Modulatory effect of Polyalthia longifolia leaves against cadmium-induced oxidative stress and hepatotoxicity in rats

Background Cadmium serves as a major pollutant in the environment and it has been documented for its widespread harmful effects. This study sought to investigate the prophylactic and the curative effects of aqueous and methanolic leaf extracts of Polyalthia longifolia against cadmium-induced hepatotoxicity in rats. Methods Animals in group I served as the normal control and administered distilled water only for 14 days, group II was administered cadmium (4 mg/kg/body weight) for 7 days, groups III and IV rats 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 another 7 days, serving as pre-treatment group, groups V, VI, VII, and VIII served as curative groups and were first exposed to cadmium for 7 days and then post-treated with 100 and 200 mg/kg body weight of aqueous extract and 100 and 200 mg/kg body weight of methanolic extract P. longifolia for another 7 days. Results Pre- and post-treatment with both extracts of P. longifolia revealed a significant hepatoprotective ability by decreasing the alanine transaminase, alkaline phosphatase, aspartate transaminase, acid phosphatase, gamma glutamyl transferase enzymatic activities were elevated due to cadmium intoxication. Pre- and post-treatment with aqueous and methanolic extract of P. longifolia extract significantly decreased hepatic malondialdehyde levels, together with an improvement in the antioxidant status of superoxide dismutase, glutathione peroxidase, catalase, glutathione S-transferase, and reduced glutathione of rats exposed to cadmium. Histopathology examinations also confirm the above biochemical findings. Conclusion The findings from this work suggested that P. longifolia may be beneficial in ameliorating the cadmium-induced hepatotoxicity and oxidative stress in rats.

Keywords: Polyalthia longifolia; antioxidant; cadmium; hepatotoxicity; oxidative stress.