TEA TREE Essential Oil

Melaleuca Alternifolia

Family: Myrtaceae contains 230 species, mostly native to Australia

Other Tea Tree species: M. dissitiflora, M. linarifolia, M. uncinate

Given the variety of species, the International Standard has set a requirement on the chemical and physical criteria of the oil composition to be called Tea Tree and not the species of location or origin. Commercial Tea Tree oil (TTO) will have 30-40% terpinene-4-ol or more but not lower which ensures the antimicrobial activity. Two more chemotype compositions are terpinolene and four 1,8-cineole.

Safety data on Tea Tree Oil states non-toxic, non-irritant, and non-sensitizing from the Aromatherapy Encyclopedia by Judith Law.

Tea Tree is mostly grown in Australia and is known as paperbark tree. The native habitat for cultivating tea tree is low-lying subtropical swamy coastal ground. The trees can grow up 5-8 meters. A tree older than 3 years will have fluffy white flowers. Most plants are harvested within 1-3 years. Leaves and terminal branches produce the oil from stream distillation. Kanuka and manuka derived from the New Zealand plants of Kunzea ericoides and Leptospermum scoparium are known as TTO (Carson et al., 2006, Clinical Microbiology Reviews, vol 19(1), 50-62). Doi: 10.1128/CMR.19.1.50-62.2006

History: Bundjalung Aborigines used crushed tea tree leaves to inhale for coughs and colds or sprinkled on wounds. Penfold wrote in 1920-the 30s about assessing the compounds of TTO for their antimicrobial effects. Oil was extremely popular in World War II. Other research on TTO as an anti-bacterial started in the 1940s and antimicrobial activity from the early 1990s.  Plantations were later established in the 1970-80s and today are in Western Australia, New South Wales, and Queensland (Carson et al., 2006, Clinical Microbiology Reviews, vol 19(1), 50-62). Doi: 10.1128/CMR.19.1.50-62.2006

Each oil consists of many active constituents (chemical makeup) that are unique to just that plant, tree, or shrub. Various parts of that plant (stem, leaves, bark, resin, flowers) are used in making oil and can contain different active constituents designed by nature for protection and growth. The location in the world where the plant is grown affects its therapeutic nature as well. The mixture of the chemistry of the plant gives it the aroma.

The major active chemical constituents of Tea Tree oil are Terpinen-4-ol at 41.9%, gamma-terpinene 26.3%, and alpha-terpinene at 11.9%.

The following are research studies done on Tea Tree essential oil.

• Anti-bacterial Effects

Aquaculture plays a key role in worldwide food production. The intensive and stressful raising of farmed fish creates a bacterial infection called an epizootic ulcerative syndrome. The protective effects of TTO were studied to stop infections caused by Aeromonas hydrophilia (gram-negative pathogen) in silver catfish. TTO was found to be able to stop the alterations of the purinergic enzymes that regulate ATP, ADP, and Ado. TTO was also able to make the innate immune response better through anti-inflammatory cytokine levels during the infections. TTO is known for its anti-inflammatory effect. The bacteria increased the pro-inflammation cytokines and TTO was able to interfere with that process (Baldissera et al., 2017, Microbial Pathogens, vol 109, 61-66).

DOI: 10.1016/j.micpath.2017.05.026

Silver catfish infected with Aeromonas hydrophilia using treatment of TTO (50 mL with ethanol) was studied for oxidative stress and for the first-time effects on hepatic enzymes of the cholinergic and adenosinergic system. TTO prevented alterations in the adenosinergic system and damage done by lipids and proteins. No change was seen in the AChE activity (Baldissera, et al., 2017, Fish & Shellfish Immunology, vol 61, 1-8).

DOI: 10.1016/j.fsi.2016.12.016

• Anti-cancer Effects

Antitumor activity with EOs was investigated with melanoma, and lung cancer cells without toxic effects on fibroblasts. TTO compound Terpinen-4-ol at 37.5% was able to synergize with the target therapy for melanoma. Out of 61 oils, TTO, Lavender, Cypress, Grapefruit, Scots pine, and Siberian Pine were most effective in reducing tumor cell proliferation without affecting normal cells in melanoma and lung carcinoma but not effective with breast and colon cells (Martile et al., 2021, Cell Death Discover, vol 7, 127). DOI: 10.1038/s41420-021-00510-3

• Anti-fungal Effects

Invasive fungal would infections (IFIs) have caused complications and death in trauma patients despite excellent trauma care. Thirteen clinical isolates from IFIs were studied to evaluate TTO. The safety of wound application of TTO levels was assessed in vitro. The kill-time assays showed fluctuation between isolates but showed significant cytotoxicity, demonstrating TTO has antifungal activity against IFIs (Homeyer et al., 2015, Medical Mycology, vol 53, 285-294). DOI: 10.1093/mmy/myu072

• Anti-parasites

The most common ectoparasite are Demodex mites that infect humans and are found on skin extending to the eye. The most active ingredient in TTO for killing these mites was Terpinen-4-ol in a low concentration of 1%. This compound worked better by itself than in combination with other compounds found in TTO. Terpinene-4-ol can be formulated with acaricides (pesticides) to treat ocular and cutaneous diseases caused by demodicosis (Tighe et al., 2013, Translational Vision and Science Technology, Vol 2(7), article 2). DOI: 10.1167/tvst.2.7.2

•  TTO and Immune System

Part of the immune system’s inflammatory components is tumor necrosis factor-alpha (TNF-alpha), Interleukin (IL)-beta, IL-8, IL-10, and prostaglandin E2 (PGE2). They are classified as cytokines and are activated by lipopolysaccharides (LPS). The TTO compound Terpinen-4-ol was able to reduce the production of inflammatory cytokines in 40 hours (Hart et al., 2000, Journal of Inflammatory Research, vol 49(11), 619-626). DOI: 10.1007/s000110050639 PMID 11131302

Trypanosoma evansi is a parasite in the blood of cattle creating a disease called Surra and is transmitted by biting flies. Surra is characterized by anemia, weight loss, recurrent fever, and death in a wide variety of domestic animals, including horses, cattle, buffalo, and camels, in Asia, Africa, and South America.  A study was conducted on this parasite in rats and TTO. The rats were orally given 1 mL of TT for three days. Blood samples shown TTO was able to modulate the immunoglobulins and cytokines profiles and the course of the parasite. TTO was not toxic to the liver or kidneys (Baldissera et al., 2014, Research in Veterinary Science, vol 96, 501-506). DOI: 10.1016/j.rvsc.2014.03.013

Immune modulatory effects of TTO concentrate were studied on the human THP1 (monocyte from leukemia cell line) and murine RAW264.7 (myeloid leukemia cell lines) as models for macrophage-like cells. TTO concentrate levels were measured not to affect either the survival or proliferation of these cell lines in vitro. Lipopolysaccharide (LPS)-induced production of cytokines (IL-6, TNFα, IL-10, GM-CSF, IFNγ, and IL-3) levels were examined from the myeloid cell lines. Many of the LPS-inducible cytokines could be significantly inhibited by the TTO concentrate. TTO concentrate inhibited the LPS-induced activation of IκB phosphorylation, nuclear factor (NF)-κB signaling, inducible nitric oxide synthase, protein expression, and nitric oxide production. These results demonstrated that TTO concentrate exerts its immunomodulatory effects by inhibiting NF-κB signaling activation and levels of cytokine production by macrophage-like cell lines (Low et al., 2015, International Immunopharmacology, vol 26, 257-264).

DOI: 10.1016/j.intimp.2015.03.034 

• Stress & TTO

Stress can lead to poor sleep and compromised immune function. A blend of lemon, tea tree, eucalyptus, and peppermint was used as an aromatherapy treatment for testing stress, sleep, and immune function. The experimental group (30) wore a pendant daily and slept near an aromatherapy stone at night for four weeks. The experimental group had significantly lower perceived stress and depression than the control group. They also showed significantly higher sleep quality. The two groups did not differ in autonomic nervous system activity, blood sugar levels, or immune status (Lee et al., 2017, European Journal of Integrative Medicine, vol 12, 79-86).

• Plaque and Chronic Gingivitis

A study was conducted with 49 non-smokers with chronic gingivitis and TTO. They were given TTO gel, chlorhexidine gel, or a placebo gel for brushing twice a day. They were assessed at four and eight weeks. The TTO group had a significant reduction in the Papillary Bleeding Index and the Gingivitis Index scores. TTO did not show a reduction in the plaque scores (Soukoulis & Hirsch, 2004, Australian Dental Journal, AromaticScience.com

Tea Tree is part of my Immune 8 formula. You may check out other blogs on the other essential oils in the Blend

To Your Health & Happiness,

Dr. Margie