Antioxidant, lipid modulating and hypoglyceamic effects of the aqueous extract of Anacardium occidentale leave in streptozotocin-induced diabetic rats

Abstract

Sarah Onyenibe Nwozo, Ayodeji Babatope Afolabi, Babatunji Emmanuel oyinloye

Background/Aim: Anacardium occidentale leaves are used traditionally for the management of diabetes. This study seeks to evaluate the efficacy and safety of its continuous intake for 4 weeks in streptozotocin-induced diabetic rat model in comparison with metformin a reference drug. Materials and Methods: Thirty-six male Wistar rats (130 -145 g) were randomly divided into 6 groups of six animals each. Diabetes was induced in rats by a single intraperitoneal injection of streptozotocin (STZ; 50 mg/kg bw); plant extract and metformin were given orally (60 and 125 mg/kg/ bw). Results: Diabetes induction caused a significant weight loss (23.65 %) associated with a marked rise in levels of fasting blood glucose (295 mg/dl), triglycerides, total cholesterol, low-density-lipoprotein cholesterol, lipid peroxidation and serum aminotransferase activities. Besides, glucose-6-phosphate dehydrogenase (G6PD) activities, total protein concentration, high-density-lipoprotein cholesterol and tissue antioxidants (reduced glutathione; GSH, superoxide dismutase; SOD, catalase; CAT, glutathione-S-transferase; GST, Glutathione peroxidase; GPx) were diminished in STZ-induced diabetic rats. Histopathological studies also revealed various degrees of alteration in the liver diabetic rats. The effects of A. occidentale extract were compared with metformin as a reference antidiabetic drug. Treatment with A. occidentale (60 mg/ kg/ bw) extract showed a significant (P<0.05) reversal effect that ameliorated the deleterious effect of STZ in all the biochemical parameters evaluated. Conclusion: Aqueous extract of A. occidentale leaves exhibits excellent antioxidant, hypoglycemic and antidiabetic effects and may be used as a therapeutic agent in the management of diabetes and its associated complications with caution as observed in histopathological studies.