Long-term consumption of virgin coconut (Cocos nucifera) oil diet impairs learning and memory in CD1 mice

摘要

Objective:Virgin coconut oil(VCO)has been used in the management of dementia in Alzheimer’s disease(AD).Therefore,this research investigated the effect of long-term consumption of VCO diet on learning and memory in CD1 mice.Methods:Thirty male CD1 mice(divided into three groups,n=10)were fed with standard rodent chow(control),5%and 20%VCO diets(respectively)for 28 d.The Morris Water Maze(MWM)test was used to test the effect of VCO on visuo-spatial learning and memory,while the Novel Object Recognition Test(NORT)was used to measure short-and long-term recognition memory.Results:Learning performance of mice did not differ in the MWM.During the probe trial,duration in the retention quadrant and annulus crossings were lower(P<0.05)in the 5%and 20%VCO diet groups compared to the control diet group,showing that VCO impaired visuo-spatial memory.During the NORT,mice showed more total approaches in the 20%VCO diet group(P<0.05)compared to control and the 5%VCO diet groups during the short-term memory test.During the long-term memory retention test,the total approaches were also higher in the 20%VCO group compared to control and 5%VCO group(P>0.05).The discrimination index was also lower in the 20%VCO group compared to control and 5%VCO diet groups indicating impaired long-term cognitive memory in mice given 20%VCO diet.Histological examination of brains showed damage within the CA1 pyramidal cell layer of the hippocampus in the 20%VCO diet group,in line with the behavioural observations.Conclusion:Long-term consumption of virgin coconut oil diet impairs memory in mice.