ABSTRACT
Ascorbic acid (AA) and Garcinia Kola (GK) are substances believed to affect the central mechanism of sleep. This study aimed to evaluate and compare the thiopental sodium-induced sleep in Wistar rats in pretreated doses of separately administered ascorbic acid and aqueous extract of Garcinia kola. It measured the onset and duration of ascorbic acid and Garcinia kola pretreatment on thiopental sodium-induced sleep. 65 adult male Wistar rats of comparable weight between the ranges of 149-165g were used for this study. The rats were arranged into 13 groups (12 groups for experiment + 1 group for control) by the duration of the administration and treatment doses of ascorbic acid and ethanolic extract of Garcinia kola with 5 rats per group. Group A served as control, groups B, C, D, E, F, and G received 5mg, 10mg, 20mg, 40mg, 80mg and 160mg of Garcinia kola extract respectively. Animals in group A which served as control, received 40 mg/Kg of thiopental sodium. Groups B, C, D, E, F, and G were pre-treated with doses of ethanolic extract of Garcinia kola before administration of doses of thiopental sodium 5 minutes later. Groups H, I, J, K, L and M were similarly treated as Groups B, C, D, E, F, and G animals with doses of ascorbic acid solution before thiopental sodium administration. These doses were administered intraperitoneally using a syringe. The rats were kept in clear cages and because of this, it was easy to use a stopwatch to note when the induced sleep started and ended in each scenario. Data obtained was analyzed using GraphPad statistical software version 9.5 and results analyzed were presented in mean ±SEM. A two-way ANOVA was conducted to assess the effects of Garcinia kola and Ascorbic acid pretreatment on sleep onset and duration in Wistar rats. A post-hoc Tukey’s test was utilized to compare the means between different treatment groups. A P-value less than 0.05 was considered statistically significant. Results showed statistically significant increase (P>0.05) in sleep onset after GK administration across all doses compared with the control group, a statistically significant decrease (P>0.05) in sleep duration after GK administration of 5mg/kg, 10mg/kg, 20mg/kg, 80mg/kg and 160mg/kg doses when compared with the control group, a statistically significant increase (P>0.05) in sleep duration after GK administration of 40mg/kg dose when compared with the control, a statistically significant decrease (P>0.05) in sleep duration after AA administration of 10mg/kg, 20mg/kg, 40mg/kg, 80mg/kg and 160mg/kg doses when compared with the control group, a statistically significant decrease (P>0.05) in sleep duration after AA administration of 5mg/kg dose when compared with the control group, a statistically significant increase (P>0.05) in sleep duration after AA administration of 20mg/kg, 80mg/kg and 160mg/kg doses when compared with the control group, a statistically significant decrease (P>0.05) in sleep onset after AA administration of 5mg/kg, 10mg/kg, 20mg/kg 40mg/kg, 80mg/kg, and 160mg/kg dose when compared with the GK group, a statistically significant increase (P>0.05) in sleep duration after AA administration of 5mg/kg, 10mg/kg, 20mg/kg, 80mg/kg, and 160mg/kg dose when compared with the GK group and a statistically significant decrease (P>0.05) in sleep duration after AA administration of 40mg/kg, dose when compared with the GK group. These observations led to the conclusion that Ascorbic acid and Garcinia Kola at specific doses may potentiate sleep and wakefulness respectively by affecting both sleep onset and duration. Thus, it can be concluded that both ascorbic acid and Garcinia Kola probably have definable central nervous system properties because of the modulating effect on sleep as seen in this study.
