P.2.20 c-fos mRNA expression within the ratbrain after exposure to the elevated plus maze: effect of prior treatment with anxiogenic and anxiolytic drugs

Abstract

Essential oil from Cananga odorata (ylang-ylang essential oil, YYO) is usually used in reducing blood pressure, improving cognitive functioning in aromatherapy in human. Few reports showed its effect on anxiety behaviors.To investigate the anxiolytic effects of YYO exposure on anxiety animal models, determine the major active constituents and investigate the change of neurotransmitters after odor exposure.ICR mice were subjected to three anxiety models including open field, elevated plus maze and light-dark box tests after acute and chronic YYO exposure. Main constituents of YYO were defined using GC/MS. These compounds were then tested on the male mice separately on three anxiety models. The monoamines neurotransmitters and their metabolites were analyzed after acute odor exposure and elevated plus maze test.YYO exposure only showed significant anxiolytic effect on the male mice. It increased the time that mice visited open arms and light box area in elevated plus maze and light-dark box tests after acute and chronic YYO exposures. Three main constituents of YYO, benzyl benzoate, linalool and benzyl alcohol showed anxiolytic effect on the male mice individually. YYO exposure brought changes of neurotransmitters on the male mice more significantly than the female mice. It decreased the dopamine (DA) concentration in the striatum and increased the 5-hydroxytryptamine (5-HT) concentration in the hippocampus of the male mice. The major constituent benzyl benzoate changed neurotransmitters concentration in accordance with the YYO. Moreover, it decreased the ratio of 5-HIAA/5-HT in the hippocampus.Both acute and chronic YYO exposure showed anxiolytic effect on the male mice. YYO and its major constituent benzyl benzoate might act on the 5-HTnergic and DAnergic pathways.