Tea tree oil

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Tea tree oil

Tea tree oil is an essential oil from the leaves of various trees and shrubs of the "tea tree" genera Baeckea , Kunzea , Leptospermum and Melaleuca from the myrtle family (Myrtaceae). In the 18th century, tea was made from its leaves in the Australasian region.

While the name tea tree oil in the narrower sense stands for the Australian tea tree oil from ( Melaleuca alternifolia ), it is used in the broader sense for the essential oils of various types of these genera. Oil from Melaleuca cajuputi , Melaleuca viridflora , Melaleuca leucadendra and Melaleuca quinquenervia u. a. used. Most of them contain 1,8-cineole and come from Asia and Madagascar . They are therefore not to be confused.

Australian tea tree ( Melaleuca alternifolia )

Chemical composition

Pure tea tree oil is clear to slightly yellow in color and has a fresh, aromatic smell.

Tea tree oil is a mixture of around 100 substances. The oil from Melaleuca alternifolia mainly contains (+) - terpinen-4-ol (about 40%), α-terpinene (about 20%), terpinolene , terpineol (3 to 4% each), pinene , myrcene , phellandrene , p- Cymene , limonene , 1,8-cineole.

According to the European Pharmacopoeia (PhEur), the oil from Melaleuca alternifolia is referred to as Melaleucae aetheroleum , but this is not a botanical synonym. Melaleucae alternifoliae aetheroleum or Oleum Melaleucae are further names.

Pharmacological and toxicological properties

Tea tree oil has a very strong antimicrobial effect. Compared to the relatively poisonous phenol , the tea tree oil is 11 to 13 times more effective and thus, for example, much more bactericidal and fungicidal than eucalyptus oil (phenol coefficient about 3.5). In addition to the proven antimicrobial effect of tea tree oil, other effects are claimed, such as the interception of excessive immune reactions after insect bites. When used in too low doses, tea tree oil can increase the resistance and resistance of bacteria to antibiotics. Tea tree oil is rated as a risk substance for the occurrence of contact dermatitis . Undiluted tea tree oil is therefore classified as a harmful substance.

Remedy history

It is said that the Australian Aborigines traditionally used the leaves of large-leaved tea trees for medicinal purposes. To treat colds, flu, fever and constipation, they inhaled the steam of crushed leaves boiled in water or sipped their brew. It is possible that the Aborigines traditionally also used the leaves of small-leaved tea tree species such as Melaleuca alternifolia as a wound dressing . Because of the manufacturing process, a traditional use of tea tree oil by the native people of Australia seems absurd.

A scientific distillation of tea tree oil was first achieved in 1925. Shortly afterwards, extensive fungicidal and bactericidal properties were described. Until the discovery of penicillin , tea tree oil was considered an antiseptic alternative to phenol. It practically achieved the importance of a standard antiseptic for operations , especially in the oral cavity . Oil production at that time was based on Australian wild stocks and was less than 10 tons per year. During the Second World War, tea tree oil was part of all first aid kits for Australian troops stationed in the tropics.

When penicillin and very soon other antibiotics became available after the war , it was initially forgotten. Since the 1970s, tea tree oil has enjoyed increasing popularity again as a "natural product". The increasing population interest in preparations of ethnomedicine let the oil production grow from 80 tons in 1987 to 750 tons in 1992.

Current application

Due to its antiseptic, antibacterial and fungicidal properties, tea tree oil is used in its pure form in alternative medicine , e.g. B. for the therapy of acne , neurodermatitis , psoriasis vulgaris , in wound treatment, corns , diabetic damage to health , lice, scabies , flea and tick infestations , and warts . It is also recommended for muscle pain, rheumatism , smoker's cough and varicose veins .

For (alternative) medicinal purposes, tea tree oil is extracted from the Australian tea tree ( Melaleuca alternifolia ). In addition, are sometimes essential oils of Leptospermum species, such as manuka the Leptospermum scoparium , which Kanukaöl of Kunzea ericoides and other Melaleuca species, such as the cajeput and niauli , performed under the name "tea tree oil". A pharmaceutical grade of tea tree oil is described in the European Pharmacopoeia . There are no approved finished medicinal products in Germany.

Tea tree oil is also used in cosmetic preparations: in shampoos , hand and body creams (especially for blemished skin such as acne ), in deodorants, bath additives, soaps , toothpaste , mouthwashes, shaving oils. In the case of fungal and bacterial attack on the skin (e.g. acne, athlete's foot ), preparations with 5 to 10% tea tree oil are usually used. When used in the oral cavity , tea tree oil must be diluted very heavily. The preservation of many cosmetic products is possible with tea tree oil.

External uses of tea tree oil are also known in animal care.

Evidence base

In a single-blind , randomized clinical study with 124 acne patients in 1990, a gel preparation with 5% tea tree oil was shown to be effective in reducing inflamed and non-inflamed acne lesions . Compared to a gel with 5% benzoyl peroxide , the effect was slower. There were also fewer undesirable effects. The therapeutic effectiveness for mild to moderate acne vulgaris was confirmed in 2007 in a randomized, double-blind, placebo - controlled study with 60 participants. In 2015, authors from the Cochrane Collaboration rated the quality of the evidence of effectiveness in acne as “low”.

Adverse effects and restrictions on use

safety instructions
Surname

Tea tree oil

CAS number

85085-48-9

EC number

285-377-1

ECHA InfoCard

100,077,588

GHS labeling of hazardous substances
02 - Highly / extremely flammable 07 - Warning 08 - Dangerous to health

danger

H and P phrases H: 226-302-304-315-317-411
P: 273-280-301 + 310-302 + 352-331-405-501
Toxicological data

> 1900–2600 mg kg −1 ( LD 50 ,  rat ,  oral )

The risk of developing contact allergies is viewed as critical . Triggers are different proportions of the oil ( D- limonene and α-terpinene ) and their oxidation products ascaridol and 1,2,4-trihydroxymenthan . The older the oil, the greater the risk. The oxidation process caused by light or atmospheric oxygen begins after just four days. Tea tree oil should therefore be stored protected from light and airtight at temperatures below 25 ° C. The oxidation increases the allergen content and contact eczema can occur, especially on pre-existing skin. Up to three percent of the people tested were sensitized to tea tree oil in 2003. Contact eczema very often develops when tea tree oil is applied to the skin undiluted and over a long period of time.

In 2008, the EU's Scientific Committee on Consumer Products (SCCP) recommended limiting the concentration of tea tree oil to 1% in the end product. The Federal Institute for Risk Assessment (BfR) found concentrations of up to 14.6% and increased concentrations of methyl eugenol in cosmetics , which led to complaints about these products.

Lung damage can occur if swallowed.

In 2007 Henley et al. about three prepubertal boys who showed growth of the mammary glands ( gynecomastia ) after topical application of products containing tea tree and lavender oil . The gynecomastia resolved after treatment was discontinued. In an in vitro study, Henley et al. the estrogenic and anti-androgenic activity of both oils on human cell lines . The authors concluded that it was likely repeated exposure to tea tree and lavender oil that caused prepubertal gynecomastia in the three boys.

If you want to use tea tree oil on animals, you should definitely consult a veterinarian. Tea tree oil is toxic to pets because of its terpenes and phenols. The application is often fatal for the animal. Typical symptoms of "tea tree oil poisoning" are tremors, staggering, restlessness and general weakness. Cats and dogs should not come into contact with undiluted tea tree oil because they lack the ability to break down the ingredients. Symptoms appear 2 to 12 hours after contact. In milder cases, there is salivation and vomiting. Weakness, depression, ataxia , paresis , incoordination and muscle tremors occur in half of the cases . For treatment, decontamination can be done by washing; in the case of neurological failures, medication and infusions to stabilize the circulation are indicated.

literature

  • Uwe Landvatter: Tea Tree Oil & Tea Tree Oil Formulations . Investigation of stability, liberation and permeation through human epidermis as well as antimicrobial activity taking into account the germ Helicobacter pylori. Heidelberg (Diss.) 2002.
  • Michael Harkenthal: Melaleucae aetheroleum (Australian tea tree oil). Investigation of the pharmaceutical quality, antibacterial effect in comparison to selected, traditionally used essential oils as well as irritative and allergic side effects. Heidelberg (Diss.) 2000.
  • Federal Institute for Risk Assessment: Use of undiluted tea tree oil as a cosmetic product (PDF file; 84 kB) BfR opinion of September 1, 2003
  • Robert Hegnauer : Chemotaxonomy of plants. Volume XIb-2, Springer, 2001, ISBN 3-7643-5862-9 , pp. 182-183.

Web links

Individual evidence

  1. ^ A b Ian Southwell, Robert Lowe: Tea Tree: The Genus Melaleuca. Harwood Academics, 1999, ISBN 90-5702-417-9 .
  2. ↑ U. Landvatter, R. Saller, J. Reichling: Antibacterial effect of Australian tea tree oil against various pseudomonads . In: empirical medicine . tape 50 , no. 6 , 2001, p. 340-348 , doi : 10.1055 / s-2001-15777 .
  3. ↑ Resistance in tea tree oil. In: Wissenschaft.de. February 19, 2007, accessed September 8, 2019 .
  4. ↑ a b c Federal Institute for Risk Assessment (BfR): Use of undiluted tea tree oil as a cosmetic product September 1, 2003 (PDF).
  5. ↑ a b Birger Kränke: Allergizing potency of tea tree oil. In: The dermatologist. Issue 3/1997, Volume 48, pp. 203–204. DOI: 10.1007 / s001050050572 .
  6. ↑ after Cynthia B. Olsen: The tea tree oil medicine cabinet. The holistic healer from Australia. Aitrang: Windpferd 1994 (This book neglects the allergic and health risks mentioned in the article.)
  7. ↑ BM Hausen: Tea tree oil allergy In: A. Plettenberg, WN Meigel, I. Moll (Ed.): Dermatology on the threshold of the new millennium: Current status of clinics and research. Springer-Verlag, 2000, ISBN 978-3-642-57191-6 , p. 154.
  8. ↑ Juraj Gubi: Tea tree oil - one of nature's most effective means . In: Süddeutsche Zeitung. May 11, 2010.
  9. ↑ CF Carson, KA Hammer, TV Riley: Melaleuca alternifolia (Tea Tree) Oil: A Review of Antimicrobial and Other Medicinal Properties. In: Clin. Microbiol. Rev. 19 (1), 2006, 50-62. doi : 10.1128 / CMR.19.1.50-62.2006 , PMID 16418522 , PMC 1360273 (free full text).
  10. ↑ IB Bassett, DL Pannowitz, RS Barnetson: A comparative study of tea-tree oil versus benzoyl peroxide in the treatment of acne. In: Med. J. Aust. 153 (8), 1990, 455-458, PMID 2145499 .
  11. ↑ Shahla Enshaieh, Abolfazl Jooya, Amir Hossein Siadat, Fariba Iraji: The efficacy of 5% topical tea tree oil gel in mild to moderate acne vulgaris: a randomized, double-blind placebo-controlled study. In: Indian J. Dermatol. Venereol. Leprol. 73 (1), 2007, 22-25, PMID 17314442 , DOI: 10.4103 / 0378-6323.30646 .
  12. ↑ Huijuan Cao et al .: Complementary therapies for acne vulgaris In: Cochrane Database Syst. Rev. 1: CD009436, 2015, doi : 10.1002 / 14651858.CD009436.pub2 , PMID 25597924 , PMC 4486007 (free full text).
  13. ↑ a b Safety data sheet for tea tree oil (PDF) from Sanabio, accessed on July 29, 2017.
  14. ↑ BM Hausen et al .: Degradation products of monoterpenes are the sensitizing agents in tea tree oil. At the. J. Contact Dermat. 10/2/1999. Pp. 68-77. PMID 10357714
  15. ↑ C. Pirker and BM Hausen et al .: Sensitization to tea tree oil in Germany and Austria - a multicenter study by the German contact allergy group. In: J. Dtsch. Dermatol. Ges. 1, 8, 2003, pp. 629-634, doi : 10.1046 / j.1610-0387.2003.03727.x .
  16. ↑ Opinion on tea tree oil , SCCP (PDF), December 16, 2008.
  17. ↑ 7th meeting of the BfR Commission for Cosmetic Products, minutes of the meeting on May 19, 2011 (PDF), item 7: Essential oils / tea tree oil, p. 4 f.
  18. ↑ Derek V. Henley, Natasha Lipson, Kenneth S. Korach, Clifford A. Bloch: Prepubertal Gynecomastia Linked to Lavender and Tea Tree Oils In: New England Journal of Medicine. Volume 356, Number 5, 2007, pp. 479-485, doi : 10.1056 / NEJMoa064725 , PMID 17267908 .
  19. ↑ Katzenkiller tea tree oil on animal-health-online.de, accessed on May 6, 2011.
  20. ^ SA Khan, MK McLean, MR Slater: Concentrated tea tree oil toxicosis in dogs and cats: 443 cases (2002-2012). In: Journal of the American Veterinary Medical Association. Volume 244, number 1, 2014, pp. 95-99, doi : 10.2460 / javma.244.1.95 , PMID 24344857 .