Comparison of Alphapinene and Donpezil Effects on Passive Avoidance Memory in Adult Male Rats

Background and Objectives: Alphapinene as one of the most important Components of essential oils, which has antioxidant and anti-cholinesterase activities. Oxidative stress directly affects the function of the brain and causes memory impairment. In this research, the effect of alphapinene on passive avoidance memory and oxidative stress, was investigated in comparison with donepezil.   Methods: In this study, 50 male Wistar rats were divided into 5 groups: control, sham (received alphapinene solvent), groups received 2 and 4mg/kg alphapinene, and group that received donepezil. The drugs were administered intraperitoneally for two weeks. At the end of the treatment, passive avoidance memory in animals, was assessed using the shuttle box test, level of malondialdehyde, total thiol concentration in blood, and hippocampal tissue as oxidative stress indices. One-way ANOVA and Tukey's post hoc tests, were used to determine the difference between the groups.   Results: Memory significantly increased in the group receiving donepezil (p<0.01), and in the groups that received alphapinene (doses, 2 and 4mg/kg), memory significantly increased compared to the control group (p<0.001). A significant increase was observed in the dose of 4mg/kg alphapinene compared to the donepezil group (p<0.001). The concentration of malondialdehyde in the hippocampus tissue significantly decreased in the group received the dose of 4mg/kg compared to the control group. Moreover, the total amount of hippocampal thiol showed a significant increase in the group receiving alphapinene (dose, 4mg/kg) compared to the control group (p<0.05).   Conclusion: The results of this study showed that alphapinene at dose of 4mg/kg had the highest effect on memory improvement even compared to the donepezil group and also decreased the oxidative stress indices due to its antioxidant property.