Effect of inhalation of isomers, (+)-α-pinene and (+)-ß-pinene on human electroencephalographic activity according to gender difference

Introduction: Pinenes are the most abundant components in the essential oils of various plant species. (+)-alpha-Pinene and (+)-ss-pinene are bicyclic monoterpene hydrocarbons with different fragrance qualities. The present study was carried out to investigate the effect of inhalation of isomeric aroma components, (+)-alpha-pinene and (+)-ss-pinene on human electroencephalographic ( EEG) activity according to gender difference. Methods: In this study, the EEG activity was evaluated by the measurement of EEG power spectrum in healthy participants-10 women and 10 men. The EEG readings were recorded using QEEG-8 system from 8 scalp positions of the International 10-20 System. Results: The results indicated that the inhalation of (+)-alpha-pinene and (+)-ss-pinene produced different EEG power spectrum changes as well as affect different brain regions. The gender difference played a major role in the EEG activity of both the components. Women highly responded to both the compounds when compared with men. In women, absolute alpha, absolute beta and absolute high beta activities significantly (P < 0.05) increased during the inhalation of (+)-alpha-pinene. In the case of (+)-ss-pinene, absolute fast alpha and absolute high beta activities also significantly increased. Whereas in men, significant decrease of absolute waves such as theta, beta, low beta and high beta were observed during the inhalation of (+)-alpha-pinene but there were no significant changes in the absolute waves by (+)-ss-pinene. Conclusion: The different EEG activities of these isomers might be due to the different fragrance quality and structural arrangement of the components.