Toxicological Assessment of Methanol Root Extract of Newbouldia laevis in Rats After Therapeutic Evaluation Against Plasmodium berghei in Mice

Abstract

This study evaluated the toxicity of methanol extracts of Newbouldia  laevis in rats. Phytochemical screening was done using standard methods. Twenty five Wistar rats were divided into five groups of five rats each. The control group received 0.9% normal saline. The remaining groups were administered once daily for four days; 125, 250, 500, and 750 mg/kg body weight of the extract and afterwards monitored for 14 days. At the end, blood and organ samples were collected for biochemical, hematological and histopathological evaluation. Appreciable amount of flavonoids, alkaloids, saponins, tannins, oxalate and phytate were present. Significantly increased ALT activity of 65.28±1.55 U/L and 71.05±1.28 U/L were recorded at higher extract treatment doses of 500 and 750 mg/kg respectively compared to 34.71±1.99 U/L for the Control, just as AST and ALP presented similar trend of increased activities. Concentrations of total protein dropped from 74.74±2.25 g/dL (control) to 34.49±4.97 g/dL, while  Urea (11.91±0.20 mg/dL) and creatinine (108.88±5.31 mg/dL) increased significantly compared to 5.36±0.41 mg/dL and 68.23±3.33 mg/dL recorded for controls respectively, indicating dose-dependent liver and kidney dysfunction. Other liver, kidney and haematological parameters varied significantly (p ≤ 0.05) compared to the Control. Organ histology revealed pathological abnormalities in liver and kidney of treated rats at higher doses. This evaluation presented significant dose-dependent alterations in biochemical, haematological, histological parameters, indicating potential organ-specific toxicity at higher doses. These findings have shown N. laevis methanol root extract as a potential alternative treatment for malaria and a source for drug development having shown potent antiplasmodial properties, however, proper dose regulation is needed in the use.