Clinical Studies on Anxiolytic “Anxiety Inhibiting” Properties of Essential Oils
1. ORANGE OIL (Citrus Sinensis):
J Altern Complement Med. 2012 Aug;18(8):798-804. doi: 10.1089/acm.2011.0551. Epub 2012 Jul 31.
Effect of sweet orange aroma on experimental anxiety in humans.
The objective of this study was to evaluate the potential anxiolytic [anxiety-inhibiting] effect of sweet orange (Citrus sinensis) aroma in healthy volunteers submitted to an anxiogenic situation.
Forty (40) male volunteers were allocated to five different groups for the inhalation of sweet orange essential oil (test aroma: 2.5, 5, or 10 drops), tea tree essential oil (control aroma: 2.5 drops), or water (nonaromatic control: 2.5 drops). Immediately after inhalation, each volunteer was submitted to a model of anxiety, the video-monitored version of the Stroop Color-Word Test (SCWT).
Psychologic parameters (state-anxiety, subjective tension, tranquilization, and sedation) and physiologic parameters (heart rate and gastrocnemius electromyogram) were evaluated before the inhalation period and before, during, and after the SCWT.
Unlike the control groups, the individuals exposed to the test aroma (2.5 and 10 drops) presented a lack of significant alterations (p>0.05) in state-anxiety, subjective tension and tranquility levels throughout the anxiogenic situation, revealing an anxiolytic activity of sweet orange essential oil. Physiologic alterations along the test were not prevented in any treatment group, as has previously been observed for diazepam.
Although more studies are needed to find out the clinical relevance of aromatherapy for anxiety disorders, the present results indicate an acute anxiolytic activity of sweet orange aroma, giving some scientific support to its use as a tranquilizer by aromatherapists.
2. BERGAMOT (Citrus bergamia)
Forsch Komplementmed. 2015;22(1):43-9. doi: 10.1159/000380989. Epub 2015 Feb 19.
Effects of Bergamot ( Citrus bergamia (Risso) Wright & Arn.) Essential Oil Aromatherapy on Mood States, Parasympathetic Nervous System Activity, and Salivary Cortisol Levels in 41 Healthy Females.
Bergamot essential oil (BEO) is commonly used against psychological stress and anxiety in aromatherapy. The primary aim of the present study was to obtain first clinical evidence for these psychological and physiological effects. A secondary aim was to achieve some fundamental understanding of the relevant pharmacological processes.
Endocrinological, physiological, and psychological effects of BEO vapor inhalation on 41 healthy females were tested using a random crossover study design. Volunteers were exposed to 3 experimental setups (rest (R), rest + water vapor (RW), rest + water vapor + bergamot essential oil (RWB)) for 15 min each. Immediately after each setup, saliva samples were collected and the volunteers rested for 10 min. Subsequently, they completed the Profile of Mood States, State-Trait Anxiety Inventory, and Fatigue Self-Check List. High-frequency (HF) heart rate values, an indicator for parasympathetic nervous system activity, were calculated from heart rate variability values measured both during the 15 min of the experiment and during the subsequent 10 min of rest. Salivary cortisol (CS) levels in the saliva samples were analyzed using ELISA.
CS of all 3 conditions R, RW, and RWB were found to be significantly distinct (p = 0.003). In the subsequent multiple comparison test, the CS value of RWB was significantly lower when compared to the R setup. When comparing the HF values of the RWB setup during the 10 min of rest after the experiment to those of RW, this parameter was significantly increased (p = 0.026) in the RWB setup for which scores for negative emotions and fatigue were also improved.
These results demonstrate that BEO inhaled together with water vapor exerts psychological and physiological effects in a relatively short time. © 2015 S. Karger GmbH, Freiburg.
Front Pharmacol. 2015 Mar 2;6:36. doi: 10.3389/fphar.2015.00036. eCollection 2015.
Citrus bergamia essential oil: from basic research to clinical application.
Citrus bergamia Risso et Poiteau, also known as "Bergamot," is a plant belonging to the Rutaceae family, defined as a hybrid of bitter orange and lemon. It is an endemic plant of the Calabria region (Italy). Bergamot fruit is primarily used for the extraction of its essential oil (bergamot essential oil: BEO), employed in perfume, cosmetics, food, and confections. The aim of this review was to collect recent data from the literature on C. bergamia essential oil and, through a critical analysis, focus on safety and the beneficial effects on human health. Clinical studies on the therapeutic applications of BEO exclusively focus on the field of aromatherapy, suggesting that its use can be useful for reducing anxiety and stress.
Phytother Res. 2011 Jun;25(6):858-62. doi: 10.1002/ptr.3325. Epub 2010 Nov 23.
Acute effects of bergamot oil on anxiety-related behaviour and corticosterone level in rats.
Bergamot essential oil (BEO), Citrus aurantium subsp. bergamia (Risso) Wright & Arn. (Rutaceae), is used widely in aromatherapy to reduce stress and anxiety despite limited scientific evidence. A previous study showed that BEO significantly increased gamma-aminobutyric acid levels in rat hippocampus, suggesting potential anxiolytic properties. The aim of this study was to investigate the effect of BEO (1.0%, 2.5% and 5.0% w/w) administered to rats on both anxiety-related behaviours (the elevated plus-maze (EPM) and hole-board tests) and stress-induced levels of plasma corticosterone in comparison with the effects of diazepam. Inhalation of BEO (1% and 2.5%) and injection of diazepam (1 mg/kg, i.p.) significantly increased the percentage of open arm entries on the EPM. The percentage time spent in the open arms was also significantly enhanced following administration of either BEO (2.5% and 5%) or diazepam. Total arm entries were significantly increased with the highest dose (5%), suggesting an increase in locomotor activity. In the hole-board test, 2.5% BEO and diazepam significantly increased the number of head dips. 2.5% BEO and diazepam attenuated the corticosterone response to acute stress caused by exposure to the EPM. In conclusion, both BEO and diazepam exhibited anxiolytic-like behaviours and attenuated HPA axis activity by reducing the corticosterone response to stress.
Biol Pharm Bull. 2013;36(10):1608-14.
Inhalation of the essential oil of Piper guineense from Cameroon shows sedative and anxiolytic-like effects in mice.
The aromatherapeutical potential of Piper guineense essential oil was investigated in mice via inhalation administration, and the active compounds were identified. An open field test and light/dark transition test were used to evaluate the sedative and anxiolytic activities of this essential oil, respectively. P. guineense essential oil showed significant sedative activity at an effective dose of 4.0 × 10(-5) mg per cage compared to the control group. It also showed potent anxiolytic effect at a dose of 4.0 × 10(-6) mg per cage. The main compounds of P. guineense essential oil were linalool (41.8%) and 3,5-dimethoxytoluene (10.9%). These two main compounds were shown to play a major role in the sedative activity of P. guineense essential oil. These results suggest that inhalation of P. guineense essential oil might induce a mild tranquilizing effect.
Nat Prod Commun. 2011 Nov;6(11):1769-74.
Interspecies comparison of chemical composition and anxiolytic-like effects of lavender oils upon inhalation.
Essential oils have traditionally been used for decades to alleviate the symptoms of various mental problems. In terms of anxiolytic-like properties, lavender oil is probably the most commonly used and best-studied essential oil. Although there is compositional variance among the oils extracted from different origins, there have been few studies performed to date to investigate how these differences affect the expression of anxiolytic-like activity. This paper discusses the interspecies differences and contributions of the main constituents in the expression of anxiolytic-like effects upon inhalation, as assessed in mice by the elevated-plus maze test, by comparing the essential oils from six different species of Lavandula. The results showed qualitative and quantitative variations in the tested oils, which results in significant differences in their anxiolytic-like activities. Our findings also suggest that linalyl acetate (LA) works synergistically with linalool (LO) and that the presence of both LA and LO is essential for the whole oil to work as an inhaled anti-anxiety agent.
**Please note: the top 2 compounds our Lavender are: linalyl acetate (LA) and linalool (LO). As this research study indicates, not all lavender essential oils contain these two compounds. But because our Lavender is grown in the wild at 5,000 feet in elevation, in France. And because it’s fully pure… that’s why the LA and LO content is so high in Be Young’s Lavender.**
Disclaimer: These statements have not been evaluated by the FDA and are not intended to diagnose, treat, cure or prevent any disease.