Effect of inhalation of essential oil from Inula helenium L. root on electroencephalographic (EEG) activity of the human brain

Introduction: In traditional systems of medicine, Inula helenium root is widely used for the management of various ailments. The present work investigates the effect of inhalation of essential oil from the root of I. helenium on electroencephalographic (EEG) activity of the human brain.

‍Methods: The effect of inhalation of I. helenium essential oil on EEG activity was evaluated by the measurement of the EEG power spectrum in 20 healthy participants. The EEG spectrum values were recorded using QEEG-8 system from 8 ground electrodes according to the International 10–20 System.

Results: The results showed that the inhalation of essential oil of I. helenium produced significant changes in the EEG power spectrum values. The reduction of absolute theta (all the regions except T3), beta (Fp1) and mid beta (P4) and relative theta (Fp1, Fp2, F3 and F4) waves were observed during the inhalation. Whereas, the ratio of SMR to theta (Fp1 and P4), SMR$mid beta to theta (Fp1) and spectral edge frequency 50% of alpha (P4) significantly increased during the inhalation of I. helenium essential oil.

Conclusion: The changes in EEG values due to the inhalation of essential oil of I. helenium root may enhance the alertness state of the brain and could be used for the treatment of psychophysiological disorders.