by
Marie Temmen
Common Name: Tea Tree (or Ti Tree)
Latin Binomial: Melaleuca alternifolia
Family: Myrtaceæ
Part Used: Leaves
Extraction Method: Steam Distillation
Country of Origin: Australia
Tea Tree essential oil is currently one of the most popular of the essential oils. Herb stores, aromatherapy catalogues, cosmetic counters and drug stores abound with products which contain Tea Tree. Indeed it has been referred to as the universal antiseptic and “first-aid in a bottle”. As professionals in the field of aromatherapy we have a responsibility to educate consumers in the purchase and use of these products. This article seeks to discuss the history of the product; explain its chemical composition; review clinical studies and explore selected uses of Tea Tree oil. It is hoped that, in the process, the reader will experience a renewed interest to learn more about this remarkable oil.
Tea Tree belongs to the Myrtaceæ family and the Melaleuca genus. This is a large plant family with more than 150 varieties of Melaleuca including Melaleuca cajuputi which yields Cajuput essential oil and Melaleuca quinquenervia which produces Niaouli essential oil. Tea Tree oil is known by the botanical name ofMelaleuca alternifolia (mela = black, leuca = white, with alternating leaves, hence alternifolia) and the common name of narrow leaved paperbark tree (so named because it resembles strips of paper peeling from the entire height of the trunk). The name Tea Tree has an interesting origin. In 1770 a British Naval force led by Captain James Cook landed in a part of Australia now known as New South Wales. They came upon groves of trees thick with sticky aromatic leaves which when boiled produced a spicy tea (well-known to the native inhabitants) which came to be known as Tea Tree. Today more than 200 years later these trees continue to flourish in the swampy low lying lands of New South Wales. lt is interesting that trees grown outside of this region do not produce the same quality tea tree oil we find so gentle and healing. This is yet another example of the role ecology plays in the production of a quality essential oil.
Tea tree has a complex chemical makeup with 97 plus identified components. These include the identification of four which have not previously been identified in plants They are: viridiflorene (1%), b-terpineol (.24%), with L Terpineol and allyhexanoate both present in trace amounts. Two major components which are central to the oil’s therapeutic potential are 1,8 cineole and Terpinen-4-ol. 1,8 cineole is an oxide which is largely responsible for the camphor-like scent found in eucalyptus oil and other oils of the Melaleuca genus. Its major effect is due to mucolytic properties. Therefore, it is useful for treatment of respiratory problems. Cineole is a skin irritant and for this reason should be present in small amounts in Tea Tree oil which is often applied directly to the skin. Terpinen-4-ol, on the other hand is desired in large amounts because it is responsible for the powerful yet gentle germicidal qualities Tea Tree possesses. As a member of the alcohol group it is a good anti-bacterial, anti-infective, and anti-viral.
Criteria known as the Australian Standard regulate the composition of Tea Tree oil. In 1985 the Australian Standard was revised and reissued stating that the oil should have a terpinen-4-ol content greater than 30% and a 1,8 cineole content less than 15%. Top quality Tea Tree oil should have a maximum cineole content of 5% and a minimum terpinen-4-ol content of 35-40%. Assumptions about chemical makeup can be inferred from smelling the oil. High quality oil should have a warm spicy antiseptic like scent with only a hint of camphor. Tea Tree oil which has a strong camphoraceous odor has probably been adulterated with large amounts of cineole and should not be used due to potential for skin irritation. Karen Mackenzie in her book, Tea Tree Oil Encyclopedia reminds consumers of the importance of buying tea tree oil labeled as Melaleuca alternifolia. She goes a step further and advocates that labels also list the percentage of 1,8 cineole and terpinen-4-ol.
The value of Tea Tree oil has been documented in clinical studies which date back to the original work conducted in 1923 by Dr. A. R. Penfold, an Australian government chemist. He found that Tea Tree leaves contained an essential oil which exhibited antiseptic and bacterial properties 13 times stronger than carbolic acid, the accepted standard of the time. In 1930 Mr. E. M. Humphrey published an article entitled “A New Australian Germicide”. He identified that Tea Tree oil’s disinfectant action on the typhoid bacilli was sixty times greater than that of ordinary hand soap. So important was Tea Tree in the 1940’s that it was standard issue in first-aid kits for army and navy personnel, especially those stationed in tropical regions. Following the war, research and interest declined and did not resume until the early 1960’s when Dr. E. F. Pena studied the value of Tea Tree oil in treating vaginal yeast infections. This has been followed by chemical studies treating a variety of ailments. Some of the most frequently cited are:
1972 – Foot Problems – Dr. M. Walker – “Journal of Current Podiatry” – Australia
1985 – Candida – Prof. Paul Beiache – Faculty of Medicine of Bobigny
1989 – Bacterial vaginosis- Dr. Donald Brown – Townsend Letters for Doctors
1990 – Acne – Prof R.S.C. Barneston – “Australian Journal of Pharmacy”
1991 – Dry skn – Division of Podiatry, Royal North Shore Hospital – Australia
In 1991, A. Shemesh MD (California) and William Mayo, PhD (New South Wales) conducted a six month study in which Tea Tree products such as cream and lozenges were used to treat a variety of problems including oral canker sores and non-specific dermatitis. The results of this research are reprinted inThursday Plantation Technical Manual available upon request from Thursday Plantation.
This brief review of clinical studies makes it clear that Tea Tree oil can indeed be used for a variety of problems. This oil is, in part, so unique because it is effective against viral, fungal and bacterial infections. It also works as an immuno-stimulant making it effective as a preventative measure. Julia Lawless in her book Tea Tree Oil: The New Guide To One Of Nature’s Most Remarkable Gifts, lists secondary properties which include: anti-inflammatory, analgesic, cicatrizant, insecticide, diaphoretic and expectorant. Several of the references at the end of the article provide an “A to Z” listing of health care applications. These uses range from treatment of bronchitis and thrush to use in hair and dental care products to first aid situations.
Tea Tree oil can be applied as a massage oil, in cream or lotion form, as a mouthwash, in hair care products, and as an inhalant. It can also be applied directly to the skin. Prior to direct application a skin test should be done to determine sensitivity. Several drops are applied to the back of the wrist and left for one hour, Should redness and irritation develop wash well with soap and water and discontinue future undiluted use. As with all essential oils internal use is not recommended and use by children, elderly people and pregnant women is discouraged. If accidental ingestion occurs do not induce vomiting. Have the individual drink large amounts of water and seek medical treatment immediately. Use of Tea Tree is not intended as a replacement for allopathic or homeopathic medical care.
Bibliography:
Lawless, Julia, Tea Tree Oil: The New Guide To One Of Nature’s Most Remarkable Gifts. Thorson’s Publishers, London 1944.
Mackenzie, Karen, The Tea Tree Oil Encyclopedia. Karedon Publisming, Great Britain 1995.
Olsen, C., Australian Tea Tree Oil Guide. Kali Press, Colorado 1991.
Price, Shirley, Aromatherapy Workbook. Thorsons Publishers, London 1993.
“Thursday Plantation Technical Manual”, Thursday Plantation, 1992
© 1997 National Association for Holistic Aromatherapy (NAHA) From Volume 7, Number 1Scentsitivity, the quarterly journal of the National Association for Holistic Aromatherapy (NAHA). Reprinted with permission of NAHA.