Effect of Piper betel leaf extract on learning and memory in Aluminium chloride induced Alzheimer’s disease in Wistar rats

Abstract

Alzheimer's disease is a common neurological disorder affecting a significant proportion of the elderly population.There are only a few drugs which can be used safely to treat it. We sought to investigate for the first time Piper betel leaf, a postmeal mouth freshener for its potential use in Alzheimer's disease. Five groups of male Wistar rats with six rats in each group aged 10-12 weeks were used. The control group received the distilled water, aluminium chloride (AlCl3) group was treated with AlCl3, the standard group was treated with rivastigmine with AlCl3, and the two test groups received piper betel leaf extract (PBE) at doses of 400mg/kg and 500mg/kg body weight with AlCl3. AlCl3 was administered orally for 42 days in all the treated groups. Memory and learning were evaluated by Morris water maze test and Passive avoidance test.The results of the Morris water maze test showed reduced mean escape latency period in all the groups on trial day three (P≤0.05) and on trial day four (P ≤0.01) compared to AlCl3 group. The retention of spatial memory by probe trial showed that PBE and rivastigmine treated group spent more time in the target (platform) quadrant when compared to AlCl3 group (P≤0.01). The passive avoidance test showed a significant increase in step through latency in standard and test groups compared to the AlCl3 treated group. The weight of the rats treated with AlCl3 and PBE was reduced at the end of the treatment period while increased in standard and control group. The study shows the beneficial effects of Piper betel leaves in Alzheimer’s disease by significantly improving the learning and memory functions in rats.