Effects of lauric acid on cognitive impairment in a scopolamine-induced Alzheimer's disease-like rat model

Abstract

Background: Alzheimer's disease (AD) is a multi-factorial type of dementia that poses a social and medical burden in that no effective treatment has been achieved yet. Impaired brain glucose metabolism is one of the major pathophysiological factors linked to its onset and progression. Lauric acid (LA) is a triglyceride with medium chain that can produce ketone body utilize by the brain as an alternative energy source.Objective: Therefore, the present study was carried out with the purpose of evaluating the effect of LA on cognitive impairments in scopolamine-induced AD-like rat model.Methods: Forty-two male Wistar rats were divided into six groups to receive normal saline, scopolamine, scopolamine with Donepezil, and scopolamine with varied doses of LA for a period of 21 days. Morris water maze (MWM) and Elevated Plus Maze (EPM) tests were performed to evaluate cognitive performance. After, brains were harvested and processed to assay for the level of malondialdehyde (MDA), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), acetylcholinesterase (AChE) and interleukin-6 (IL-6). Histological analyses using Haematoxylin and eosin staining was also performed.Results: The LA-treated groups demonstrated memory retention in the MWM and EPM tests, and showed increased levels of CAT, SOD, and GSH similar to the Donepezil group, in contrast to the scopolamine only group while MDA levels, IL-6, and AChE activity were reduced in the LA treated groups contrasted to scopolamine only group. LA reduces oxidative stress, neuroinflammation, and AChE activity, which indicates a possible ability of LA to protect against AD.

Keywords: Alzheimer’s disease; cognition; dementia; donepezil‌; lauric acid; scopolamine.