Abstract

Aluminium chloride (AICl₃) is known as a potent environmental neurotoxin causing progressive neurodegeneration in the brain. Khaya grandifoliola (KG) is used in Cameroon in traditional medicine for its therapeutical properties. Thus, the aim of this study was to evaluate the neuroprotective effect of K. grandifoliola against AICl₃-induced neurotoxicity in rats. The KG25-fraction was obtained by maceration of the K. grandifoliola bark powder followed by fractionation by flash chromatography. The neuronal dysfunction induced by AICl₃ was evaluated on 36 rats divided into 6 groups of 6 rats each during 45 days. On day 46 after 24 h of fasting, the rats were sacrificed. AST, ALT, PAL, catalase activity, glutathione level, peroxidized lipid level and acetylcholinesterase activity were assessed. AICl₃-induced anxiety was reduced by administration of the K. grandifoliola 25-fraction. The oxidative stress response of the K. grandifoliola 25 fraction showed a significant increase (p<0.05) in catalase activity at the dose of 225 mg/kg body weight, glutathione and lipid peroxidation levels followed the same pattern. Acetylcholinesterase activity showed a significant increase in group III (positive control) and a significant decrease (p<0.05) in the experimental groups. The K. grandifoliola 25 fraction effectively protects the brain of rats against the toxic effects of AICl₃ at doses (75 and 225 mg/kg) body weight, respectively.

Key words: K. grandifoliola 25, AICl_3, anxiety, neurotoxicity, oxidative stress.