Tea tree oil

From Wikipedia, the free encyclopedia

Tea tree oil is an extraction from the Melaleuca tree. Tea tree oil should not be confused with tea oil, the sweet seasoning and cooking oil from pressed seeds of the tea plant (drinking tea) Camellia sinensis or the tea oil plant Camellia oleifera.

The term "tea tree oil" is also somewhat of a misnomer since Melaleuca alternifolia is a paperbark rather than a tea tree (genus Leptospermum). Tea tree oil or melaleuca oil is a clear to very pale golden color essential oil with a fresh camphoraceous odour. It is taken from the leaves of the Melaleuca alternifolia which is native to the northeast coast of New South Wales, Australia. The oil has beneficial medical properties (including antiseptic and antifungal action), and is also believed to have beneficial cosmetic properties.

Contents 1 History and extraction 2 Composition 3 Medicinal use 4 Safety 5 References 6 External links

[edit] History and extraction

The indigenous Bundjalung people of eastern Australia use “tea trees” as a traditional medicine by inhaling the oils from the crushed leaves to treat coughs and colds. They also sprinkle leaves on wounds, after which a poultice is applied. In addition, tea tree leaves are soaked to make an infusion to treat sore throats or skin ailments.^[1][2]

Use of the oil itself, as opposed to the unextracted plant material, did not become common practice until researcher Arthur Penfold published the first reports of its antimicrobial activity in a series of papers in the 1920s and 1930s. In evaluating the antimicrobial activity of M. alternifolia, tea tree oil was rated as 11 times more active than phenol.^[3]

The commercial tea tree oil industry was born after the medicinal properties of the oil were first reported by Penfold in the 1920s. It was produced from natural bush stands of M. alternifolia that produced oil with the appropriate chemotype. The plant material was hand cut and often distilled on the spot in makeshift, mobile, wood-fired bush stills.

Production ebbed after World War II as demand for the oil declined, presumably due to the development of effective antibiotics and the waning image of natural products. Interest in the oil was rekindled in the 1970s as part of the general renaissance of interest in natural products. Commercial plantations were established in the 1970s and 1980s, which lead to mechanization and large-scale production of a consistent essential oil product.^[4]

Among over 98 compounds contained in the oil, terpinen-4-ol is responsible for most of the antimicrobial actions.

Although tea tree oil is normally extracted from Melaleuca alternifolia commercially, it can also be extracted from Melaleuca dissitiflora and Melaleuca linariifolia. Tea tree oil is defined by international standard ISO 4730 ("Oil of Melaleuca, Terpinen-4-ol type"), which specifies levels of 14 components which are needed to define the oil as "tea tree oil."

[edit] Composition

Compound	Coldstream Plantation Tea tree oil[5] Concentration [%]	Tea tree oil Concentration [%]	Tea tree oil Concentration [%]	Tea tree oil ISO 4730 Concentration [%]
terpinen-4-ol	40.2	>30.0	39.8	>30.0
γ-terpinene	20.5	20	<15	10–28
α-terpinene	10.2	9	8.3	5–13
1,8-Cineole	3.6	—	4.5	0–15
α-terpinolene	3.6	4	3.3	1.5–5
α-terpineol	3.1	—	3.4	1.5–8
α-pinene	2.4	2.5	2.1	1–6
p-cymene	2.2	—	2.3	0.5–12

[edit] Medicinal use

Tea tree oil has been recognized as a potent antiseptic in Australia anecdotally for much longer than there has been scientific evidence. However, recent studies support a role for tea tree oil in skin care and treatment of various ailments.

Tea tree oil is a known antifungal agent, effective in vitro against multiple dermatophytes found on the skin.^[6] In vivo, shampoo with 5% tea tree oil has been shown to be an effective treatment for dandruff due to its ability to treat Malassezia furfur, the most common cause of the condition.^[7]

Tea Tree Oil is used medically as well as in cosmetic products.

Effectiveness of topical tea tree oil preparations for Candidiasis is supported by their ability to kill Candida in vitro.^[8]

In the treatment of moderate acne, topical application of 5% tea tree oil has shown an effect comparable to 5% benzoyl peroxide, albeit with slower onset of action.^[9] Another study in 2007 5% strength gel was compared against a placebo, with statistically significant results.^[10]

Tea tree oil is also effective for treating insect bites,^[11] boils and minor wounds.^[12] It has also been known to help soothe sunburn,^[13][14] poison ivy,^[15][16] ear infections,^[17] and bee stings.^[18][19]

Diluted solutions of tea tree oil are sold as remedies which claim to treat bacterial and fungal infection in pet fish.

Toothpastes and mouthwashes containing tea tree oil are shown to be effective for a number of oral problems. Some of these include halitosis (bad breath), gum disease, and canker sores.^[20][21][22]

There is some limited research that has shown that tea tree oil may have anti-viral activity, especially with the Herpes virus (cold sores, chicken pox and shingles blisters, warts, etc.)^[23]

[edit] Safety

Melaleuca oil is used almost exclusively externally.

Data on oral use of tea tree oil in humans in large quantities is sparse aside from several anecdotal reports of side effects following oral ingestion.^[24] Symptoms may include ataxia and drowsiness.

A small number of people experience allergic contact dermatitis as a reaction to dermal contact with tea tree oil. In an Italian study of 725 consecutive patients, patients were patch tested with undiluted, 1% and 0.1% Tea Tree Oil. For undiluted tea tree oil, nearly 6% of the patients observed positive reactions of skin irritation. Only 1 of 725 patients observed a positive reaction of skin irritation with the 1% dilution. None of the 725 patients observed adverse reactions with the 0.1% dilution.^[25] Allergic reactions may be due to the various oxidation products that are formed by exposure of the oil to light and/or air.^[26][27]

External application of undiluted tea tree oil and/or at inappropriate high doses has been associated with toxicity, including death, in cats and other animals.^[28][29][30]

A disputed case study reported in The New England Journal of Medicine concluded that "repeated topical exposure to lavender and tea tree oils probably caused prepubertal gynecomastia" (abnormal breast development) in three young boys.^[31] The study involved just three individuals and found lavender to be the only common ingredient used by the boys in the study. While all three cases involved the use of products containing lavender oil as an ingredient, only one boy also used products containing tea tree oil. In all cases, the prepubertal gynecomastia reversed after several months. Use of the products containing lavender and tea tree oils were also discontinued during this time. In the same paper, results from cell culture assays indicated that both essential oils exhibit weak estrogenic and antiandrogenic properties in vitro, (i.e. in a test tube, an artificial environment outside the living human organism) but no tests were conducted in vivo. Researchers also indicated that other components in these products may also have contributed to the gynecomastia, or that genetics might play a role. Researchers also noted that estrogenic or antiandrogenic activities have also been reported for some other commonly used essential oils as well as some foods such as almonds and peanuts, but cited no associated cases of prepubertal gynecomastia.^[32] Others have cast doubt on the conclusions of the article and dismissed the study as having used "poor methodology".^{[33][34][35][36][37]}

If used in concentrations below 4% or particularly below 1%, tea tree oil may fail to kill bacteria and it creates an evolutionary pressure which may result in them becoming less sensitive to tea tree oil and even some antibiotics in vitro.^[38]

Tea tree oil is not recommended for use in the ears.^[39]

[edit] References

[edit] External links

• HerbMed
• Tea Tree Oil as Acne Treatment
• Tea Tree Oil Research Group, University of Western Australia.

v • d • e Acne-treating agents (D10) Topical agents Azelaic acid • Benzoyl peroxide • Glycolic acid • Light therapy • Salicylic acid • Tea tree oil Antibiotics Clindamycin • Erythromycin • Sulfacetamide • Tetracyclines • Trimethoprim Hormonal Antiandrogens • Contraceptives Retinoids Adapalene • Isotretinoin • Tazarotene • Tretinoin

v • d • e Antifungals (D01 and J02) Antibiotics Griseofulvin • polyene antimycotics (Natamycin, Nystatin) Topical azoles imidazoles (Bifonazole, Clomidazole, Clotrimazole, Econazole, Fenticonazole, Ketoconazole, Isoconazole, Miconazole, Neticonazole, Oxiconazole, Sertaconazole, Sulconazole, Tioconazole) • triazoles (Fluconazole) • benzimidazole (Thiabendazole) Other topicals Ciclopirox • Ethylparaben • Flucytosine • Salicylic acid • Selenium sulfide • Tolnaftate • Undecylenic acid • allylamines (Amorolfine, Butenafine, Naftifine, Terbinafine) For systemic use Griseofulvin • allylamine (Terbinafine) • polyene antimycotic (Amphotericin B) • triazoles (Itraconazole, Posaconazole, Voriconazole) • echinocandins (Anidulafungin, Caspofungin, Micafungin) Other Tea tree oil • citronella oil • lemon grass • orange oil • patchouli • lemon myrtle