Effect of Cocos nucifera L. Water on Scopolamine-Induced Memory Impairment in the Wistar Rat

Abstract

Memory loss is an important Alzheimer's disease indicator (AD) linked with hippocampal damage. Scopolamine (SCO) antagonizes muscarinic acetylcholine receptor (mAChR) whose effect is similar to AD symptoms. Cocos nucifera L. (coconut) water is a crucial biological fluid containing nutritional components, and consumed for its health benefits. This study investigated the effect of C. nucifera water on memory impairment caused by SCO in rats. Thirty-two male Wistar rats were divided into four groups (n=8): control (normal saline); SCO (1 mg/kg/i.p.), C. nucifera water (0.4 mL/20 g) + SCO (1 mg/kg/i.p.), and donepezil (5 mg/kg/i.p.)+ SCO (1 mg/kg/i.p.). The levels of acetylcholinesterase (AChE), brain-derived neurotrophic factor (BDNF), interleukin-6 (IL-6), tumour necrosis factor (TNF-α), and cyclo-oxygenase-2 (Cox-2) were measured. Hippocampal histology was done. Utilizing GraphPad Prism for statistical analy-sis, pre-treatment with C. nucifera water and donepezil displayed higher (p<0.01) spontaneous alternation in the Y-maze, and decreased escape latency, increased entries and time spent in the target quadrant (p<0.01) of the Morris water maze compared to the SCO group. These pre-treatment also inhibited AChE activity (p<0.001), and reduced expressions of IL-6, TNF-α and Cox-2 (p<0.001). However, there were no marked differences (p>0.05) in BDNF across the groups. Histology of SCO-only group revealed degenerated neurons, whereas the pre-treated groups showed regenerated neurons with less necrotic cells. The administration of SCO to the rats resulted in some form of memory impairment, and C. nucifera water showed promise for reversing this deficits