Neurochemical Impact of the Aqueous Extract of Vernonia amygdalina and Talinum triangulare on Learning and Memory in Male Wistar Rats

摘要

Background: Nutrition affects virtually everything in the life of an organism, including cognitive abilities, at the level of learning and memory. The brain being a metabolically active tissue is prone to lipid peroxidation which affects cognitive functions. Despite the well documented nutritional and medicinal values of Vernonia amygdalina (bitter leaf) and Talinum triangulare (water leaf), their neurochemical impact through learning and memory are yet to be fully elucidated. Objective: The aim of the present study was to evaluate the neurochemical impact of the aqueous extracts of Vernonia amygdalina and Talinum triangulare on cognitive function in male Wistar rats. Methods: Twenty one male Wistar rats (175.83 ± 6.92g), were randomly assigned into three groups A, B, and C (n=7 per group); Vernonia amygdalina , Talinum triangulare and Control (Saline) groups respectively. They were treated with 2ml/100g BW of the extracts every other day for thirty days. Twenty four (24) hours after the last administration, rats were subjected to learning and memory assays for one week, thereafter, brain tissue was homogenized and assayed for cholinergic activity, while blood samples were taken and used for biochemical parameters. Results: There was a significant increase in body weight of treated rats relative to control. Vernonia group A; 176.5±4.6, Talinum group B; 161.8±2.9 and the Control group C; 150.8±16.5g respectively (p < 0.05). The treated rats spent more time in the light compartment of the Shuttle box in the learning and memory assays. Both extracts exhibited hypoglycemic effect, however, only Vernonia enhanced a significant increase in brain acetylcholinesterase (AChE) activity. Conclusion: Vernonia amygdalina and Talinum triangulare enhanced learning and memory via modulation of brain cholinergic neurotransmission. Hence, as a future directed study, their neuroprotective effect in brain cell death inhibition is recommended.