The Full Wiki

Tea tree oil: Wikis

Advertisements
  
  

Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.

Encyclopedia

From Wikipedia, the free encyclopedia

Tea Tree Oil (Melaleuca Oil)

Tea tree oil or melaleuca oil is a clear to very pale golden hydrophobic essential oil with a fresh camphoraceous odor. 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, antibacterial action), and is also believed to have beneficial cosmetic properties. Tea tree oil is usually used diluted, as reactions are common with pure tea tree oil, but it can also cause irritation for some people when diluted.

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.

Tea tree oil has strong activity against Staphylococcus aureus including MRSA.[1] When used at 5% concentration it has not been shown to cause drug resistance; however, some resistance occurs at lower concentrations of usage such as 0.5% strength.[2]

Contents

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.[3][4]

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.[5]

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.

Tea tree plantation, Coraki.

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.[6]

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

Although tea tree oil normally is 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 (2004) ("Oil of Melaleuca, Terpinen-4-ol type"), which specifies levels of 15 components which are needed to define the oil as "tea tree oil."

Composition

Tea tree oil ISO 4730 (2004) Concentration [%]
terpinen-4-ol 30-48
γ-terpinene 10–28
α-terpinene 5–13
1,8-Cineole 0–15
α-terpinolene 1.5–5
α-terpineol 1.5–8
α-pinene 1–6
p-cymene 0.5–8

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 has activity against staphylococcus aureus including MRSA, and when used at 10% concentration is comparable with Mupirocin for application to the skin but has never been shown to cause resistance. However, this can occur at lower percentages. It is less successful for application in the nose.[7]

Tea tree oil is a known antifungal agent, effective in vitro against multiple dermatophytes found on the skin.[8] 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.[9]

Effectiveness of topical tea tree oil preparations for Candidiasis is supported by its ability to kill Candida in vitro.[10]

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.[11] In another study in 2007 5% strength gel was compared against a placebo, with statistically significant results.[12]

There is some very limited research that has shown that tea tree oil may have topical anti-viral activity, especially with the Herpes virus (cold sores, chicken pox and shingles blisters, etc.)[13]

There is clinical evidence that topical dermatological preparations containing tea tree oil may be more effective than conventional antibiotics in preventing transmittal of CA-MRSA. [14]

One study has shown a 5% tea tree oil solution to be more effective than commercial medications against the scabies mite in an in vitro situation.[15]

Diluted solutions of tea tree oil are often used as a remedy to treat bacterial and fungal infection in aquarium fish. Common brand names are Melafix and Bettafix. Melafix is a stronger dilution and Bettafix is a lighter dilution that makes it harder to overdose smaller (especially Betta) fish. It is most commonly used to promote fin and tissue regrowth but is also effective in treating other conditions such as fin rot or velvet. The remedy is used mostly on Betta fish but can also be used with other aquarium fish.

Safety

According to the American Cancer Society: "Tea tree oil is toxic when swallowed. It has been reported to cause drowsiness, confusion, hallucinations, coma, unsteadiness, weakness, vomiting, diarrhea, stomach upset, blood cell abnormalities, and severe rashes. It should be kept away from pets and children."[16]

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.[17] Allergic reactions may be due to the various oxidation products that are formed by exposure of the oil to light and/or air.[18][19]

External application of tea tree oil undiluted and/or at inappropriate high doses has been associated with toxicity, including death, in cats and other animals due to ingestion during grooming.[20][21][22]

A highly disputed case study reported in The New England Journal of Medicine concluded that repeated topical exposure of lavender and tea tree oils may have caused prepubertal gynecomastia in three young boys.[23] 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. Researchers have 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.[23] Others have cast doubt on the conclusions of the article and dismissed the study as having used "poor methodology". The research has been most criticized for making medically related conclusions about tea tree oil based on a single individual, while outside factors were more likely to have caused the condition. Critics of the study note that millions of people use products containing tea tree oil on a regular basis and there has never been another documented relation of tea tree oil and gynecomastia before or after this study was published.[24][25][26][27][28]

If used in concentrations below 4% or particularly below 1%, tea tree oil may fail to kill bacteria and create selection pressure, which may result in them becoming less sensitive to tea tree oil and even some antibiotics in vitro.[2]

Tea tree oil may cause hearing loss when used in the ears.[29]

External links

References

  1. ^ Journal of Hospital Infection (2004; 56:283–286), cited in Beauchamp, Kimberly. 2004. "Tea Tree Oil and Staph". Bastyr Center for Natural Health.
  2. ^ a b Habituation to sub-lethal concentrations of tea tree oil (Melaleuca alternifolia) is associated with reduced susceptibility to antibiotics in human pathogens
  3. ^ Shemesh, A., and W. L. Mayo. 1991. "Australian tea tree oil: a natural antiseptic and fungicidal agent." Aust. J. Pharm. 72:802-803
  4. ^ Low, T. 1990. Bush medicine. Harper Collins Publishers, North Ryde, NSW, Australia
  5. ^ Penfold, A. R., and R. Grant. 1925. "The germicidal values of some Australian essential oils and their pure constituents, together with those for some essential oil isolates, and synthetics. Part III." J. R. Soc. New South Wales 59:346-349.
  6. ^ Johns, M. R., J. E. Johns, and V. Rudolph. 1992. "Steam distillation of tea tree (Melaleuca alternifolia) oil." J. Sci. Food Agric. 58:49-53
  7. ^ [1]
  8. ^ Nenoff P, Haustein UF, Brandt W (1996). "Antifungal activity of the essential oil of Melaleuca alternifolia (tea tree oil) against pathogenic fungi in vitro". Skin Pharmacol. 9 (6): 388–94. PMID 9055360. 
  9. ^ Satchell AC, Saurajen A, Bell C, Barnetson RS (2002). "Treatment of dandruff with 5% tea tree oil shampoo". J Am Acad Dermatol. 47 (6): 852–5. doi:10.1067/mjd.2002.122734. PMID 12451368. 
  10. ^ Hammer K, Carson C, Riley T (1998). "In-vitro activity of essential oils, in particular Melaleuca alternifolia (tea tree) oil and tea tree oil products, against Candida spp". J Antimicrob Chemother 42 (5): 591–5. doi:10.1093/jac/42.5.591. PMID 9848442. 
  11. ^ Bassett I, Pannowitz D, Barnetson R (1990). "A comparative study of tea-tree oil versus benzoylperoxide in the treatment of acne". Med J Aust 153 (8): 455–8. PMID 2145499. 
  12. ^ "The efficacy of 5% topical tea tree oil gel in mild to moderate acne vulgaris: a randomized, double-blind placebo-controlled study". Level1diet.com. http://www.level1diet.com/research/id/852871. Retrieved 2008-11-28. 
  13. ^ Bishop, C.D. (1995). "Anti-viral Activity of the Essential Oil of Melaleuca alternifolia". Journal of Essential Oil Research: 641–644. 
  14. ^ David T. Bearden, George P. Allen, and J. Mark Christensen, "Comparative in vitro activities of topical wound care products against community-associated methicillin-resistant Staphylococcus aureus," The Journal of Antimicrobial Chemotherapy, June 30, 2008, Vol. 62, Number 4, pp. 769-772. [2]
  15. ^ Walton, S. et al. (2004). "Acaricidal Activity of Melaleuca alternifolia (Tea Tree) Oil". Arch Dermatol 140: 563. doi:10.1001/archderm.140.5.563. 
  16. ^ [3]
  17. ^ Lisi P, Melingi L, Pigatto P, Ayala F, Suppa F, Foti C, Angelini G (2000). "Prevalenza della sensibilizzazione all´olio essenziale di Melaleuca". Ann Ital Dermatol Allergol 54: 141–144. 
  18. ^ Hammer KA, Carson CF, Riley TV, Nielsen JB (May 2006). "A review of the toxicity of Melaleuca alternifolia (tea tree) oil". Food Chemistry Toxicology 44: 616–625. doi:10.1016/j.fct.2005.09.001. 
  19. ^ Rutherford T, Nixon R, Tam M, Tate B (May 2007). "Allergy to tea tree oil: retrospective review of 41 cases with positive patch tests over 4.5 years". Australasian Journal of Dermatology 48: 83–87. doi:10.1111/j.1440-0960.2007.00341.x. 
  20. ^ Bischoff, K. and Guale, F. (1998). "Australian Tea Tree (Melaleuca alternifolia) Oil Poisoning in Three Purebred Cats". Journal of Veterinary Diagnostic Investigation 10: 208. 
  21. ^ Villar D, Knight MJ, Hansen SR, Buck WB (April 1998). "Toxicity of melaleuca oil and related essential oils applied topically on dogs and cats". Veterinary Human Toxicology. 
  22. ^ Small, B.E.J. (1981). "Tea Tree Oil". Australian Journal of Experimental Agriculture and Animal Husbandry 21: 439. doi:10.1071/EA9810439. 
  23. ^ a b Henley D, Lipson N, Korach K, Bloch C (2007). "Prepubertal gynecomastia linked to lavender and tea tree oils". N Engl J Med 356 (5): 479–85. PMID 17267908. 
  24. ^ Cosmetics and Toiletries Magazine
  25. ^ Essential Oils Not Linked to Breast Growth in Young Boys
  26. ^ Personal Care Products Council | CTFA Statement on Essential Oils
  27. ^ http://www.fmafragrance.org/sub_pages/020107henleyresponse.pdf
  28. ^ http://www.naha.org/articles/Tisserand,%20R.%20Gynecomastia2_2007.pdf
  29. ^ eDrugDigest
Advertisements

Advertisements






Got something to say? Make a comment.
Your name
Your email address
Message