High Doses of Anacardium Occidentale Nut Shell Extract Induce Oxidative Damage in Cardiac and Renal Organs of Wistar Rats

Abstract

Anacardium occidentale (Cashew) is a plant reported to show several biological activities. The aim of this study is to examine the effects of methanol extract of Anacardium occidentale nut shell on the antioxidant status and histological features in cardiac and renal tissues of rats. Shells were obtained from the nut, air-dried, pulverized, and subjected to Soxhlet extraction to obtain Anacardium occidentale nut shell extract (AONSE). Forty-five male Wistar rats were divided into nine groups (5 rats each), and given oral gavage of corn oil (Control), and 50, 100, 150, 200, 250, 300, 350 and 400 mg/kg of AONSE, every other day for twenty-eight days. After sacrifice, heart and kidney were removed and divided into two portions each; one portion was homogenized for biochemical assays, while the other was fixed in formalin for histopathology. Superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione-S-transferase (GST) and Malondialdehyde (MDA) levels in the two organs were spectrophotometrically assayed. Histopathology of the organs was also done. The SOD and catalase were reduced in heart at high doses of AONSE relative to control. The AONSE has no significant effects on GPx, GST and MDA in the two organs, comparable to control. Photomicrographs of heart show, myocardial distortions and fibrosis, while glomerular fluid accumulation and hemorrhagic fibrosis were observed in kidney, at high doses, as against control and low doses of AONSE. This study shows that high doses of Anacardium occidentale nut shell extract could induce cytological derangements in heart and kidney of rats, possibly via oxidative mechanism.