Influence of Polyalthia longifolia (Sonn) leaves on oxidative stress biomarkers in the kidney of cadmium-induced toxicity rats

Abstract

Polyalthia longifolia (Sonn.) (False ashoka) is well-known in traditional system of medicine for its medicinal and therapeutic uses. However, the ameliorative effect of this plant against cadmium-induced oxidative stress in rat model has not been reported. Hence, this preliminary study investigates the prophylactic and the curative effects of aqueous and methanolic leaf extracts of Polyalthia longifolia against cadmium-induced nephrotoxicity in rats. Animals in group I served as control and administered distilled water only; group II was administered cadmium (4 mg/kg/body weight) every other day for 14 days; rats of groups III and IV served as the prophylactic group and were pre-treated with P. longifolia aqueous and methanolic leaf extract for 7 days and then exposed to cadmium for 7 days; and groups V, VI, VII, and VIII served as curative groups and were firstly exposed to cadmium for 7 days and then post-treated with 100 mg and 200 mg/kg body weight of aqueous extract and 100 mg and 200 mg/kg body weight of methanolic extract P. longifolia for another 7 days. Cd intoxication significantly (p < 0.05) increased the activities of serum creatinine and C-reactive protein levels. Cd exposure caused a significant increase (p < 0.05) in tissue total cholesterol and triglyceride levels. The levels of renal antioxidant parameters: glutathione-s-transferase, superoxide dismutase, catalase, glutathione reductase, and reduced glutathione, were significantly (p < 0.05) decreased in Cd-intoxicated rats with concomitant elevation of lipid peroxidation. Histopathological examination confirms the biochemical findings. Pre- and post-treatment with P. longifolia restored antioxidant status, improved lipid profiles, and attenuated the lesions in the tissues. Both extracts of P. longifolia protects against Cd-induced kidney toxicities via antioxidant activities.