Alpha-terpineol


Alpha-terpineol is one of the isomers of terpineol, which is a monoterpene alcohol found in Pine oil, Cajeput oil and petitgrain oil. It is present in the barbed skull cap, Lapsang souchong tea, a black tea from China. When the leaves of Lapsang souchong is dried using the pine smoke, alpha terpineol and longifolene are produced.

Alpha-terpineol is the major constituent of the mixture of the isomers that together form terpineol. Its molecular formula is C10H18O and it is also referred by various other names such as 1-alpha-terpineol, DL-alpha-terpineol, alpha terpineol sodium salt and so on.

Attributes of alpha-terpineol:

It is a colorless oily liquid to solid with floral lilac aroma. It owns sweet lime taste. It is used as a flavoring agent due to its distinctiveness. It is used as intermediates, solvents and as a fragrancing agent in perfumery.

Therapeutic properties of alpha-terpineol:

Antimicrobial activity:

Alpha-terpineol exhibits antibacterial activity. In the study “Antimicrobial effect of linalool and α-terpineol against periodontopathic and cariogenic bacteria” it was established that alpha terpineol showed antimicrobial activity against periodontopathic and cariogenic bacteria.

According to the study, “The proposed mechanism of bactericidal action of eugenol, alpha-terpineol and gamma-terpinene against Listeria monocytogenes, Streptococcus pyogenes, Proteus vulgaris and Escherichia coli”, it was found that alpha terpineol was active against the bacteria Listeria monocytogenes, Streptococcus pyogenes, Proteus vulgaris and Escherichia coli.

Antifungal activity:

Alpha terpineol possesses antifungal effect against a range of fungi. It is evident from the study “Antifungal activity of the components of Melaleuca alternifolia (tea tree) oil” that alpha terpineol present in Melaleuca alternifolia is active against a range of fungi with minimum inhibitory concentrations and minimum fungicidal concentrations.

In another study titled “Antifungal activity of citral, octanal and alpha-terpineol against Geotrichum citri-aurantii”, it is also made clear that alpha terpineol exhibit antifungal activity against Geotrichum citri-aurantii.

In the book named “Candidiasis—Advances in Research and Treatment: 2012 Edition: Scholarly Paper”, it is mentioned that alpha terpineol present in the essential oil of Artemisia princeps pamp., reduces the growth of Candida albicans and Gardnerella vaginalisis.

Anti-inflammatory effect:

Alpha terpineol is also acclaimed for its anti-inflammatory effect, which is evident from the study “Characterization of α-Terpineol as an anti-inflammatory component of Orange Juice by in Vitro Studies Using oral Buccal Cells”. In this study, it was found that alpha terpineol found in the orange juice possess anti-inflammatory effect by inhibiting the formation of pro-inflammatory cytokine IL-6.

In another study “The water-soluble components of the essential oil of Melaleuca alternifolia (tea tree oil) suppress the production of superoxide by human monocytes, but not neutrophils, activated in vitro”, it was made clear that alpha-terpineol suppress the production of silver oxide and regulates the functioning of cells during inflammation.

Anti-proliferative effect:

A study titled “Antiproliferative activity of essential oils derived from plants belonging to the Magnoliophyta division” was conducted to test the anti-proliferative effects of the essential oils from different plants in Magnoliophyta family. It was determined that alpha terpineol and caryophyllene present in the essential oils exhibited remarkable anti-proliferative effects on human erythroleukemic K562 cells.

Anticancer activity:

Alpha-terpineol exhibits anticancer activity against human cell lung carcinoma. According to the study “Alpha Terpineol: A Potential Anticancer Agent which Acts through Suppressing NF-κB Signalling” the cytotoxic effect and anticancer activity of alpha terpineol was examined. It was found that alpha terpineol when treated on human cell lung carcinoma reduces the growth of the tumour cells through suppression of NF-κB pathway.

Skin penetration enhancement:

In a study “Terpenes and the Lipid–Protein–Partitioning Theory of Skin Penetration Enhancement”, it was reported that alpha terpineol acts as a skin penetration enhancer by enhancing the permeability of skin to lipid soluble compounds.

Reference Links:

  1. Terpineol by Wikipedia
  2. Antimicrobial effect of linalool and α-terpineol against periodontopathic and cariogenic bacteria
  3. The proposed mechanism of bactericidal action of eugenol, alpha-terpineol and gamma-terpinene against Listeria monocytogenes, Streptococcus pyogenes, Proteus vulgaris and Escherichia coli
  4. Antifungal activity of citral, octanal and alpha-terpineol against Geotrichum citri-aurantii
  5. Characterization of α-Terpineol as an Anti-inflammatory Component of Orange Juice by in Vitro Studies Using Oral Buccal Cells
  6. Alpha Terpineol: A Potential Anticancer Agent which Acts through Suppressing NF-κB Signalling