Comparative Effects of Taurine and Vitamin E in Acetaminophen-Induced Oxidative Stress on Learning and Memory in Male Wistar Rats

Stress is an integral part of human life; stressful events exert deleterious effects on normal (physiological) functions, leading to the pathogenesis of diseases. Stress alters cognition, learning, memory and emotional responses, resulting in mental disorders like depression and anxiety. The comparative effect of taurine (TAU) and vitamin E (VIT E) was evaluated on learning and memory in acetaminophen-induced oxidative stress in male Wistar rats. Methods Twenty animals weighing (100-120 g) were divided into four groups (A-D) of five rat each. Animals in Group A (control) received 0.5 ml of distilled water only while those in Group B received 100 mg/kg of acetaminophen (ACE) only. Animals in Group C received 100 mg/kg of taurine plus ACE while those in Group D received 0.5ml of Vitamin E plus ACE. The administration was done once daily for sixty days during which learning and memory of the animals were assessed using elevated plus maze and novel object recognition for rats. Results Animals in Groups A, B, C and D were able to locate the closed arm at an average of 41.0 ± 13.2 s, 67.0 ± 13.5 s, 56.3±16.6 s and 32.2± 12.1 s respectively. During the training phase, the TAU + ACE animals explored the object presented to them more (67.99 %) compared with the control and other groups. The VIT E + ACE animals have the least percentage (51.94%) in exploring the novel object that was presented to them. During the consolidation phase, the control group explored the novel object presented to them more (75.62%) when compared with the other groups. The VIT E + ACE animals have the least percentage (64.15%) in exploring the novel object that was presented to the animals. Conclusion Available evidence from this study showed that animals in acetaminophen and control groups were able to explore the elevated plus maze faster than the taurine plus acetaminophen and vitamin E plus acetaminophen groups. It also demonstrated that TAU and VIT E have protective effects on acetaminophen-associated learning and memory impairment in male rats which might be elucidated by antioxidative effects, facilitation of neurotransmitter activity and secretion of the hormone corticosterone.