Essential Oil Considerations
Essential oil qualities can vary greatly in character ranging from antibacterial, antiviral, anti-inflammatory natures along with immunostimulant with hormonal, glandular, emotional, circulatory, calming effects, a memory and alertness enhancer, that have been documented.1,2 The stimulation properties of these oils are said to lay in their structure which are closely in resemblance with actual hormones.3 The mechanism of their action is said to involve integration of essential oils into a biological signal of the receptor cells in the nose when inhaled. The signal is then transmitted to limbic and hypothalamic regions of the brain via olfactory bulb. These signals cause the brain to release neurotransmitters like serotonin, norepinephrine, etc. to link the nervous system and other body systems to elicit a healing response.4 The olfactory bulb has demonstrated persistent neurogenesis in adults.5 This, coupled with the connections to the limbic system and hippocampus, may point to particular scents and stimulation of the bulb potentially altering cognitive operations of memories or traumas. The matter of essential oils is a common question given it's rise in popularity in recent years. While I do not frequently use them clinically below are a few oils which may be further explored in relation to brain injury.
A study demonstrated bergamot essential oil to reduce neuronal damage caused in vitro by excitotoxic stimuli and that this neuroprotection was associated with prevention of injury-induced engagement of critical death pathways. In addition to preventing reactive oxygen species accumulation and activation of calpain, the bergamot oil seemed to counteract the deactivation of Akt kinase and the consequent activation of glycogen synthase kinase-3β (GSK-3β) . This was hypothesized to be the result of oil monoterpene hydrocarbons.6
Basil is a top note oil which is listed as a nervine, CNS stimulant and adrenal restorative. It is said to increase the guardian Qi, tonify the Kidney Yang and rectify the brain. From these functions it is indicated for concussion, fatigue, exhaustion, nervous depression, anxiety, memory loss, and shock.7
Frankincense is a base note oil that, among other things, is said to act as a nervous restorative, antidepressant, antioxidant and immunostimulant. In herbal form frankincense is known as Ru Xiang and used in Chinese medicine frequently for it's anti-inflammatory, analgesic, and wound healing properties indicated for traumas of many types. As an oil some of it's indications include irritability, restlessness, sensory overstimulation, nightmares, mental confusion or weakness, neurasthenia and menstrual irregularities. It is said to invigorate the Blood and calm the Shen by harmonizing the Yi and Hun.
Vetiver is a base note oil well regarded as having a relaxant or grounding effect in overstimulation conditions. It is listed as being indicated for anxiety, fear, hypersensitivity, overexcitment, delusion, and paranoia. It is also said to reduce basal ganglia and cingulate system hyperfunctioning and resolve temporal lobes dysregulation. Obsessions and compulsions are also listed as being conditions that may benefit. It is said to be a neuroendocrine restorative, assisting in hormonal or central nervous system deficiencies including fatigue, chronic neurasthenia, insomnia, and hysteria. Additionally, it is indicated for a wide range of menstrual concerns. Chinese medical functions are said to include invigorating Blood, tonifying the Blood and essence, augmenting the Qi by tonifying the Spleen, nourishing Kidney Yin, and regulating Heart Qi to harmonize the Shen. A study of it's chemical constituents concluded vetiver oil may suppress inflammatory responses including nitric oxide production and cell apoptosis by regulating the expression of the inflammation-related enzymes heme oxygenase-1, inducible nitric oxide synthase and cyclooxygenase-2 (inducible cyclooxygenase) and the inflammatory cytokines tumour necrosis factor-α, interleukin-1β and interferon-β.8
A top/middle note, lavender oil has been studied and shown to have growing evidence of offering benefit in several neurological disorders. Several animal and human studies suggest anxiolytic, mood stabilizer, sedative, analgesic, and anticonvulsive and neuroprotective properties.9 Rat studies have shown neuroprotective properties on cerebral ischemia/reperfusion injury have been shown to diminish glutamate-induced neurotoxicity10 as well as decreasing neurological deficit scores, infarct size, and the levels of mitochondria-generated reactive oxygen species and attenuated neuronal damage.11 Chinese medical literature lists it's actions as regulating in dysregulation conditions, a relaxant in over stimulation conditions, and mildly euphoric in acute shock conditions; speculating that it may reduces limbic system and basal ganglia hyperfunctioning while resolving temporal lobe dysfunction. In this sense it is indicated for hypomania, PTSD, panic attacks, insomnia, irritability, depression, anxiety, feeling mentally overwhelmed, shock and trauma.
Orange essential oil, a top note, has been found to have CNS depressant-like effects in mice. A study examined the effects on fear memory and immune cell activation in a mouse model of PTSD using Pavlovian Fear Conditioning. Mice showed no difference in freezing up when fear stimuli was introduced but when tested for extinction retention 48 hours later the treatment group experienced a significant decrease in freezing behavior versus control. This suggests that orange oil may affect extinction of fear memories.12
1. K.P. Svoboda, S.G. DeansBiological activities of essential oils from selected aromatic plants
Acta Hort, 390 (1995), pp. 203-209
2. K. Svoboda, J. Hampson, E.A. HunterProduction and bioactivity of essential oils in secretary tissues of higher plants
Proceedings of World Aromatherapy II Conference of National Association for Holistic Aromatherapy (NAHA); Sep 25–28; St. Louis, Missouri, USA (1998), pp. 105-127
3. S.M. Colgate, R.J. MolyneuxBioactive natural products detection, isolation and structural determination
CRC Press, Florida (1933)
4.Babar Ali, Naser Ali Al-Wabel, Saiba Shams, Aftab Ahamad, Shah Alam Khan, Firoz Anwar, Essential oils used in aromatherapy: A systemic review, Asian Pacific Journal of Tropical Biomedicine, Volume 5, Issue 8, August 2015, Pages 601-611, ISSN 2221-1691, https://doi.org/10.1016/j.apjtb.2015.05.007.
5. Altman, J. (1969), Autoradiographic and histological studies of postnatal neurogenesis. IV. Cell proliferation and migration in the anterior forebrain, with special reference to persisting neurogenesis in the olfactory bulb. J. Comp. Neurol., 137: 433–457. doi:10.1002/cne.901370404
6. Corasaniti MT, Maiuolo J, Maida S, et al. Cell signaling pathways in the mechanisms of neuroprotection afforded by bergamot essential oil against NMDA-induced cell death in vitro. British Journal of Pharmacology. 2007;151(4):518-529. doi:10.1038/sj.bjp.0707237.
7. Holmes, P. (2017). AROMATICA: a clinical guide to essential oil therapeutics;. London: Jessica Kingsley.
8.Chou, S-T, Lai, C-P, Lin, C-C, Shih, Y, Study of the chemical composition, antioxidant activity and anti-inflammatory activity of essential oil from Vetiveria zizanioides, In Food Chemistry, Volume 134, Issue 1, 2012, Pages 262-268, ISSN 0308-8146, https://doi.org/10.1016/j.foodchem.2012.02.131.
9. Koulivand PH, Khaleghi Ghadiri M, Gorji A. Lavender and the Nervous System. Evidence-based Complementary and Alternative Medicine : eCAM. 2013;2013:681304. doi:10.1155/2013/681304.
10.Büyükokuroğlu ME, Gepdiremen A, Hacimüftüoğlu A, Oktay M, The effects of aqueous extract of Lavandula angustifolia flowers in glutamate-induced neurotoxicity of cerebellar granular cell culture of rat pups. J Ethnopharmacol. 2003 Jan; 84(1):91-4.
11. Wang D, Yuan X, Liu T, Liu L, Hu Y, Wang Z, Zheng Q, Neuroprotective activity of lavender oil on transient focal cerebral ischemia in mice. Molecules. 2012 Aug 15; 17(8):9803-17.
12. Effects of Essential Oil on Fear Memory and the Immune Response; A Potential Alternative Therapy for Post-Traumatic Stress Disorder (PSTD) Cassandra Moshfegh, P Swiercz, Lauren Hopkins, Paul J Marvar April 2016, The FASEB Journal. vol. 30 no. 1 Supplement1238.5