In the Japanese Journal of Oleo Science (‘oleo’ meaning ‘oil’), scientists published a study titled: “Essential oil from lemon peels inhibit key enzymes linked to neurodegenerative conditions and pro-oxidant induced lipid peroxidation”. What does that even mean? Well, this research supports other studies which have shown inhalation of Lemon and Rosemary essential oils had positive effect on those already diagnosed with dementia4, and supports the possibility of their use a as a possible preventative measure. The full article explained the details well, so read on!
First we’ll review this statement in the title: “Essential oil from lemon peels inhibit key enzymes linked to neurodegenerative conditions”. In the article’s introduction, the authors note: “Recent trends in the management of neurodegenerative conditions, especially Alzheimer’s disease, is to increase brain acetylcholine levels with the use of cholinesterase inhibitors.”
Lemon essential oil research
The authors continue: “This is because in Alzheimer’s disease conditions there is elevated acetylcholinesterase activities which serve to break down the neurotransmitters acetylcholine and butyrylcholine thereby giving rise to symptoms observed in AD (Alzeheimer’s disease).” The study’s results show that the inhibition of both acetylcholinesterase and butyrylcholinesterase occurred in a dose-dependent manner with exposure to Lemon essential oil.
Researchers also state: “In addition, the use of foods rich in antioxidants have been proposed to be beneficial in the management of neurodegenerative conditions because of the high oxygen consumption of the brain cells and neurons (results in greater) attack by reactive oxygen species (free-radicals)”…This study, therefore investigated…antioxidative potential of essential oils from lemon peels.
The results of the study clearly indicate lemon essential oil to have the ability to prevent lipid peroxidation (meaning ‘oxidation of lipids’ or ‘fats’, of which brain cells are significantly made up of). Upon searching “essential oil antioxidant” on pubmed.gov, one can find a many studies which show the antioxidant activities of wide variety of essential oils. Essential oils in general are of a chemically non-polar nature, and for this reason, are absorbed well into lipid (fat) containing organs, such as the brain.
Research Involving Other Essential Oils, Their Inhalation & Enzyme Inhibition
The effect of acetylcholinesterase inhibition has been shown with a wide variety of essential oils, including those from Salvia2 & Pine species3, and Rosemary4. While the conclusion has not been clearly drawn, this may be the reason some studies have shown improved mental acuity (noted from improved test scores) from the inhalation of these oils.
So What Does All This Mean to the Essential Oil Practitioner?
While there has not been established a direct cause and effect relationship between the acetylcholinesterase inhibitition by essential oils, as well as their lipid-peroxidation inhibitory properties to prevention of neurodegenerative diseases, these studies to for the most part suggest this is certainly worth further investigation.
And What Do We Do With These Essential Oils?
Whenever we feel like attention is waning, or we want to feel a little sharper for the tasks we’re undertaking, we’ll diffuse Lemon, or other bright citrus oils (which have similar chemical constituencies) like Grapefruit and Bergamot.
While we cannot say as to whether what seems to be a more clear attention to detail is from the aromas, we sure do feel like we’re able to stay focused on the tasks we’re performing. And this data encourages us to keep using these
Been Enjoying Our Lemon? Science Uncovers this Essential Oil’s Support for the Aging Brain
1.Essential oil from lemon peels inhibit key enzymes linked to neurodegenerative conditions and pro-oxidant induced lipid peroxidation.
Published in: J Oleo Sci. 2014;63(4):373-81. Epub 2014 Mar 5. Authors: Oboh G1, Olasehinde TA, Ademosun AO.
“This study sought to investigate the effects of essential oil from lemon (Citrus limoni) peels on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities in vitro. Antioxidant properties of the oil and inhibition of pro-oxidant-induced lipid peroxidation in rats brain homogenate were also assessed. The essential oil inhibited AChE and BChE activities in a concentration-dependent manner. Furthermore, the essential oil exhibited antioxidant activities as typified by ferric reducing property, Fe(2+)-chelation and radicals [DPPH, ABTS, OH, NO] scavenging abilities. The inhibition of AChE and BChE activities, inhibition of pro-oxidant induced lipid peroxidation and antioxidant activities could be possible mechanisms for the use of the essential oil in the management and prevention of oxidative stress-induced neurodegeneration.”
2. Systematic review of clinical trials assessing pharmacological properties of Salvia species on memory, cognitive impairment and Alzheimer’s disease.
Published in: CNS Neurosci Ther. 2014 Jun;20(6):485-95. doi: 10.1111/cns.12270. Epub 2014 Apr 10th. Authors: Miroddi M1, Navarra M, Quattropani MC, Calapai F, Gangemi S, Calapai G.
“Salvia officinalis L. and Salvia lavandulaefolia L. have a longstanding use as traditional herbal remedies that can enhance memory and improve cognitive functions. Pharmacological actions of S. officinalis and S. lavandulaefolia on healthy subjects and on patients suffering of cognitive decline have been investigated. Aim of this review was to summarize published clinical trials assessing effectiveness and safety of S. officinalis and S. lavandulaefolia in the enhancement of cognitive performance in healthy subjects and neurodegenerative illnesses. Furthermore, to purchase a more complete view on safety of S. officinalis and S. lavandulaefolia, we collected and discussed articles regarding toxicity and adverse reactions. Eight clinical studies investigating on acute effects of S. officinalis on healthy subjects were included in the review. Six studies investigated on the effects of S. officinalis and S. lavandaeluaefolia on cognitive performance in healthy subjects. The two remaining were carried out to study the effects of sage on Azheimer’s disease. Our review shows that S. officinalis and S. lavandulaefolia exert beneficial effects by enhancing cognitive performance both in healthy subjects and patients with dementia or cognitive impairment and is safe for this indication. Unfortunately, promising beneficial effects are debased by methodological issues, use of different herbal preparations (extracts, essential oil, use of raw material), lack of details on herbal products used. We believe that sage promising effects need further higher methodological standard clinical trials.”
3. Acetylcholinesterase and butyrylcholinesterase inhibitory activity of Pinus species essential oils and their constituents.
Published in: J Enzyme Inhib Med Chem. 2010 Oct;25(5):622-8. Authors: Bonesi M1, Menichini F, Tundis R, Loizzo MR, Conforti F, Passalacqua NG, Statti GA, Menichini F.
“This study aimed to investigate the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity of the essential oils from Pinus nigra subsp. nigra, P. nigra var. calabrica, and P. heldreichii subsp. leucodermis. This activity is relevant to the treatment of Alzheimer’s disease (AD), since cholinesterase drugs are currently the only drugs available to treat AD. P. heldreichii subsp. leucodermis exhibited the most promising activity, with IC(50) values of 51.1 and 80.6 microg/mL against AChE and BChE, respectively. An interesting activity against AChE was also observed with P. nigra subsp. nigra essential oil, with an IC(50) value of 94.4 microg/mL. Essential oils were analyzed by GC and GC-MS with the purpose of investigating their relationships with the observed activities. Among the identified constituents, terpinolene, beta-phellandrene, linalyl acetate, trans-caryophyllene, and terpinen-4-ol were tested. trans-Caryophyllene and terpinen-4-ol inhibited BChE with IC(50) values of 78.6 and 107.6 microg/mL, respectively. beta-Phellandrene was selective against AChE (IC(50) value of 120.2 microg/mL).”
4. Effect of aromatherapy on patients with Alzheimer’s disease.
From: Psychogeriatrics. 2009 Dec;9(4):173-9. Authors: Jimbo D1, Kimura Y, Taniguchi M, Inoue M, Urakami K.
“Recently, the importance of non-pharmacological therapies for dementia has come to the fore. In the present study, we examined the curative effects of aromatherapy in dementia in 28 elderly people, 17 of whom had Alzheimer’s disease (AD).”
“After a control period of 28 days, aromatherapy was performed over the following 28 days, with a wash out period of another 28 days. Aromatherapy consisted of the use of rosemary and lemon essential oils in the morning, and lavender and orange in the evening. To determine the effects of aromatherapy, patients were evaluated using the Japanese version of the Gottfries, Brane, Steen scale (GBSS-J), Functional Assessment Staging of Alzheimer’s disease (FAST), a revised version of Hasegawa’s Dementia Scale (HDS-R), and the Touch Panel-type Dementia Assessment Scale (TDAS) four times: before the control period, after the control period, after aromatherapy, and after the washout period.”
“All patients showed significant improvement in personal orientation related to cognitive function on both the GBSS-J and TDAS after therapy. In particular, patients with AD showed significant improvement in total TDAS scores. Result of routine laboratory tests showed no significant changes, suggesting that there were no side-effects associated with the use of aromatherapy. Results from Zarit’s score showed no significant changes, suggesting that caregivers had no effect on the improved patient scores seen in the other tests.”
“In conclusion, we found aromatherapy an efficacious non-pharmacological therapy for dementia. Aromatherapy may have some potential for improving cognitive function, especially in AD patients.”