Protective effect of Geophila obvallata (Shumach) Didr leaf extract and its fractions against cadmium-induced nephrotoxicity in male Wistar rats

Abstract

Cadmium (Cd) is a known nephro-toxicant. This research determined the ameliorative effects of Geophila obvallata crude methanol extract (Me70) and its fractions on Cd-induced nephrotoxicity in Wistar rats. Male rats were randomly allocated to nine (9) groups of six (6) rats each. Group I was given normal water and feed only. Group II received 0.3 mg Cd/L only for two weeks. Groups III, IV, V, VI and VII were pre-exposed to aqueous, ethyl acetate, hexane, butanol and chloroform fractions of Me70, each at a dose of 50 mg/kg bwt for fourteen (14) days prior to treatment with 0.3 mg Cd/L for a further two weeks. Group VIII was pre-exposed to Me70 at a dose of 50 mg/kg bwt for fourteen (14) days, prior to administration of 0.3 mg Cd/L for fourteen (14) days, while group IX received 50 mg/kg.bwt of Me70 only for fourteen (14) days. The treatments were administered daily for twenty-eight (28) days via oral gavage. Cadmium levels in the kidney tissues of Cd-treated rats increased significantly while their body weights decreased relative to control. The levels of kidney function markers in the plasma, lipid peroxidation levels, catalase activity, metallothionine (MT-1) and kidney injury molecule-1 (KIM-1) mRNA were increased significantly, while glutathione (GSH) levels, activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-s-transferase (GST), and levels of nuclear factor erythroid-2-related factor 2 (Nrf-2), peroxisome proliferator-activated receptor –gamma coactivator- 1-alpha (PGC-1α), heme oxygenase-1 (HO-1) and NADH quinone oxidoreductase-1 (NQ-O1) were decreased significantly in rats treated with Cd-only. Overall, pre-treatment with Me70 produced better protection from the toxic effects of cadmium induction in experimental rats.