Histopathological Evaluation and Immunomodulatory Effects of Methanolic Leaf Extracts of Rauwolfia vomitoria and Aframomum melegueta in Cadmium Chloride Induced Renal Toxicity

Abstract

Cadmium is a major cause of nephrotoxicity and has also been linked to hepatotoxicity, carcinogenicity, and reproductive toxicity. This study investigated the ameliorative potential of methanolic extracts of R. vomitoria and A. melegueta on cadmium-induced renal toxicity. Twenty-five adult male Wistar rats weighing 180 to 200g were divided into five groups of five rats each. The first group consisted of unexposed control rats, while the second consisted of cadmium-exposed untreated rats that were orally administered 12mg/kg/bw cadmium chloride (CdCl2). The rats in groups III-V were orally exposed to CdCl2 at standard doses of 12mg/kg/bw and treated with R. vomitoria (200mg/kg/bw), A. melegueta (200mg/kg/bw), and co-administration with R. vomitoria (200mg/kg/bw) and A. melegueta (200mg/kg/bw) respectively. The rats were euthanized after 28 days and their kidneys were harvested and processed for histopathological examination, mRNA expression of TGFβ, ELISA evaluation of superoxide dismutase (SOD), glutathione peroxidase (GPx), tumour necrosis factoralpha (TNF-α) and interleukin-6 (IL-6). The CdCl2 exposed rats had reduced SOD, GPx levels and elevated TNF- α and IL-6 levels (P<0.05), whereas co-administration of R. vomitoria and A. melegueta ameliorated the oxidative damage, modulated TGF-β expression levels while also mitigating histological alterations associated with CdCl2 exposure. The study concluded that R. vomitoria and A. melegueta at standard doses of 200mg/kg/bw mitigate CdCl2-induced kidney toxicity in exposed rats