Daily inhalation of α-pinene in mice: effects on behavior and organ accumulation.

In phytotherapy, essential oils tend to be used daily for a period of days or weeks, rather than in a single application. However, the literature contains very little information on repeated use of essential oils. In this study, we investigated the effects on behavior and the accumulation in the brain and liver of α-pinene, an essential oil component, when inhaled by mice. Animals were individually housed in cages for 1 week. Mice inhaled α-pinene or water vapor (negative control) for 90 min/day for 1 day, 3 days, or 5 days, and they were then submitted to the elevated plus maze test for 10 min. We used gas chromatography with flame ionization detection to quantify concentrations of α-pinene in the brain and liver. There was significant anxiolytic-like activity, which remained constant for the 5 days’ inhalation of α-pinene. On the other hand, the accumulation of α-pinene in the brain and liver peaked on the third day of inhalation. The existence of stress related to the new environment appears to have affected the change in the accumulation of α-pinene in the internal organs, keeping the anxiolytic-like action constant.