Effects of fragrance inhalation of essential oil on control of blood pressure and muscle sympathetic nerve activity in humans

Abstract

AimsWe recently reported that inhalation of fragrance of Grapefruit essential oil increased blood pressure (BP) while that of Marjoram essential oil decreased BP in humans. In this study, we investigated the effects of fragrance inhalation of Grapefruit and Marjoram essential oil on control of BP and muscle sympathetic nerve activity (MSNA), and also cardiovagal and sympathetic baroreflex function.MethodsThirteen healthy subjects participated in each trial of this study. The experiment was performed in the supine position. Subjects breathed blank air through a face mask for 10 min as baseline. Then, they inhaled air with the fragrance of Grapefruit or Marjoram essential oil from Douglas bags for 10 min. Throughout the trial, MSNA (peroneal nerve, microneurography), beat‐by‐beat heart rate and BP, and breath‐by‐breath respiratory variables were recorded continuously.ResultsBy inhalation of the fragrance of Grapefruit essential oil, diastolic BP increased at 8 to 10 min of inhalation (64 ± 9 mmHg) compared to baseline (62 ± 9 mmHg), whereas MSNA burst rate remained unchanged at the period of inhalation (14.2 ± 8.5 bursts/min) from baseline (13.2 ± 7.0 bursts/min). Cardiovagal (10.8 ± 5.6 vs. 11.9 ± 9.6 ms/mmHg) or sympathetic baroreflex sensitivity (−0.84 ± 0.61 vs. −1.03 ± 0.78 au/mmHg) remained unchanged from baseline at the period of inhalation. On the other hand, by inhalation of the fragrance of Marjoram essential oil, diastolic BP increased at 8 to 10 min of inhalation (61 ± 7 mmHg) compared to baseline (60 ± 8 mmHg) against our previous studies, while MSNA burst rate remained unchanged at the period of inhalation (14.0 ± 8.5 bursts/min) from baseline (12.0 ± 9.4 bursts/min). Cardiovagal (12.0 ± 7.3 vs. 14.9 ± 13.1 ms/mmHg) or sympathetic baroreflex sensitivity (−1.06 ± 0.65 vs. −0.97 ± 0.54 au/mmHg) remained unchanged from baseline at the period of inhalation. Heart rate and respiratory variables remained unchanged in both trials.ConclusionsThe fragrance stimulation of Grapefruit essential oil increased BP without increase in MSNA nor modulating cardiovagal and sympathetic control of BP in humans.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.