Essential oils

November 11/18/21, 2021from admin

Essential oils are volatile, aromatic compounds and the pure essence of plant extracts. The plants undergo a special distillation process in which the essential oil is separated from its plant component.

We encounter essential oils as part of herbs and spices every day in our everyday lives: whether it is cinnamon on our morning porridge, a cup of peppermint tea in the afternoon or basil on our spaghetti in the evening – we always consume volatile essential oil compounds.

Diverse application possibilities

Essential oils are also used specifically in their concentrated form as dietary supplements and topically, d.h. applied to the skin. The most common form, however, is inhalation, in which the oil is inhaled using steam.

Essential oils are also often used in cooking or baking as a substitute for fresh or dried spices and herbs—for example, to add a particularly intense orange or lemon flavor to baked goods. However, the dosage should be very careful, as the aroma is significantly more concentrated and therefore more intense than with conventional spices.

The addition of essential oils to drinks such as tea, smoothies, water or milk is becoming increasingly popular.

When essential oils are ingested as part of food or concentrated as a dietary supplement, they enter the bloodstream via the gastrointestinal tract. Essential oils are fat-soluble, so they are easily transported to all organs of the body, including the brain. Then, like everything we consume, essential oils are metabolized by the liver and other organs and ultimately excreted.

The external, topical application of essential oils has also proven effective over many years. For example, adding a few drops of oil to a warm bath or as a hot or cold compress by soaking a towel in water, adding essential oils, and then applying it to the desired area. Adding essential oils to a lotion or moisturizer, which is then applied to the skin, is also a proven way to enjoy the benefits of essential oils. Of course, sensitive areas such as the skin around the eyes, the eyes, and the inner ears, as well as broken skin, should be avoided.

The biochemistry behind essential oils: health effects and connections

But in addition to the emotional component, which anyone who has ever come into contact with high-quality essential oils can immediately understand, there are also more and more scientific studies that examine the health benefits of essential oils on a biochemical level.

The nose, with its approximately 350 olfactory receptors, naturally plays a crucial role in the perception of scents. Biochemically, the messenger molecule cAMP plays an important role, converting the olfactory information triggered by the olfactory receptors in the olfactory sensory cells into an electrical impulse that is transmitted to the brain via the central nervous system.

But odorant receptors are found not only in the nose, but in all cells of the body, for example, in fatty tissue, but also in organs like the lungs, heart, or kidneys, where one might not normally expect them. Outside of the nose, however, these odorant receptors have nothing to do with "smell" in the true sense, so a term like "chemoreceptors" would probably be more appropriate. If a molecule activates one of these receptors, it can stimulate the cells to release messenger substances, divide, or move.According to research by Professor Klatt from the Ruhr University Bochum, these receptors also influence cell death – which could open up exciting possibilities, for example, in the context of cancer therapies.

Between 5 and 80 different types of odorant receptors can be found in each tissue. These odorant receptors control a multitude of different signaling pathways that can have very different effects at the cellular level:

For example, an odorant receptor for violet scent inhibits cell growth in the pigment cells of the skin, while it can promote cell growth in the retina. Likewise, the odorant receptor for sandalwood can accelerate hair growth and wound healing, whereas it can inhibit the proliferation of leukemia cells.

Fragrances that activate these receptors are not only those that enter the body through the skin, food or breathing, but also those that are produced by microbes in the intestines, bronchi or on the skin.

This finding, combined with the fact that only 50 of the 350 odorant receptors found in humans are currently known, opens the door to entirely new therapeutic approaches for the future. Professor Hanns Hatt of Ruhr University Bochum explains:

"The further decoding of olfactory receptors, which are present in large quantities in human tissues, as well as the decoding of their diverse effects and the associated activating substances, will open up previously unimagined possibilities for pharmaceutical treatment."

Use in cancer therapy also appears promising, as odorant receptors are often present in large quantities in cancer cells, and their receptor types can differ from those of healthy cells. Therefore, odorant receptors could be considered as tumor markers in diagnostics. Professor Hatt also sees potential in therapy, particularly for tumors such as colon or bladder cancer, which are easily accessible to external odorants.

(Source: Lee, Sung Joon; Depoortere, Inge; Hatt, Hanns. Nature Reviews Drug Discovery 18, 116-138 (2019))

Current studies on the individual essential oils

Bergamot

The essential oil extracted from bergamot is used worldwide in aromatherapy to To relieve pain, facilitate sleep induction and/or minimize the effects of stress-related anxietyPreclinical pharmacological data show that bergamot essential oil (BEO) modulates specific neurotransmissions and exhibits a relaxing, anxiolytic effect. Several studies on essential oils indicate a role for serotonergic (5-HT) neurotransmission in anxiety. Source: https://pubmed.ncbi.nlm.nih.gov/32283606/

Preclinical studies have recently shown that bergamot essential oil possesses remarkable neurobiological effects. It can influence synaptic transmission and has demonstrated neuroprotective properties. Bergamot oil is also frequently used in aromatherapy to minimize the symptoms of stress-related anxiety and mild mood disorders.

The following study tested the endocrinological, physiological, and psychological effects of bergamot oil vapor inhalation on 41 healthy women in a randomized crossover study design. The volunteers were exposed to three experimental setups (rest (R), rest + steam (RW), rest + steam + bergamot essential oil (RWB)) for 15 minutes each. Immediately after each setup, saliva samples were collected, and cortisol levels were measured:

Cortisol levels in the RWB group were significantly lower compared to the R group. The results of this study demonstrate that bergamot oil, combined with steam, exerts psychological and physiological effects in a relatively short period of time.Source: https://pubmed.ncbi.nlm.nih.gov/25824404/

The following study investigated the anxiolytic/sedative effects of bergamot oil in rats. Analysis of the data suggests that BEO induces anxiolytic/relaxing effects in animal behavioral tasks: https://pubmed.ncbi.nlm.nih.gov/28398260/

Bergamot essential oil is also increasingly being used in dementia therapy. Cognitive impairment is a serious, but not the only, problem in dementia: Behavioral and psychological syndromes known as neuropsychiatric symptoms of dementia significantly reduce quality of life. This cluster of symptoms includes anxiety, depression, wandering, delusions, hallucinations, misidentifications, agitation, and aggression.

Aromatherapy provides positive results in controlling restlessness, one of the central symptoms. Dementia patients are often unable to verbalize pain, which leads to unrelieved symptoms and contributes to restlessness. Bergamot essential oil provides extensive preclinical evidence for analgesic (d.h. pain-relieving) properties. Bergamot essential oil induces the anxiolytic effect typical of benzodiazepines without sedation. Source: https://pubmed.ncbi.nlm.nih.gov/31284573/

Citronella

Mosquito-borne diseases such as malaria, yellow fever, and dengue fever are the main causes of significant morbidity and mortality in livestock and humans worldwide. Several reports of adverse effects of synthetic insect repellents, such as skin rashes, hives, or brain damage in children, are available in the literature. Therefore, natural insect repellents such as essential oils have recently been explored as alternatives. One such essential oil that has been extensively studied is citronella oil. This essential oil has demonstrated good efficacy against mosquitoes. It is a blend of components including citronellal, citronellol, and geraniol as the main constituents, which, in addition to mosquito-repelling properties, contribute to various activities (antimicrobial, antioxidant, antispasmodic, and wound-healing).

https://pubmed.ncbi.nlm.nih.gov/30019646/

Eucalyptus oil

Cineole comes v.aIt is found in eucalyptus and bay leaves and is perceived by humans via the olfactory nerve. At higher concentrations, it is also perceived via the trigeminal nerve – a cranial nerve that, for example, causes the burning and hot sensation when eating chili and the cold sensation when consuming menthol, which also occurs upon contact with cineole. By activating the trigeminal nerve, also known as the "warning nerve," cineole makes you more alert and energized.

geranium

Geraniol comes v.a. in roses and geraniums. It has a calming, relaxing effect and makes us more relaxed. Biochemically, geraniol enhances the effect of the body's own messenger substance GABA, which u.a. is crucial for inducing and maintaining sleep. Pharmaceutical sedatives such as benzodiazepines or barbiturates exert their effect in the same way, by binding to the corresponding GABA receptor.

Breast cancer is associated with high morbidity and mortality. Chemotherapy and toxicity are the main factors limiting treatment success in aggressive breast cancer cases. The following study investigated the potential effects of frankincense, pine needle, and geranium essential oils on breast cancer cell viability, proliferation, migration, and invasion, as well as the possible mechanisms involved. MCF-7 breast cancer cells were treated with these essential oils, and it was demonstrated that these essential oils suppressed cell viability, proliferation, migration, and invasion in human MCF-7 breast cancer cells.

Further data showed that frankincense, pine needle, and geranium essential oils induced apoptosis but did not affect cell cycle progression. Consistent with the in vitro activities, frankincense essential oil was effective in inhibiting tumor growth and inducing tumor cell apoptosis in a human breast cancer mouse model. Furthermore, these three essential oils modulated the activity of the AMPK/mTOR signaling pathway. In summary, the present study demonstrates that frankincense, pine needle, and geranium essential oils were involved in BC cell progression, possibly via the AMPK/mTOR pathway. Source: https://pubmed.ncbi.nlm.nih.gov/29115548/

COVID-19 has been declared the most serious global health emergency in modern history. The angiotensin-converting enzyme 2 (ACE2) receptor, a host cell receptor, has been found to play a crucial role in viral cell entry. Therefore, ACE2 blockers may be a potential target for antiviral intervention. The following study investigated the ACE2 inhibitory effects of 10 essential oils. Among them, geranium and lemon oils exhibited significant ACE2 inhibitory effects in epithelial cells. Furthermore, immunoblotting and qPCR analyses also confirmed that geranium and lemon oils possess potent ACE2 inhibitory effects. These results suggest that geranium and lemon essential oils and their derived compounds are valuable natural antiviral agents that may contribute to preventing SARS-CoV-2/COVID-19 from entering the human body. Source: https://pubmed.ncbi.nlm.nih.gov/32575476/

Acinetobacter species are among the so-called "hospital germs" and are organisms that can cause purulent infections in any organ system. Their resistance to some antibiotics and their ability to produce biofilms contribute to their virulence. The aim of the following study was to determine the antibacterial properties of cinnamon, lavender, and geranium essential oils against bacteria of the genus Acinetobacter isolated from several clinical samples and from the hospital environment. The study concluded that these three essential oils are best suited to combating infections caused by bacteria of the genus Acinetobacter as components of formulations for hygiene and disinfection of the hospital environment. Source: https://pubmed.ncbi.nlm.nih.gov/25514231/

Immortelle & Lavender

Lavender and immortelle essential oils are widely used to treat a variety of human conditions. The aim of the following study was to investigate the cytotoxic/genotoxic effects of lavender and immortelle oil on plant cells (Allium cepa) and human lymphocytes, as well as their antimicrobial potential on nine bacterial and fungal strains. The results confirm that lavender and immortelle essential oils exhibited cytotoxic/genotoxic effects in both plant and human cells, as well as antimicrobial properties. Further studies are needed to substantiate these findings. Source: https://pubmed.ncbi.nlm.nih.gov/30607990/

lavender

Essential oils distilled from members of the genus Lavandula have been used both cosmetically and therapeutically for centuries. Although there is considerable anecdotal information about the biological activity of these oils, much of it has long been unsupported by scientific or clinical evidence.

Claims for lavender oil include being antibacterial, antifungal, digestive (gentle muscle relaxant), sedative, antidepressant, and effective for burns and insect bites.

However, there is now both scientific and clinical data that supports the traditional use of lavender; Source: https://pubmed.ncbi.nlm.nih.gov/12112282/

Example: https://pubmed.ncbi.nlm.nih.gov/22517298/ This study suggests that inhalation of lavender essential oil may be an effective and safe treatment for the acute management of migraine headaches.

Aromatherapy also represents a promising therapeutic alternative for alleviating depressive symptoms in depression. Lavender essential oil has been the focus of clinical studies due to its positive effects on mood. An animal model of chronic administration of high-dose corticosterone to induce depression- and anxiety-like behavior and reduced neurogenesis was used to investigate the biological changes induced by aromatherapy. 24 adult male Sprague-Dawley rats were randomly divided into four groups. Behavioral tests were conducted at the end of the 14-day treatment period. The results showed that treatment with lavender essential oil improved the depression-like behavior induced by chronic corticosterone administration. (Source: https://pubmed.ncbi.nlm.nih.gov/30825591/)

A 2019 review considered human clinical trials (n = 7), animal studies (n = 5), in vitro studies (n = 2), and previously conducted reviews (n = 6) and found a faster wound healing rate, increased collagen expression, and increased activity of proteins involved in tissue remodeling in wounds treated with lavender essential oil. Current literature thus clearly indicates a potential therapeutic benefit of lavender essential oil in wound healing. However, standardization of the chemical composition and additional high-quality human clinical trials are needed to further evaluate the safety and efficacy of lavender essential oil in clinical practice. Source: https://pubmed.ncbi.nlm.nih.gov/32589447/

Aromatherapy massage with lavender essential oil was also shown to relieve pain in patients with knee osteoarthritis. However, further studies are needed to confirm the results of this study. Source: https://pubmed.ncbi.nlm.nih.gov/27863613/

Lemongrass

The following study demonstrates promising antifungal (antimicrobial activity against fungal diseases) activity of lemongrass essential oil against Candida albicans, Candida tropicalis, and Aspergillus niger. It concludes that lemongrass essential oil has remarkable potential for developing drugs to treat fungal infections and skin inflammation, which should be investigated in future studies. Source: https://pubmed.ncbi.nlm.nih.gov/25242268/

Lemongrass essential oil is also used to repel mosquitoes. The following study examined the spatial repellency of essential oils against the tropical yellow fever mosquito (Aedes aegypti) and local mosquito populations in coastal British Columbia (Canada). In laboratory experiments following World Health Organization protocols, three of the tested essential oils proved to be effective against the yellow fever mosquito: cinnamon bark, lemongrass, and rosemary. Source: https://pubmed.ncbi.nlm.nih.gov/31143941/

mandarin

The effects of mandarin peel essential oil were investigated on the growth of two human tumor cell lines (lung adenocarcinoma A549 and hepatocarcinoma HepG2). The essential oil was obtained by cold pressing. Mandarin essential oil demonstrated a strong, dose-dependent effect on the growth inhibition of these tumor cell lines.The essential oil was more effective in A549 than in HepG2 cells. It is likely that minor components could have additive or synergistic effects. Therefore, mandarin essential oil could lead to the development of antitumor agents or complementary and alternative medicines for the treatment of various cancers. Source: https://pubmed.ncbi.nlm.nih.gov/22943501/

Orange

In the following study, the orange peel of 12 varieties of Citrus sinensis from central-eastern Sicily was used to obtain essential oils and extracts. Some were extracted by steam distillation, others by hexane extraction. 54 components were identified in the steam essential oils and 44 in the extracts. In all varieties, the main component is d-limonene (73.9-97%). Antimicrobial activity was tested against three microorganisms (Staphylococcus aureus, Listeria monocytogens, and Pseudomonas aeruginosa) and confirmed for all varieties of orange essential oil. The 'Sanguinello' and 'Solarino Moro' essential oils are significantly active against L. monocytogenes, while the 'Valencia' hexane extract is active against all tested microorganisms. Source: https://pubmed.ncbi.nlm.nih.gov/27535797/

The following study aimed to compare the effects of aromatherapy with lavender and orange essential oils on fatigue in dialysis patients. Ninety subjects were randomly divided into three groups: aromatherapy with lavender essential oil, aromatherapy with orange essential oil, and control. In each experimental group, subjects inhaled five drops of lavender essential oil and five drops of orange essential oil. Results: The difference in mean fatigue scores before and after the intervention was statistically significant in each of the experimental groups, but this difference was not significant in the control group. D.h.: Aromatherapy with lavender essential oil and orange essential oil can reduce fatigue in hemodialysis patients. Source: https://pubmed.ncbi.nlm.nih.gov/31383445/

The following study showed that orange peel essential oil had a good dose-dependent inhibitory effect on the proliferation of HepG2 liver tumor cells and HCT116 colorectal cancer cells. When the essential oil concentration was 0.6 μl/ml or higher, the viability rate of both cancer cells became lower than 13%. The Transwell assay showed that the essential oil could inhibit the migration of both cancer cells at a concentration of 0.3 μl/ml. Source: https://pubmed.ncbi.nlm.nih.gov/30704118/

In the following study, an essential oil was produced by cold-pressing orange peels followed by molecular distillation. The anticancer activities of this orange essential oil, as well as some of its main components, were investigated using MTT tests: This orange peel essential oil showed a positive effect on inhibiting the proliferation of a human lung cancer cell line A549 and a prostate cancer cell line 22RV-1. Some of the oil components exhibited high anticancer potential and merit further investigation. Source: https://pubmed.ncbi.nlm.nih.gov/28829378/

peppermint

https://pubmed.ncbi.nlm.nih.gov/18041606/

This study provides further evidence of the influence of essential plant oil aromas on aspects of cognition and mood in healthy participants. One hundred and forty-four volunteers were randomly assigned to the ylang-ylang aroma, peppermint aroma, or no aroma control conditions.

Peppermint was found to improve memory, while ylang-ylang impaired it and increased processing speed. Regarding subjective mood, peppermint increased alertness, while ylang-ylang decreased it, but significantly increased calmness.These results support the claim that essential oil aromas can have significant and idiosyncratic effects on both subjective and objective evaluations of aspects of human behavior.

In the following study, essential oils of spearmint and peppermint (Mentha spicata/piperita) were pre-tested for neurotransmitter receptor binding and acetylcholinesterase (AChE) inhibition. In a double-blind, placebo-controlled, balanced crossover study, 24 participants (mean age 25.2 years) consumed single doses of an encapsulated placebo and 50 µl or 100 µl of the most promising essential oil (peppermint with nicotine/GABAA receptor binding). Psychological functioning was assessed using mood scales and a battery of standardized, cognitively demanding tasks pre-dose and 1, 3, and 6 hours post-dose. Results: The highest dose (100 µl) of the essential oil improved performance on the cognitively demanding Rapid Visual Information Processing (RVIP) task 1 h and 3 h after dosing, and both doses attenuated fatigue and improved performance on the Serial 3-second Subtraction task 3 h after dosing. Conclusion: Peppermint (Mentha piperita) essential oil with high menthol/menthone content improves performance on demanding cognitive tasks and attenuates the increase in mental fatigue associated with prolonged cognitive task performance in healthy adults. Future research should consider investigating even higher doses. Source: https://pubmed.ncbi.nlm.nih.gov/30087294/

rosemary

Rosemary essential oil is already used as a preservative in the food industry due to its antioxidant and antimicrobial activities; however, it has been shown to possess additional health benefits. The aim of the following study was to evaluate the protective effect of rosemary essential oil on carbon tetrachloride-induced liver injury in rats and to investigate whether its mechanism of action is associated with a modulation of hepatic oxidative status. Rosemary essential oil at doses of 5 mg/kg and 10 mg/kg was found to exert liver-protective effects by reducing serum AST and ALT activities by 2-fold in rats with carbon tetrachloride-induced acute liver injury. Rosemary essential oil prevented the carbon tetrachloride-induced increase in lipid peroxidation. Furthermore, pretreatment with the studied essential oil for 7 days significantly reversed the activities of the antioxidant enzymes catalase, peroxidase, glutathione peroxidase, and glutathione reductase in liver homogenates, especially at a dose of 10 mg/kg. D.hThese results demonstrate that, in addition to its antioxidant capacity, rosemary essential oil also exerts its liver-protective effects by activating physiological defense mechanisms. Source: https://pubmed.ncbi.nlm.nih.gov/25002023/

sage

https://pubmed.ncbi.nlm.nih.gov/32688401/

Sage is a biennial plant typical of the Mediterranean and v.a. is cultivated for its essential oil, which is widely used in the flavor and fragrance industry, as well as in aromatherapy for its relaxing and immunomodulatory effects. In the following study, clary sage essential oil was analyzed and investigated for its effects on heart rate, blood pressure, and mood in healthy female and male volunteers. Thirty-two participants, including 16 women and 18 men, inhaled the sage oil for 30 minutes (pure water served as a control). The observed decrease in heart rate was significantly greater in women than in men (p = 0.026).

Tea tree oil

Tea tree oil is an essential oil steam distilled from the Australian native plant Melaleuca alternifolia. This essential oil has been used in Australia for almost 100 years, but is now available worldwide both as a pure oil and as an active ingredient in a variety of products. The oil is extracted from the leaves of the tea tree by steam distillation and has a sharp camphor scent followed by a menthol-like cooling sensation.

It has a minimal content of terpinen-4-ol and a maximum content of 1,8-cineole. Terpinen-4-ol is an important component of tea tree oil, exhibiting potent antimicrobial and anti-inflammatory properties. Tea tree oil exerts antioxidant activity and has been reported to have broad-spectrum antimicrobial activity against bacterial, viral, fungal, and protozoal infections affecting the skin and mucous membranes. Several studies have suggested the use of tea tree oil for the treatment of acne vulgaris, seborrheic dermatitis, and chronic gingivitis. It also accelerates the wound healing process and exhibits anti-skin cancer activity. This review opens new horizons for dermatologists in the use of this herbal active ingredient. Source: https://pubmed.ncbi.nlm.nih.gov/22998411/

The main uses of tea tree oil have historically benefited from its antiseptic and anti-inflammatory effects. The following review summarizes recent developments in the antimicrobial and anti-inflammatory activities of the oil and its components, as well as clinical efficacy: https://pubmed.ncbi.nlm.nih.gov/16418522/

For the treatment of acne see also: https://pubmed.ncbi.nlm.nih.gov/25465857/

thyme

Thymol is one of the main components of the essential oils of thyme (Thymus vulgaris L., Lamiaceae), a medicinal plant with multiple therapeutic properties. Native to the Mediterranean region, this plant is widely used as a culinary herb and also has a long history of use for various medicinal purposes. Thymol and thyme today offer diverse functional possibilities in the pharmaceutical, food, and cosmetic industries. Interest in formulating pharmaceuticals, nutraceuticals, and cosmeceuticals based on thymol has been driven by several studies investigating the potential therapeutic applications of this compound for the treatment of diseases of the respiratory, nervous, and cardiovascular systems. In addition, this compound also exhibits antimicrobial, antioxidant, anticarcinogenic, anti-inflammatory, and antispasmodic activities, as well as potential as an adaptogen (immunomodulator). These bioactivities have been discussed in the following review: https://pubmed.ncbi.nlm.nih.gov/29785774/

Thymol (2-isopropyl-5-methylphenol) is a phenolic monoterpene found primarily in thyme species. It is one of the main components of thyme essential oil. Both thymol and thyme essential oil have long been used in traditional medicine as expectorant, anti-inflammatory, antiviral, antibacterial, and antiseptic agents, primarily in the treatment of upper respiratory tract infections. Recent studies have demonstrated their antibiofilm, antifungal, antiviral, and anticancer properties. New therapeutic formulations, such as nanocapsules containing these components, may also be beneficial in medical practice and open up opportunities for their widespread use. The extensive application of thymol and thyme essential oil in healthcare is very promising but requires further research and analysis.Source: https://pubmed.ncbi.nlm.nih.gov/32917001/

The following study suggests that thyme oil and thymol act as promising antibiofilm agents against drug-resistant strains of Candida species: https://pubmed.ncbi.nlm.nih.gov/32008964/

incense

The resin of the Boswellia species has long been used as incense in religious and cultural ceremonies and in medicine. Boswellia serrata is a medium to large branched tree in the Burseraceae family (genus Boswellia) that grows in dry, mountainous regions of India, North Africa, and the Middle East. Oleo-gum resin is extracted from the incision on the tree trunk and then stored in a specially made bamboo basket to remove the oil content and solidify the resin. After processing, the gum resin is sorted according to flavor, color, shape, and size. In India, the states of Andhra Pradesh, Gujarat, Madhya Pradesh, Jharkhand, and Chhattisgarh are the main sources of Boswellia serrata. The oleo-gum resins contain 30–60% resin, 5–10% essential oils soluble in organic solvents, and the remainder consists of polysaccharides. Gum resin extracts of Boswellia serrata have been traditionally used in folk medicine for centuries to treat various chronic inflammatory diseases. The resinous part of Boswellia serrata contains monoterpenes, diterpenes, triterpenes, tetracyclic triterpenic acids, and four major pentacyclic triterpenic acids: β-boswellic acid, acetyl-β-boswellic acid, 11-keto-β-boswellic acid, and acetyl-11-keto-β-boswellic acid, which are responsible for inhibiting pro-inflammatory enzymes. Of these four boswellic acids, acetyl-11-keto-β-boswellic acid is the most potent inhibitor of 5-lipoxygenase, an enzyme responsible for inflammation. Source: https://pubmed.ncbi.nlm.nih.gov/22457547/

Gum resins, extracted from trees of the Burseraceae family (Boswellia sp.), are important components of frankincense. Gum resins have been shown to possess anti-inflammatory and antineoplastic effects. Essential oil produced by distillation of gum resin traditionally used for aromatherapy has also been shown to exhibit tumor cell-specific antiproliferative and proapoptotic activities. The aim of the following study was to optimize the conditions for the production of Boswellea sacra essential oil with the highest biological activity in inducing tumor cell-specific cytotoxicity and suppressing aggressive tumor phenotypes in human breast cancer cells.

Results: High-molecular-weight compounds, including boswellic acids, were more abundant in Boswellia sacra essential oil produced by hydrodistillation at 100°C. All three human breast cancer cell lines were sensitive to essential oil treatment, exhibiting reduced cell viability and increased cell death, while the immortalized normal human breast cell line was more resistant to essential oil treatment. Boswellia sacra essential oil hydrodistilled at 100°C was more effective than the essential oil produced at 78°C in inducing cancer cell death (T47D cells).

Similar to our previous observations in human bladder cancer cells, Boswellia sacra essential oil induces breast cancer cell-specific cytotoxicity. The suppression of cellular network formation and disruption of spheroid development of breast cancer cells by Boswellia sacra essential oil suggest that the essential oil may be effective in advanced breast cancer.Future preclinical and clinical studies are urgently needed to evaluate the safety and efficacy of Boswellia sacra essential oil as a therapeutic agent for the treatment of breast cancer. Source: https://pubmed.ncbi.nlm.nih.gov/22171782/

Gum resins from Boswellia species, also known as frankincense, are used as a primary ingredient in Ayurvedic and Chinese medicine to treat a variety of health problems. Both chemical frankincense extracts and essential oils prepared from gum resins of Boswellia species exhibit antineoplastic activity and have been investigated as potential anticancer agents. The objectives of the following study are to identify optimal conditions for the production of frankincense essential oil, which possesses potent antitumor activity, and to evaluate its activity in both cultured human pancreatic cancer cells and a mouse cancer model.

Results: Longer duration and higher hydrodistillation temperatures resulted in higher abundance of high-molecular-weight compounds, including boswellic acids, in frankincense essential oil fractions. Human pancreatic cancer cells were sensitive to treatment with fractions III and IV (which contain higher molecular weight compounds), exhibiting suppressed cell viability and increased cell death. All fractions of Boswellia sacra frankincense essential oil are capable of suppressing the viability of a range of human pancreatic cancer cell lines and inducing apoptosis. The effectiveness of essential oil suppression on tumor cell viability may be related to the greater abundance of high-molecular-weight compounds in fractions III and IV. Although the chemical components responsible for tumor cell cytotoxicity remain undefined, essential oil produced by hydrodistillation of Boswellia sacra gum resins may be a useful alternative therapeutic agent for treating patients with pancreatic adenocarcinoma, an aggressive cancer with a poor prognosis. Source: https://pubmed.ncbi.nlm.nih.gov/23237355/

The aim of the following study was to investigate frankincense essential oil for its anti-tumor activity and signaling pathways in bladder cancer cells.Result: Frankincense oil suppressed cell viability in J82 cells of transitional carcinoma of the bladder, but not in healthy (UROtsa) cells. A comprehensive gene expression analysis confirmed that frankincense oil activates genes responsible for cell cycle arrest, suppression of cell growth, and apoptosis in J82 cells. D.hFrankincense oil appears to distinguish cancer cells from normal bladder cells and suppress the viability of cancer cells. Frankincense oil could therefore be an alternative intra-bladder treatment. Means for the treatment of bladder cancer. Source: https://pubmed.ncbi.nlm.nih.gov/19296830/

The following study investigated the effects of frankincense essential oil and its main constituents, limonene and α-pinene, on sleep and stress. The effects on plasma levels of corticosterone and glutathione (GSH), as well as on sleep and wakefulness, were investigated in sleep-deprived rats. The frankincense essential oil was applied to the skin after dilution in jojoba oil as a vehicle. d.hApplied topically. Frankincense essential oil, at a dilution of 1/1000, significantly reduced corticosterone levels (p < 0.05) and led to a significant reduction in plasma glutathione levels. Concentrations of oxidative metabolite products were reduced by frankincense. In sleep-deprived rats, frankincense oil enhanced non-rapid eye movement sleep. This study suggests that frankincense essential oil improves sleep and reduces stress. Source: https://pubmed.ncbi.nlm.nih.gov/31582666/

Ylang-Ylang

Ylang-ylang (Cananga odorata) has traditionally been used to treat malaria, stomach problems, asthma, gout, and rheumatism. Numerous phytochemical studies have now identified the constituents contained in ylang-ylang essential oils, including monoterpenes, sesquiterpenes, and phenylpropanoids. Source: https://pubmed.ncbi.nlm.nih.gov/26294929/

Another study (https://pubmed.ncbi.nlm.nih.gov/18041606/) provides further evidence of the influence of essential plant oil aromas on aspects of cognition and mood in healthy participants: One hundred and forty-four volunteers were randomly assigned to the ylang-ylang aroma, peppermint aroma, or no aroma control conditions. Cognitive performance was assessed using the Cognitive Drug Research computerized assessment battery, with mood scales completed before and after the cognitive test. Peppermint was found to improve memory. Regarding subjective mood, peppermint increased alertness and ylang-ylang decreased it, but significantly increased calmness. These results support the claim that essential oil aromas can have significant and idiosyncratic effects on both the subjective and objective assessment of aspects of human behavior.

The following study investigated the biochemical mechanism of the calming effect of Ylang Ylang essential oil in mice: https://pubmed.ncbi.nlm.nih.gov/29545208/ - with the result that ylang ylang essential oil reduced ERK1/2 phosphorylation in both the PFC and the hippocampus. Downregulation of phospho-CREB (p < 0.05) and c-Fos (p < 0.05) was observed only in the hippocampus. The essential oil also influenced serotonin metabolism in the brain and reduced corticosterone levels in the blood plasma of m-CPP-treated mice.

cedar

Candida albicans can form biofilms composed of yeast, hyphal and pseudohyphal elements.The following study describes the chemical composition, antibiofilm, and antihyphal activities of cedar essential oil, which exhibits remarkable antibiofilm activity against Candida albicans but does not affect planktonic cell growth. Nineteen components were identified in cedar essential oil, of which phenols were the main constituents. Of these, camphor, fenchone, fenchyl alcohol, α-thujone, and borneol significantly reduced Candida albicans biofilm formation. Source: https://pubmed.ncbi.nlm.nih.gov/28824600/

The anti-Helicobacter pylori properties of 26 different commercial essential oils were investigated in vitro in the following study. Nine essential oils with different anti-Helicobacter activities were selected, and phytochemical analyses of the selected essential oils were performed using GC-MS. The phenol red method was used to screen the effect of essential oils on urease activity. The most active essential oils were thyme, lemongrass, cedarwood, and lemon balm oils. Cedarwood oil was the most active. Source: https://pubmed.ncbi.nlm.nih.gov/32013183/

Swiss pine

The following study determined the chemical composition of pine needle (Cedrus deodara) essential oil and evaluated its antioxidant and antimicrobial activity. Twenty-three components, representing 95.79% of the oil, were identified. The main constituents include α-terpineol (30.2%), linalool (24.47%), limonene (17.01%), anethole (14.57%), caryophyllene (3.14%), and eugenol (2.14%). Pine needle essential oil exhibited remarkable antioxidant activity in scavenging free radicals and lipid peroxidation. Furthermore, the essential oil demonstrated potent antimicrobial activity against typical foodborne microorganisms. Source: https://pubmed.ncbi.nlm.nih.gov/22757704/

The following study investigated the anticancer activity of pine needle (Pinus roxburghii) essential oil and demonstrated cytotoxicity induction in colon, leukemia, multiple myeloma, pancreatic, head and neck, and lung cancer cells exposed to this essential oil. Essential oil-induced apoptosis was confirmed by the cleavage of PARP and caspase-3, which suppressed the colony-forming ability of tumor cells. A 50% inhibition was observed at a dose of 25 μg/ml.Furthermore, essential oil inhibited the activation of the inflammatory transcription factor NF-κB and the expression of NF-κB-regulated gene products associated with cell survival (survivin, c-FLIP, Bcl-2, Bcl-xL, c-Myc, c-IAP2), proliferation (cyclin D1), and metastasis (MMP-9). The study concludes that pine needle essential oil possesses significant anticancer activity and could be used as an anticancer agent, which requires further research to identify the bioactive compounds, followed by in vivo studies. Source: https://pubmed.ncbi.nlm.nih.gov/29743861/

The following study examines the effects of pine needle oil in the treatment of Alzheimer's disease/dementia. Alzheimer's disease is the most common neurodegenerative disease. It is characterized by the deposition of amyloid-beta peptide, which leads to memory impairment, oxidative stress, and neurodegeneration. Aromatherapy with essential oils may represent a natural treatment option for Alzheimer's disease. Therefore, this study aimed to identify the neuroprotective and beneficial effects on the central nervous system of pine needle (Pinus halepensis) essential oil in a rat model of acute amyloid-beta toxicity. The results suggest that pine needle essential oil from Pinus halepensis has beneficial effects on the central nervous system and neuroprotective effects and can be considered a therapeutic tool for attenuating Aβ toxicity and neuronal dysfunction. Source: https://pubmed.ncbi.nlm.nih.gov/30784941/

The following article investigated the anti-tumor activity of Korean pine (Pinus koraiensis) essential oil on metastatic gastric cancer cells (MGC-803 cell line) and its mechanism. In vitro anti-tumor experiments showed that the oil could significantly inhibit the proliferation and migration of MGC-803 cells, arrest the cell cycle in the G2/M phase, reduce mitochondrial membrane potential, and induce apoptosis. The results demonstrated that Korean pine essential oil can exert anti-tumor activity via the HIPPO/YAP signaling pathway. The anti-tumor mechanism of this oil should be further investigated. Source: https://pubmed.ncbi.nlm.nih.gov/31731517/