Effect of Lemongrass Aroma on Experimental Anxiety in Humans

Objectives: The objective of this study was to evaluate the potential anxiolytic effect of lemongrass ( Cymbopogon citratus ) aroma in healthy volunteers submitted to an anxiogenic situation. Design: Forty male volunteers were allocated to four different groups for the inhalation of lemongrass essential oil (test aroma: three or six drops), tea tree essential oil (control aroma: three drops), or distilled water (nonaromatic control: three drops). Immediately after inhalation, each volunteer was submitted to an experimental model of anxiety, the video-monitored version of the Stroop Color-Word Test (SCWT). Outcome measures: Psychologic parameters (state anxiety, subjective tension, tranquilization, and sedation) and physiologic parameters (heart rate and gastrocnemius electromyogram activity) were evaluated before the inhalation period and before, during, and after the SCWT. Results: Individuals exposed to the test aroma (three and six drops), unlike the control groups, presented a reduction in state anxiety and subjective tension, immediately after treatment administration. In addition, although they presented an anxious response to the task, they completely recovered from it in 5 min, unlike the control groups. Physiologic alterations along the test were not prevented by any treatment, in the same way as has previously been observed for diazepam. Conclusions: Although more investigations are necessary to clarify the clinical relevance of lemongrass essential oil as an anxiety treatment, this work shows that very brief exposure to this aroma has some perceived anxiolytic effects.