In part one we summarized 3 very interesting peer-reviewed published studies on the anti-cancer activity of essential oils currently being researched. There was so much to say, however, that we had to split it into to articles! Here's part 2, also with some really interesting reading on the latest science of essential oils and their anti-cancer activity.


Tea Tree Leaves and Flowers

These are two studies specifically noting the anticancer activity of Tea Tree oil in skin cancers, and that of Thyme oil in cancers of the oral cavity.

Tea Tree and Melanoma

It seems that tea tree essential oil may have the potential to combat melanoma, according to a study published in Planta Medica (2011 Jan;77(1):54-6. Epub 2010 Jun 17) titled "Tea tree oil might combat melanoma." The research was performed at the Department of Technology and Health, Istituto Superiore di Sanità, Rome, Italy. The abstract really speaks for itself:

"In this study we present new data from experiments focused on the antitumor activity of tea tree oil (TTO), an essential oil distilled from Melaleuca alternifolia. TTO proved to be capable of inhibiting the growth of melanoma cells and of overcoming multidrug resistance (MDR), as we reported in our previous study... The results reported herein indicate that TTO and its main active component, terpinen-4-ol, can also interfere with the migration and invasion processes of drug-sensitive and drug-resistant melanoma cells."

Note that not only can tea tree oil potentially inhibit the growth of melanoma skin cancer cells, but may also be effective in cases where the cells are resistant to currently used anti-cancer drugs.

Tea Tree's Anti-Cancer Activity, pt 2




Tea Tree in bloom The Tea Tree plant in bloom.



Another study seems to confirm these actions of tea tree oil. Published in the journal of Cancer Chemotherapy and Pharmacolgy (2010 Nov;66(6):1095-102) was a study titled "Inhibition of established subcutaneous murine tumour growth with topical Melaleuca alternifolia (tea tree) oil", performed at the School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia.

Researchers state in their abstract: "Here, we show for the first time that topical Melaleuca alternifolia (tea tree) oil (TTO), abundant in terpenes, has in vivo antitumour activity."

"Four, daily, topical treatments of 10% TTO/DMSO (Ed. Note: this is a mixture of DMSO and Tea Tree Oil, to enhance the absorption and penetration of the Tea Tree) regressed subcutaneous AE17 mesotheliomas... for a period of 10 days and significantly retarded the growth of subcutaneous B16-F10 melanomas...Furthermore, we show that topical 10% TTO/DMSO caused an influx of neutrophils and other immune effector cells in the treated area, with no evidence of systemic toxicity."

They conclude by noting: "TTO combined with an effective carrier significantly inhibited the growth of aggressive, subcutaneous, chemo-resistant tumours...Taken together, these findings highlight the potential of topical TTO as an alternative topical anti-tumour treatment."

Thyme Oil and Mouth Cancers

Thyme Herb Thyme herb, the source of several potent essential oils.

Interestingly, and unknown to us, oral cavity squamous cell carcinoma accounts for 2% to 3% of all malignancies and has a high mortality rate. Published in Anticancer Research (2011 Jan;31(1):81-7) was a study titled: "Cytotoxicity of Thymus vulgaris essential oil towards human oral cavity squamous cell carcinoma" performed at the Department of Otorhinolaryngology, Head and Neck Surgery, University of Heidelberg, Germany.

The majority of anticancer drugs are of natural origin. However, it is unknown whether the medicinal plant Thymus vulgaris L. (thyme) is cytotoxic towards head and neck squamous cell carcinoma (HNSCC). Cytotoxicity of thyme essential oil was investigated on the HNSCC cell line, UMSCC1. The IC₅₀ of thyme essential oil extract was 369 μg/ml. Moreover, we performed pharmacogenomics analyses.

Genes involved in the cell cycle, cell death and cancer were involved in the cytotoxic activity of thyme essential oil at the transcriptional level. The researchers concluded that "Thyme essential oil inhibits human HNSCC cell growth. Based on pharmacogenomic approaches, novel insights into the molecular mode of anticancer activity of thyme are presented."

There are now several oils that have been documented to combat skin cancers, which we have recently presented in blog posts, including Sandalwood and Rosewood oils. We'll continue to make these updates via our blog and newsletter as new research is published!