Terpinolene which is otherwise known as δ-terpinene is an organic compound present in the essential oils of apple, hemp, lilac, cumin, tea tree, lemon, sage, marjoram, rosemary, pine and cypress. It is one of the isomers of terpinene.

It is a monoterpene with the chemical formula C₁₀H₁₆. It is also referred by various other names such as iso-terpinene, 1, 4, 8 – terpadiene, etc.

Attributes of Terpinolene:

Terpinolene is colorless clear liquid which is characterised by fresh pleasant woody aroma. It owns fresh pine citrus flavor. Terpinolene present in hemp attribute to the aroma of the plant.

The therapeutic attributes of Terpinolene includes antibacterial, antifungal, anticancer, antioxidant and sedative properties.

Antimicrobial activity:

Terpinolene show antibacterial and antifungal activities against strains of various bacteria and fungi. A study titled “Essential Oil Composition and Antimicrobial ActivityofDiplotaenia damavandica” was carried out to investigate the antibacterial and antifungal activity of the essential oil obtained from the root, seeds and leaves of Diplotaenia damavandica and their constituents.

It was found that Terpinolene which is one of the main components of the essential oil obtained from the leaves exhibit high antibacterial activity against Bacillus subtilis, Enterococcus faecalis, Escherichia coli, Staphylococcus epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa. Further, it was also active against fungi namely Aspergillus Niger, Candida albicans and Saccharomyces cerevisiae.

Anticancer and Antioxidant effect:

Terpinolene exhibit antioxidant and anticancer activities. In 2013, a study titled “Anticancer and antioxidant properties of terpinolene in rat brain cells.” the potential of terpinolene as an antioxidant and as an antiproliferative agent against brain tumor cells in rats was investigated.

When terpinolene was administered to rats with brain tumor, it was found that Terpinolene cause remarkable reduction in the proliferation of primary rat neurons and in N2a neuroblastoma cells.

Further, Terpinolene at concentrations above 50 mg L^-1 increased Total oxidative stress and antioxidant capacity in Neurons and in N2a neuroblastoma cells. Terpinolene did not cause any destruction to the genetic materials of the cells in rat neurons and N2a neuroblastoma and so it was not genotoxic in both cell types.

Altogether, it was brought into light that Terpinolene exhibit antioxidant, antiproliferative and non-genotoxic abilities.

AKT or Protein Kinase B (PKB) is a kinase enzyme that plays a vital role in cellular processes, especially in cell proliferation. The activation of AKT is connected with many types of cancers as it increases cell proliferation and suppresses apoptosis.

According to the study “Terpinolene, a component of herbal sage, downregulates AKT1 expression in K562 cells” it was made clear that Terpinolene found in the oils of rosemary and clary sage exhibited potential activity against cancer by hindering the cell proliferation through reduction of the protein expression of AKT1 in leukemia K562 cells.

Sedative property:

Terpinolene is characterised by its sedative property. A study “Sedative effects of vapor inhalation of the essential oil of Microtoena patchoulii and its related compounds” published in 2011 in Journal of natural medicines was focused on the sedative effects produced in rats by inhaling the vapors of the essential oil of Microtoena patchoulii and its constituents, namely Terpinolene, 1-octen-3-ol, patchouli alcohol and methyl salicylate.

It was discovered that the essential oil reduced the locomotor activity of the rats and the same was observed when Terpinolene, 1-octen-3-ol, patchouli alcohol was administered individually through inhalation to the rats. Further, terpinolene also increased the sleeping time in rats by suppressing the central nervous system.

In another research article titled “The sedative effect of inhaled terpinolene in mice and its structure-activity relationships.” it was revealed that Terpinolene when inhaled by rats that have olfactory impairment (adisorder in sensing the smell) produced sedative effects after its absorption through the nasal cavity.

Heart Disease:

Terpinolene together with vitamin A and vitamin E prevent the oxidation of bad cholesterol Low Density Lipoprotein (LDL) and thus it is helpful in the treatment of Heart diseases. This is evident from the study “The monoterpene terpinolene from the oil of Pinus mugo L. in concert with alpha-tocopherol and beta-carotene effectively prevents oxidation of LDL.”

Reference Links:

1. Essential Oil Composition and Antimicrobial Activity of Diplotaenia damavandica
2. Anticancer and antioxidant properties of terpinolene in rat brain cells
3. Terpinolene, a component of herbal sage, downregulates AKT1 expression in K562 cells
4. Sedative effects of vapor inhalation of the essential oil of Microtoena patchoulii and its related compounds
5. The sedative effect of inhaled terpinolene in mice and its structure-activity relationships
6. The monoterpene terpinolene from the oil of Pinus mugo L. in concert with alpha-tocopherol and beta-carotene effectively prevents oxidation of LDL.