Cholinergic cognitive enhancer effect of Salvia triloba L. essential oil inhalation in rats

Objective: Current treatment of Alzheimer’s disease is provided by cholinesterase inhibitors. Salvia triloba L. (syn. Salvia fruticosa Mill.), a species mostly consumed as refreshing herbal tea in traditional medicine, is rich in 1,8-cineole that is known to have cholinesterase inhibiting effects. In this study, we investigated cognitive enhancer effects of S. triloba essential oil inhalation on healthy control rats and rats with scopolamine induced memory impairment. Materials and Methods: S. triloba samples from different geographical locations of Turkey were hydro-distilled and analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). The optimum sample with the highest 1,8-cineole and lowest camphor, α-thujone and β-thujone content was selected. In vitro cholinergic and antioxidant potentials of the selected essential oil were calculated. Cognitive enhancer and anti-amnestic effects of the inhaled essential oil on rats were assessed by means of Morris water maze. The bioavailability of 1,8-cineole in blood of rats was measured by GC-MS. Results: The group that inhaled S. triloba significantly outperformed control group, namely faster achieving peak escape latency performance in Morris water maze. However, S. triloba inhalation failed to restore scopolamine induced learning impairment. Conclusion: In this study, we report positive effects of inhaling S. triloba essential oil as a complementary treatment for supporting cognitive functions.