Virgin Coconut Oil Improved Discriminative Learning and Working Memory in Aging Cycling and Non-Cycling Female Sprague-Dawley Rats Supporting Its Beneficial Effect in Retarding Age-Related Cognitive Decline

Aim: Beneficial effects of virgin coconut oil (VCO) consumption to improve cognition in menopausal females remain inconclusive. This study examined the effect of VCO supplementation in aging cycling and non-cycling rodents to assess its impact on cognition. Methods: Sprague-Dawley rats (10 - 18 months) were randomly assigned to a supplemented VCO group (SVCO) that received oral doses of 1.42 mL/kg/day VCO (n = 10) and a non-supplemented (NVCO) group (n = 10). Their performance in a biased Y-maze discriminative learning paradigm was assessed over a 16-week period. Rats were initially allowed 3 minutes to explore the maze (habituated) and subsequently pre-trained in the non-preferred, white chamber to associate the presentation of a tone with a treat (reward). Training involved 4 daily trials initially for 3 weeks during which rats were rewarded if they entered the white arm within 15 sec after tone presentation. Time (days) to attain at least 75% correct responses (CR) determined acquisition latency (AL). Memory retention (MR1) of the learned task was assessed following a 1-week break from training and absence of supplementation (session T1). Following an additional 2-week break, supplementation of SVCO animals resumed and continued to week 16. In week 14, all animals received re-training for 1 week (session T2) followed by another 1-week break and subsequent assessment of memory (MR2). Vaginal smear cytology determinations were performed throughout the study to identify cycling and non-cycling rats. Student’s t-test and ANOVA with Brown-Forsythe and Tukey’s post-hoc tests were used to compare means. Results: C-SVCO rats attained lower AL, and higher CR and MR scores vs their NVCO counterparts (p < 0.05). At session T2, NC-SVCO rats out-performed other groups (p = 0.048, F = 2.64), attaining highest CR scores between sessions (p = 0.026). Conclusion: VCO supplementation attenuated cognitive decline with a more positive impact on non-cycling rodents suggesting a beneficial effect on brain health in females in menopausal transition.