What is Turmeric Essential Oil useful for in a Clinical Aromatherapy setting?

The Latin name for this plant is Curcuma longa Linn and it is a member of the Zingiberaceae family (the same as Ginger oil). Native to the Indian subcontinent and Southeast Asia, it is widely used in cooking. It is also cultivated in China and the plant has rhizomes roots very much like ginger except the turmeric rhizome root is a deep orange colour on the inside. The leaf of turmeric is also much wider than ginger but they are of course part of the same plant family, so we should see some similarities.

Turmeric has become very "fashionable" recently as a herbal supplement and cooking ingredient. There are numerous companies selling supplements and remedies that purport a cure all. It is its anti-inflammatory action, thanks to the main active ingredient of curcumin that have interested people suffering from inflammatory diseases. I recently put out a query on the Complementary Health Professional Facebook forum to see who had been using it successfully as an essential oil and how and people have also responded about how they are using the supplement too. One person said she uses it instead of Ibuprofen successfully to avoid digestive problems associated with ibuprofen; however, prolonged use of turmeric has been associated with incidences of ulcers, hyperplasia and inflammation in the forestomach, cecum and colon (Imrahim et al 2018), so it clearly needs careful monitoring. I have bought some rather expensive turmeric supplements for my own mother who has bursitis in her right hip, but there was no pain relief after 30 days.

Curcumin has several other biological activities including being anti-carcinogenic, anti-infectious, antioxidant, anti-apoptic and is vulnerary. People have reported adding turmeric to honey for wound healing. However, all of these studies were either topical dressing using the powdered turmeric or given orally. This article is about the essential oil and how aromatherapists might use it in a clinical setting so I wanted to find out what is in the oil when it has been distilled. I started with a GC/MS analysis of the essential oil that had been obtained via hydro-distillation from the rhizomes.

The essential oil distilled was used to test antimicrobial activity and was effective against Candida albicans, Staphylococcus aureus and Aspergillus niger. It was concluded that the high turmerone content was the reason (Singh et al 2011). The other constituent in high concentration in this GC/MS analysis is curlone. There are lesser quantities of curcumene, beta-sesquipellandrene, beta-bisabolene, alpha-phellandrene, beta-farnesene and eucalyptol.

Another GC/MS result was obtained from an essential oil distilled from the leaves as well as the fresh rhizomes by hydro-distillation. The leaf oil gave α–phellandrene as its main constituents and other desirable chemical constituents like eucalyptol, terpinolene, terpinene, β-pinene, zingiberene were also found in the leaf essential oil of both genotypes. The root oil yielded tumerone as its main constituent. In fact, from GC-MS analysis of essential oil, tumerone was identified as the major compound occupying maximum peak area in all genotypes of turmeric from different agro-climatic zones. Percentage of tumerone varied from 35.24% to 44.22% among all five elite genotypes (Akbar et al 2015).

In this result, the other consituents in the rhizome essential oil were eucalyptol, α-Curcumene, α-Zingiberene, Curlone, Bisabolene, Sesquiphellandrene, α-Pellandrene and δ-Cymene. I will put these in a table with their known therapeutic actions below: