2022.07.27

Anxiolytic effect and tissue distribution of inhaled Alpinia zerumbet essential oil in mice. Nat Prod Commun. 2010 

#Tadaaki Satou 

#AZEO inhalation was started 90 min prior to the LD, OF and EPM

#Tissue distribution

• Alpha-Pinene accumulated in the brain at almost the same rate as in the liver. However, the oil components chiefly accumulated in the kidney. 
• After the observations ended on the third day (EPM), the mice were euthanized by carbon dioxide gas and the internal organs (blood, liver, kidney, brain) collected. These were processed without drainage and extracted with n-hexane by sonication. The extracts were analyzed by GC-MS under the above-mentioned conditions. 

The GABAergic system contributes to the anxiolytic-like effect of essential oil from Cymbopogon citratus (lemongrass). J Ethnopharmacol. 2011 

#vehicle 

• The behavioral data did not differ among the animals that received the three vehicle solutions – Tween (TW), saline and water – (data not shown), which justified our choice to include only the TW control group data for comparison. 

#Schedule

• For the single treatment, mice were treated 30 min before experimental procedures, whereas for long-term treatment (WHO, 1993), animals were treated with the EO for 21 days and exposed to the experimental procedure 30 min after the last treatment. For evaluation of antidepressant activity, mice were treated three times within the 24 h before the experimental procedure. 

#Action mechanism

• To address a possible contribution from the GABAergic system, mice were co-administered DZP (standard drug. 1 mg/kg, i.p.) or the EO (10 mg/kg, p.o.) 30 min before the test and then were given FLU (2 mg/kg, i.p.) 15 min before testing. 
• To evaluate possible interference from the serotonergic system, animals were pretreated with WAY (0.1 mg/kg, i.p.) and 15 min afterwards, received the EO (10 mg/kg) or the standard drug DZP (1 mg/kg); the experimental procedure was carried out 30 min after the last drug treatment.

#Rota-rod test

• there were no significant differences between groups after either acute or repeated treatments with the EO in the rota-rod test.

#Sleep induced by diethyl-ether (SID)

• The effectiveness of the EO was measured by its capacity to reduce the latency to sleep and/or to increase the duration of sleep without interfering with hepatic metabolism (Tsuji et al., 1996). Thirty minutes after the treatments with EO (500, 1000 or 1500 mg/kg), animals were induced to sleep by inhalation of diethyl-ether in a 3-L flask. Each mouse was placed individually in a cylindrical glass chamber saturated for 20 min with vapor delivered from 5 ml of diethyl-ether absorbed on a piece of cotton bound in the coiled cap of the flask. Each mouse was left there for 60 s after loss of its postural reflex – sleep latency was defined as time until loss of the postural reflex – and then was withdrawn and placed in an individual cage to record the time to recover the postural reflex (sleep duration) (Héllión-Ibarrola et al., 2006).

Neuroprotective and Anti-Aging Potentials of Essential Oils from Aromatic and Medicinal Plants. Front Aging Neurosci. 2017 

A Systematic Review of the Anxiolytic-Like Effects of Essential Oils in Animal Models. Molecules 2015.