Effects of Inhalation of Essential Oil From Pelargonium graveolens on the Autonomic Nervous System of Awake Mice

Autonomic nervous system disorders have many causes, and thus, no effective remedy for these disorders has been established. In this study, we conducted animal experiments with essential oil from Pelargonium graveolens (EOPG, geranium essential oil), which may regulate the autonomic nervous system. EOPG was administered to awake mice by inhalation. Heart rate variability (HRV) was analyzed from the pulse wave of the mice on an elevated platform, and the ratio of sympathetic to parasympathetic nerve activity was determined. The results showed that inhalation of EOPG did not affect the heart rate but made activity of the parasympathetic nervous system dominant. This effect was thought to be due to linalool, a component of EOPG that was transferred into the brain and body.