The Effect Of Wild Yam (Dioscorea Villosa) Tincture On Memory And Learning In Mice

Abstract

In this work, the effect of orally administered tincture of wild yam (Dioscorea villosa) on learning and memory in mice at different ages (young mature, middle aged and elderly) has been studied. To the best of the researcher‟s knowledge, this kind of study has not been done before. The wild yam tincture was administered to the test animals by oral gavage. FELASA guidelines were adhered to in all the experiments. Forty male swiss albino mice were at first randomly allocated into two age cohorts (n=20): ages 3 – 6 months (young mature) and 10 – 14 months (middle age). Each cohort was further divided into a control and test group (n=10 each). The old age cohort evolved when the middle-aged animals reached old age (18 – 24 months) after eight months of the experiment period. The animals were subjected to learning and memory tests. using the T-Maze. Long term memory (reference memory) in the mice was assessed using a left – right discrimination task in a T- maze apparatus. Short term memory (working memory in rodents) was assessed using T-maze forced alternation task. Behavioral flexibility was tested by the reversal learning while memory retention was assessed by the delayed alternation task. For each test four parameters were evaluated: Correct Response (%), Latency (sec), Distance Travelled (cm) and by number of Omission Errors. In this study the effective food reward (bait) used was a breakfast cereal “Kellogg‟s Honey Loops”. Data was analyzed using STATA version 11 software, using independent t-test and results presented as mean ± standard error of means (SEM). The significance level was P<0.05. Motivation was measured by reduction in omission errors. The test and control mice showed no significant difference in memory tests before wild yam tincture was administered. After administration of wild yam tincture the young mature and middle age test mice showed increased learning ability and improved memory: The old age mice showed improved learning and motivation. The young mature, middle age and old age test mice showed statistically insignificant difference from the control mice in behavioral flexibility. The middle age and old age mice showed enhanced learning and better memory than the control mice. The middle age mice showed enhanced memory retention. Old age mice showed no significant memory retention. This study recommends that further studies be undertaken to explore the benefits of wild yam in human volunteers considering that wild yam root tincture. capsules and creams and other root preparations are already widely used as food supplements in Chinese and Western Alternative/Complimentary medicine for other purposes rather than the enhancement of memory and learning. Despite the seriousness of Age-Related Dementia and its accompanying severe memory loss.