Aqueous extract of Terminalia arjuna prevents cyclosporine-induced renal disorders

Abstract

Cyclosporine (CsA), a powerful immunosuppressant, had a significant impact on transplantation medicine, and exposure to this chemical is known to induce oxidative stress and causes renal injury by the formation of free radicals. Acute and chronic renal damage are very common pathophysiologic disturbances caused by CsA. The present study has been conducted to evaluate the protective role of the aqueous extract of the bark of Terminalia arjuna (TA), an important Indian medicinal plant widely used in the preparation of ayurvedic formulations, on CsA-induced oxidative stress and resultant dysfunction in the rat kidney. Animals were treated with the aqueous extract of TA (100 mg/kg body weight (b.wt)) and then treated with CsA (25 mg/kg b.wt) in olive oil for 14 days. The level of urea, uric acid, and creatinine was determined from serum sample. The enzymes, namely, alkaline phosphatase (ALP), acid phosphatase (ACP), aspartate transaminase (AST), and alanine transaminase (ALT), and enzymic indices of membrane integrity such as Na+K+ATPase, Ca2+ATPase, and Mg2+ATPases were estimated in the tissue of all study groups. Antioxidant status in kidney tissues was estimated by determining the activities of the antioxidative enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione transferase (GST) and the levels of reduced glutathione, vitamin E, and vitamin C. In addition, the kidney phospholipids, cholesterol, triglycerides, and free fatty acids were determined in the tissue. Results showed that CsA caused a marked increase in the levels of urea, uric acid, and creatinine in serum and decreases the levels of ALP, ACP, AST, ALT, Na+K+ATPase, Ca2+ATPase, Mg2+ATPases, SOD, CAT, glutathione reductase, GST, GPx, vitamin E, and vitamin C whereas cholesterol, triglycerides, free fatty acid, and phospholipid levels were found to be increased in the kidney tissue homogenates of CsA-treated rats. Aqueous extract of TA successfully prevented the alterations of these effects in the experimental animals. Data also showed that the extract possessed strong free radical scavenging activity comparable to that of vitamin C. Our study demonstrated that the aqueous extract of the bark of TA could protect the kidney tissues against CsA-induced oxidative stress probably by increasing antioxidative defense activities.