Essential Oils

Evidence Based Research on Essential Oils

Peppermint (Mentha Piperita):

A meta-analysis published in BMC Complementary Medicine and Therapies revealed that peppermint oil possesses properties that could help relieve IBS(Irritable bowel syndrome). It included a total of 12 randomized control trials that concluded that peppermint oil is a safe and effective therapy to alleviate the clinical symptoms in an adult with IBS.
A study published in The Digestive Diseases and Sciences investigated the effectiveness of peppermint oil to ease chest pain and dysphagia(difficulty to eat)due to oesophageal motility disorder. The result reported that more than 60% of the patients had improved and experienced symptomatic relief from dysphagia and chest pain.
A double blind randomized control trial, published in the International Journal of Clinical Practice, investigated the effectiveness of menthol (peppermint oil)for the treatment of migraine without aura. It found that headaches due to migraines and other clinical symptoms such as nausea, vomiting and photophobia were significantly relieved after the application of menthol in the experimental group. Besides, the study supported menthol(peppermint) safe and therapeutic for relieving migraines.
A triple-blind clinical trial published in the Iranian Journal of Pharmaceutical Research revealed that topical use of peppermint oil could help relieve Pruritis Gravidarum (itching during pregnancy). It further added that peppermint oil produces a cooling effect and act as a mild analgesic which causes no toxicity on pregnancy and breastfeeding.

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Black seed oil (Nigella sativa):

A randomized controlled trial published in Phytomedicine revealed that daily intake of 5 ml black seed oil for consecutive two months could help reducing male infertility due to unsatisfactory quality of the sperms. It further added that black seed oil enhances the quality of sperm count, motility, morphology, semen volume and PH in the experimental group.
A study published in The Iranian Journal of Reproductive Medicine investigated the effectiveness of black seed oil on the fertility of male rats. It found that higher doses of black seed oil increase fertility by enhancing LH and testosterone concentration in male rats.
A randomized control, published in Immunological Investigations , studied the effectiveness of black seed oil on T lymphocytes caused Rheumatoid Arthritis. It found 1grm black seed oil caused a significant reduction in the clinical symptoms, inflammatory marker(C reactive protein) and T cell(reduce CD4/CD8 ratio).
A randomized, double-blind control trial published in Food Research International investigated the 12 weeks intervention of black seed oil. It revealed improved glycaemic status in patients with type 2 diabetes. It further added that black seed oil decreased BMI, fasting blood sugar, Hb1ac, triglyceride and LDL-cholesterol in type 2 diabetes, as compared to the control group.
A medical study underwent a randomized, single-blind control trial to investigate the Hb1ac lowering activity of black seed oil in patients with high metabolic diseases(such as diabetes type 2)risk. It found a significant decrease in the Hb1ac levels after the administration 1.5-3Ml/day of black seed oil for 20 days. The study was optimistic about the Hb1ac lowering effect of black seed oil adjunct with the hypoglycaemic drug in patients at metabolic disease risk.
Another study published in BMC Complementary and Alternative Medicine analysed the effect of Nigella sativa (black seed oil) in lowering blood glucose in induced diabetes Miletus rats. It found that black seed oil reduced hyperglycaemia and provoked antioxidant activity to remove free radicals to decrease the risk of diabetic complications.

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Spearmint (Mentha Spicata):

A study published in the Journal of Pathogens revealed that spearmint oil possessed potent bactericidal properties against foodborne bacteria. It further added that spearmint oil provoked intense antibacterial effects against gram-positive bacteria, where the inhibition of Listeria monocytogenes was remarkable.
An animal-based study, published in Endocrine, Metabolic &Immune Disorders Drug Targets, investigated the effect of spearmint on the glucose levels of induced diabetic rats. It found that the experimental group had improved oral glucose tolerance tests. Also, the glucose levels were comparable to the glibenclamide treatment (antidiabetic drug).
An animal-based study published in Evidence-Based Complementary and Alternative Medicine found that oral administration of spearmint extract exhibited anti-anxiety activity. It further added that spearmint extracts(1000mg/kg) could boost sleep and its duration.
Spearmint oil could help reducing blood pressure in hypertensive patients. An animal-based study, published in Fetotherapia, investigated the effect of spearmint oil as a vasodilator. The study investigated the effect of (-)-carvone (a constituent of spearmint oil)in comparison with calcium channel blocker(verapamil).It found that carvone acted as a potent vasodilator, similar to calcium channel blocker.

Clove oil (Eugenol):

Clove oil could help treat anal fissures. A human-based study conducted a single-blind randomized controlled trial to examine the effectiveness of clove oil (in cream)to treat anal fissure. A study published in the journal of Colorectal Diseases revealed that clove oil healed anal fissures in nearly 60% of patients and reduced resting anal pressures in the experimental group. It further added that the anal fissure healing produced by clove oil showed no reoccurrence of the condition within three months follow up duration.
Another study published in the Journal of Clinical & Diagnostic Research examined several naturally available ten essential oils, including clove oil, that could fight against dental caries caused by bacteria. Interestingly, the result found the highest antibacterial efficacy by clove oil. The study concluded that mouthwashes and toothpaste consisted of clove oil are reliable to protect from dental carries.
A study published in BMC Complementary Medicine and Therapies found that clove oil possesses the potent antibacterial activity against microorganisms (S. pneumonae, S. pyogenes) causing respiratory diseases.
Clove oil was proved to have an immunostimulatory effect in animal-based studies.A study published in The Journal of Pharmacy and Pharmacology analysed the immunomodulatory effect of clove oil. It found that clove oil oral administration to the immunocompetent mice increased their WBC count. Also, it boosted its delayed-type hypersensitivity response. Delayed type hypersensitivity reaction is the immune response that develops 24- 72 hours after exposure to the antigen that the immune system perceives as foreign.
An animal-based study examined the immunostimulatory activity of eugenol(clove oil)against visceral Leishmaniasis disease. Leishmaniasis is hard to treat and have fewer available treatment. The study did not only find the antileishmanial activity of clove oil, but it also enhanced cellular immunity with no adverse effects.
A study published in the Journal of Oleo Science analysed the glucose-lowering effects of clove oil. It found that clove oil inhibited lipid peroxidation in the pancreas (rat). It also produced antioxidant activities, resulting in the prevention and management of oxidate stress-induced type 2 diabetes.
An animal-based study claimed that clove oil possessed strong antithrombotic and antiplatelet aggregating properties. It further added that these antithrombotic effects were found nearly 70% protecting against shock due to pulmonary platelet thrombosis.

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Coconut (Cocos Nucifera):

A study published in Ghana Medical Journal speculated about the nutritional benefits of coconut oil. It revealed that coconut oil protected against heart diseases, infections and diabetes.
A study published in Evidence-Based Complementary and Alternative Medicine found that coconut oil inhibited viral infections by many lipid-coated viruses, such as CMV(cytomegalovirus), Epstein Barr virus(EBV), Influenza, leukaemia virus, Pneumo virus and hepatitis C virus. It exerted the effect by damaging the stability of the virus membrane and disturbing the virus assembly and maturation.
A study in the Asian Pacific Journal of Tropical Medicine found that Coconut oil also possessed antibacterial activity against P. aeruginosa, E. coli, Proteus Vulgaris and Bacillus because of monolaurin (found in coconut oil).
A study published in BMC Proceeding evaluated the effect of coconut oil on reducing blood pressures in spontaneously hypertensive rats. It found that administration of coconut oil(2ml/day) for 30 days reduced the blood pressures and oxidative stress in hypertensive rats.

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Neem (Azadirachta indica):

Neem oil is the extract from the seed kernels of the neem tree (Azadirachta indica), which contains nearly 50% of various limonoids (Referenc7,8). The constituents present in the neem oil are known to help to fight against various cancers.

An animal-based study published in The Journal of photochemistry and Photobiology B: Biology showed anti-ageing effects that were produced due to procollagen and elastin provoking properties of neem oil.
A study investigated the hypoglycaemic effects of name in diabetic rats. It found a significant reduction in blood glucose levels, comparable to glipalamide (antidiabetic drug). The study suggested that the neem extracts could also help to prevent and delaying the onset of type 2 diabetes.

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Oregano(Origanum vulgare):

The botanical name of Oregano is Origanum vulgare. Carvacrol and thymol are two vital constituents of oregano that are involved in provoking antiviral properties. A study published in Planta Medica found that both carvacrol and thymol ( present in oregano oil)possess potent antiviral characteristics when applied topically for herpes simplex viral infection treatment.
A study published in Microbial Ecology in Health and Disease found that Oregano essential oil possessed antibacterial activity(second to Thyme) against microorganisms such as Klebsiella pneumonia and Klebsiella oxytoca.
A study published in Frontiers in Microbiology investigated the effects of oregano oil on multidrug-resistant microorganisms. It found the bactericidal activity of oregano against Acinetobacter, Pseudomonas aeruginosa and MRSA (Methicillin drug-resistant staphylococcus aureus) bacteria, which was isolated from the combat casualties invitro. It exerted its bactericidal activity by damaging the bacterial cells and altering the morphology of their biofilms.
A test-tube study published in BMC Complementary Medicine and Therapies found that the thymol(a constituent of oregano oil)retained fungicidal effect against candida species which could cause oral thrush, athlete's foot and yeast infections.
A study published in the journal Planta Medica evaluated the blood pressure lowering effects of Carvacrol(oregano). It found that at 100 microg/kg, I.P., carvacrol reduced heart rate, mean arterial pressure, systolic and diastolic pressure in the anaesthetized rats. It further added that the hypotensive effect was assumed due to its cardiac L type calcium channel blocking action.

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Cinnamon oil(cinnamon verum)(cinnamon for oil derived from two trees: Cinnamomum zeylanicum & Cinnamomum vervun)

Cinnamon oil is known for its powerful effect against several multidrug-resistant microorganisms. A study published in BMC Complement and Alternative Medicine found that cinnamon bark oil possessed effective bactericidal activity against multi drug resistant P.aeruginosa that causes respiratory, urinary, skin, joint and stomach infections.
A comparative study was published in The Journal of Contemporary Dental Practice to find which essential oil can be more bactericidal against bacterial and yeast infections in the oral cavity. It revealed that cinnamon oil possessed the highest antimicrobial activity against Streptococcus mutans among the other eight essential oils.
A test-tube study published in The Journal of Clinical & Diagnostic Research investigated the antimicrobial activity of cinnamon on candida (yeast)in the bloodstream. The result showed remarkable activity on candida which was already resistant to fluconazole (an antifungal drug).
An animal-based study, published in Acta Veterinaria Brno, investigated the cholesterol-lowering effect of cinnamon oil on broiler chickens. The study claimed that cinnamon oil reduced cholesterol and provoked antioxidant effects in the experimental group.
A study published in Food and Chemical Toxicology investigated the effect of cinnamaldehyde (constituent in cinnamon oil) in reducing blood pressure associated with diabetes. The study claimed that cinnamaldehyde decreased hyperglycemia and associated high BP by normalizing the vascular contractibility with its insulinotropic effect in insulin deficiency.

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Frankincense (Olibanum oil)

Boswellia carterri, Boswellia serrata and Boswellia frereana are the botanical names for the Frankincense species. But Boswellia serrata is a commonly used species in medication.

A pilot study underwent a randomized, double-blind control trial to investigate the efficacy of the Boswellia extract (Frankincense) on patients with knee osteoarthritis, revealed a significant reduction in pain and stiffness in the patients taken the Boswellia extract. It further showed radiological improvement in the knee joint gap and less formation of the osteophyte spurs. Besides, the C- reative protein (an inflammatory marker in osteoarthritis) was also reduced in the experimental group.
A study published in the European Review for Medical and Pharmacological Sciences examined the efficacy of Boswellia serrata to treat mild Ulcerative colitis(UC) in the remission phase. It found that Boswellia (frankincense oil) was effective in relieving symptoms of mild UC, and it reduced the use of medicines and medical consultations during that time.

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Sweet Orange (Citrus sinensis):

A study published in BMC Complementary Medicine and Therapies analysed the effectiveness of applying topical sweet orange oil to control skin and soft tissue infections from staphylococcal in a dressing model. It found that the oil application on the skin cells infected with MRSA (Methicillin-resistant S. aureus) caused the bacterial death rapidly without causing damage to the liver(hepatotoxicity).

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Geranium oil (Pelargonium):

A study published in the Journal of Functional Foods analysed the effectiveness of geranium oil against neuroinflammation, a cause of neurodegenerative diseases. Nitric oxide(NO) and cyclooxygenase-2(COX-2) are the two common mediators of neuroinflammation, resulting in neuronal cell death. The study found that geranium oil could effectively inhibit these two mediators of neuroinflammation.
An animal-based study published in Phytotherapy Research investigated the effect of geranium essential oil on anxiety and depression. The results of the study showed significant anxiolytic and antidepressant activity of geranium oil among experimental rats.
An animal-based study published in the Journal of Lipids in Health and disease analysed the effect of an oral dose of geranium oil on the induced diabetic rats. The study revealed that it caused lower serum glucose levels at 150mg/kg b.w dosage, and this glycaemic lowering effect was more effective than glibenclamide (anti diabetic medication). The study believed geranium oil would help lower diabetic-associated complications and be a safe antidiabetic drug alternative for diabetic patients.
A study published in the Journal of Evidence-Based Complementary and Alternative Medicine found that geranium oil possessed powerful bactericidal, antiseptic, and antimicrobial activities. Hence, its topical application could help treat various skin problems such as acne, skin allergy and irritation.