Inhalation of Patchouli (Pogostemon CablinBenth.) Essential Oil Improved Metabolic Parameters in Obesity-Induced Sprague Dawley Rats

Abstract

This study investigated effects of patchouli essential oil (PEO) inhalation on metabolic parameters. First, to characterize aromatic compounds in PEO, solid-phase microextraction-gas chromatography/mass spectrometric detection was employed in which 19 aromatic compounds were identified. In GC-olfactometry analysis, linalool,alpha-patchoulene, and beta-patchoulene were found to be the constituents exhibiting the highest similarity to the aromatic compounds in patchouli. In an animal experiment using Sprague Darley rats, groups with PEO inhalation had a reduced food intake compared to the control group. Additionally, body weight was lower in the obesity-induced animal model exposed to PEO inhalation than the group without PEO. However, we found no significant difference in organ weights between groups. In our serum analysis, high-density lipoprotein cholesterol was significantly higher in the PEO inhalation groups, while low-density lipoprotein cholesterol content was highest in the positive control group, suggesting that inhalation of the aromatic compounds present in patchouli may improve cholesterol profile. In addition, leptin levels were reduced in the groups treated with PEO inhalation, which explains the differences in food intake and body weight gains. Last, animal groups exposed to PEO inhalation showed a relatively lower systolic blood pressure which suggests that inhalation of PEO (or aromatic compounds therein) may assist in regulating blood pressure. Collectively, our data demonstrate that the inhalation of PEO influenced certain markers related to metabolic diseases, hence provide basic data for future research as to preventive/therapeutic applications of PEO as well as their aromatic constituents.