Publications scientifiques
Fils Armand Ella
Mario Robillard Didier Koloko
Pascal Owona
Simon Ngamli Fewou
American Journal of Biomedical and Life Sciences
Alzheimer’s disease (AD) is a multifactorial, progressive neurodegenerative disorder with dementia and persistent impairment of cognitive functions as the main clinical characteristics. Although signs of progress are being made in developing AD therapy, there is no effective drug capable of stopping and/or slowing down the progression of the disease. We have previously indicated in an in vitro setting of AD that <i>Khaya grandifololia</i> (KG) crude extract possesses antioxidant, anti-inflammatory, and neuroprotective activities. In the current work, we have evaluated the activity of KG hydroethanolic (KG-HE) extract in preventing cognitive impairment and promoting memory improvement in vivo. Results from behavioral tests indicated a significant improvement in memory performance and a delay in depression-like behavior upon treatment of rats with KG-HE extract (5, 25, and 50 mg/kg) or donepezil (1 mg/kg) as standard. Because scopolamine (1 mg/kg) impaired cognitive performance in the tail suspension test, Morris Water Maze test, and Novelty Suppressed Feeding Test, KG-HE extract (5, 25, and 50 mg/kg) or donepezil (1 mg/kg) treatment prevented scopolamine-induced performance impairment. Moreover, both KG-HE extract (5, 25, and 50 mg/kg) and donepezil (1 mg/kg) prevented the scopolamine-induced cognitive impairment by inhibiting the acetylcholinesterase activity. In addition, the brain parameters of stress oxidation (SOD, CAT, and GSH) reduced by scopolamine treatment were regulated by the administration of KG-HE extract or the standard drug donepezil. An increase in the MDA level and the phosphatase activity both in the serum and brain due to scopolamine treatment was restored by the administration of KG-HE extract or donepezil. Taken together, these results suggest that KG-HE extract improves cognition and relieves the scopolamine-induced cognitive impairment via activation of the cholinergic and anti-oxidation systems in rats.
