Antihyperglycemic and renal protective activities of Anacardium occidentale (anacardiaceae) leaves in streptozotocin induced diabetic rats

Abstract

Earlier studies from our laboratory have indicated hypoglycaemic action of Anacardium occidentale (AO) leaves in experimental type 1 diabetes. Streptozotocin-induced diabetes in rats had been shown to be associated with functional and/or morphological changes in the kidney. Therefore, in the present investigation, we carried out studies on streptozotocin (STZ)-induced type 1 diabetes in rats chronically treated with Anacardium occidentale on the functional and histological alterations of kidneys. Albino rats were divided into 7 groups (n=5) receiving graded doses of hexane extract of Anacardium occidentale leaf by gavage, (150 and 300 mg/kg/day) and insulin (5 IU/kg). Renal ultrastructure was studied by measuring: diameter of Bowman\'s capsule, distribution and total area occupied by glomerular capillaries, PAS positive structures. AO at the dose of 300 mg/kg/day, showed significant reduction (P<0.05) of blood glucose level, total protein excreted, glycosuria and urea in diabetic rats. Anacardium treatment, initiated 3 days after diabetes induction, reduced destruction of renal structure and other metabolic disturbances more than when treatment was initiated two weeks after. Histopathological study showed that A. occidentale significantly reduced accumulation of mucopolysaccharides in the kidneys of diabetic animals. The extract of AO at the dose of 300 mg/kg had no nephrotoxic potential in normal rats. The present study demonstrates the efficacy of Anacardium occidentale (hexane extract) in reducing diabetes-induced functional and histological alterations in the kidneys.

Keywords: Anacardium occidentale, hexane extract, diabetes mellitus, rats, nephropathy

African Journal of Traditional, Complementary and Alternative Medicines Vol. 3(1) 2006: 23-35