Dose-dependent neurotoxicity and oxidative stress induced by Mucuna urens seed extract in the hippocampus of female wistar rats

Abstract

This study investigated the impact of Mucuna urens seed extract on the hippocampus of female Wistar rats, focusing on oxidative stress biomarkers and histomorphological alterations. A total of four groups of rats were orally administered 0 mg/kg (control), 300 mg/kg, 200 mg/kg, and 100 mg/kg of Mucuna urens extract, respectively for 21 days. The animals were anasthesized with chloroform and sacrificed after the last dose schedule. Subsequently, the skulls were cracked to remove the brain which were fixed in 10% buffered formalin solution. The brain tissues were taken to the laboratory for histology. Findings from biochemical analysis revealed a significant dose-dependent decrease in antioxidant enzyme activities such as catalase (CAT) and glutathione peroxidase (GPx) with the most severe reductions observed in the 300 mg/kg group (p < 0.05), indicating heightened oxidative stress. Findings obtained from histological examination using Hematoxylin and Eosin staining revealed progressive neuronal damage in the hippocampus characterized by pyknotic nuclei, cytoplasmic vacuolations, and disorganization of the pyramidal cell layer, especially at higher doses. These findings suggest that Mucuna urens seed extract induces oxidative damage and structural degeneration in the hippocampus in a dose-dependent manner. This study highlights the need for cautious use of Mucuna urens by people, especially in high concentrations, due to its potential neurotoxic effects.