HbA1c, urea, creatinine, Na + and K + . Renal homogenate levels of Na + , K + ATPase activity, Malondialdehyde (MDA0, Superoxide Dismutase (SOD) and Glutathione Peroxidase (GPx) were measured. Semiquantitative reverse transcriptase-PCR Na + , K + ATPase expression assays and kidney histopathological examination were conducted. Treatment with either insulin or Quercetin alone resulted in partial rever sal of the biochemical and histopathological signs of neph ropathy in diabetic rats. This was associated with partial but significant amelioration of indicators of oxida tive stress and Na + , K + ATPase gene expression and activity. However only combined treatment by both insulin and Quercetin significantly improved all of the aforementioned parameters up to the control levels. These results suggested that combined therapy with insulin and Quercetin might be a useful preventive tool aga inst development of DN.