Terpineol is an alcohol as in cajeput, eucalyptus, niaouli, tea tree, manuka, pine, petitgrain, marjoram, wild carrot seed, and ravensara.
Alcohols are the most therapeutically beneficial type of component in an essential oil, and have a low toxicity for safer use with fragile populations (like the elderly). Alcohols can be sensitizing when oxidized, so proper storage is important.
Links to Plants Containing Terpineol
The listings of research below represent a compilation of scientific articles found on the topic, with a very brief overview description of each article/study. This compilation of research articles does not necessarily imply that there are adequate results to demonstrate safe and/or effective human use of any herb listed.
ANTIMICROBIAL / ANTIBACTERIAL / ANTIFUNGAL
- Eucalyptus radiata was tested against Streptococci and Lactobacillus acidophilus. The major constituents have seasonal variance, impacting antibacterial strength, and include: 1,8-cineole, α-terpineol and limonene. From: Mahumane, G. D., van Vuuren, S. F., Kamatou, G., Sandasi, M., & Viljoen, A. M. (2016). Chemical composition and antimicrobial activity of Eucalyptus radiata leaf essential oil, sampled over a year. Journal of Essential Oil Research, 1-14. Link: http://dx.doi.org/10.1080/10412905.2016.1175386
- The antimicrobial effect of linalool, terpinen-4-ol, α-terpineol and 1,8-cineole as isolated constituents of cajuput oil was demonstrated. From: Cuong, N. D., Xuyen, T. T., Motl, O., Stránský, K., Presslova, J., Jedlickova, Z., & Serý, V. (1994).
- Klebsiella pneumoniae was highly sensitive to terpinen-4-ol and geraniol was likely the active antibacterial constituent of C. martinii EO. Melaleuca alternifolia (tea tree) , Pelargonium graveolens (geranium) and Cymbopogon martinii (lemongrass) were three essential oils tested, with these constituents. From: Murbach Teles Andrade, B. F., Nunes Barbosa, L., Bérgamo Alves, F. C., Albano, M., Mores Rall, V. L., Sforcin, J. M., … & Fernandes Júnior, A. (2016). The antibacterial effects of Melaleuca alternifolia, Pelargonium graveolens and Cymbopogon martinii essential oils and major compounds on liquid and vapor phase. Journal of Essential Oil Research, 28(3), 227-233. Link: http://dx.doi.org/10.1080/10412905.2015.1099571
- The antimicrobial effect of linalool, terpinen-4-ol, α-terpineol and 1,8-cineole as isolated constituents of cajuput oil was demonstrated. From: Cuong, N. D., Xuyen, T. T., Motl, O., Stránský, K., Presslova, J., Jedlickova, Z., & Serý, V. (1994). Antibacterial properties of Vietnamese cajuput oil. Journal of Essential Oil Research, 6(1), 63-67. From: Link: http://dx.doi.org/10.1080/10412905.1994.9698326
- Antibacterial abilities of 96 essential oils and their constituents were assessed. Marigold, ginger, jasmine, patchouli, gardenia, cedarwood, carrot seed, celery seed, mugwort, spikenard, and orange bitter oils along with the constituents of cinnamaldehyde, estragole, carvacrol, benzaldehyde, citral, thymol, eugenol, perillaldehyde, carvone R, and geranyl acetate were strongest against C. jejuni. Those most active against E. coli were oregano, thyme, cinnamon, palmarosa, bay leaf, clove bud, lemon grass, and allspice oils and the constituents: carvacrol, cinnamaldehyde, thymol, eugenol, salicylaldehyde, geraniol, isoeugenol, citral, perillaldehyde, and estragole. Those most active against L. monocytogenes were gardenia, cedarwood, bay leaf, clove bud, oregano, cinnamon, allspice, thyme, and patchouli and the constituents of cinnamaldehyde, eugenol, thymol, carvacrol, citral, geraniol, perillaldehyde, carvone S, estragole, and salicylaldehyde. Those most active against S. enterica were thyme, oregano, cinnamon, clove bud, allspice, bay leaf, palmarosa, and marjoram oils as well as thymol, cinnamaldehyde, carvacrol, eugenol, salicylaldehyde, geraniol, isoeugenol, terpineol, perillaldehyde, and estragole. From: Friedman, M., Henika, P. R., & Mandrell, R. E. (2002). Bactericidal activities of plant essential oils and some of their isolated constituents against Campylobacter jejuni, Escherichia coli, Listeria monocytogenes, and Salmonella enterica. Journal of Food Protection®, 65(10), 1545-1560.
- Basil (Ocimum basilicum) essential oil showed activity against eight important postharvest deteriorating fungi with the following constituents being significant: 1,8-cineole, linalool, camphor, α-terpineol, methyl chavicol, and eugenol. From: Barcelos, R. C., Jham, G. N., Dhingra, O. D., Mendonca, F. A., & Valente, V. M. (2013). Identification and Quantification of the Major Fungitoxic Components of the Brazilian Basil (Ocimum basilicum L.) Essential Oil. Journal of Food Research, 2(5), 124.
- The monoterpene alcohols in Douglas fir inhibited sheep and deer rumen microbial activity and included: α-terpineol, terpinen-4-ol, linalool, citronellol, and fenchyl alcohol. From: Oh, H. K., Sakai, T., Jones, M. B., & Longhurst, W. M. (1967). Effect of various essential oils isolated from Douglas fir needles upon sheep and deer rumen microbial activity. Applied microbiology, 15(4), 777-784.
- The a-terpinolene, trans-carlophyllene, and neryl acetate components of H. italicum (Roth) Don were effective against Micococcus luterus. From: Tundis, R., Statti, G. A., Conforti, F., Bianchi, A., Agrimonti, C., Sacchetti, G., … & Poli, F. (2005). Influence of environmental factors on composition of volatile constituents and biological activity of Helichrysum italicum (Roth) Don (Asteraceae). Natural product research, 19(4), 379-387
- The following essential oils and their constituents in order of effectiveness were active against pathogens in apple juice: against E. coli: carvacrol, oregano oil, geraniol, eugenol, cinnamon leaf oil, citral, clove bud oil, lemongrass oil, cinnamon bark oil, and lemon oil, and against S. enterica: melissa oil, carvacrol, oregano oil, terpeineol, geraniol, lemon oil, citral, lemongrass oil, cinnamon leaf oil, and linalool. From: Friedman, M., Henika, P. R., Levin, C. E., & Mandrell, R. E. (2004). Antibacterial activities of plant essential oils and their components against Escherichia coli O157: H7 and Salmonella enterica in apple juice. Journal of agricultural and food chemistry, 52(19), 6042-6048
- Terpinen-4-ol was active against candida species in the rat vagina. From: Mondello, F., De Bernardis, F., Girolamo, A., Cassone, A., & Salvatore, G. (2006). In vivo activity of terpinen-4-ol, the main bioactive component of Melaleuca alternifolia Cheel (tea tree) oil against azole-susceptible and-resistant human pathogenic Candida species. BMC infectious diseases, 6(1), 158.
- Tea tree oil and its terpinen-4-ol constituent showed strong antimicrobial activity against tested pathogens. From: Carson, C. F., & Riley, T. V. (1995). Antimicrobial activity of the major components of the essential oil of Melaleuca alternifolia. Journal of applied bacteriology, 78(3), 264-269.
- Tea tree oil and its components, 1,8-cineole, terpinen-4-ol, and α-terpineol demonstrated activity against Staphylococcus aureus. From: Carson, C. F., Mee, B. J., & Riley, T. V. (2002). Mechanism of action of Melaleuca alternifolia (tea tree) oil on Staphylococcus aureus determined by time-kill, lysis, leakage, and salt tolerance assays and electron microscopy. Antimicrobial agents and chemotherapy, 46(6), 1914-1920.
- This study described the antibacterial activity of tea tree oil and terpinen-4-ol against Staphylococcus aureus. From: Cuaron, J. A., Dulal, S., Song, Y., Singh, A. K., Montelongo, C. E., Yu, W., … & Gustafson, J. E. (2013). Tea Tree Oil‐Induced Transcriptional Alterations in Staphylococcus aureus. Phytotherapy Research, 27(3), 390-396.
- Tea tree oil and its terpinen-4-ol constituent were antiviral against influenza. From: Garozzo, A., Timpanaro, R., Bisignano, B., Furneri, P. M., Bisignano, G., & Castro, A. (2009). In vitro antiviral activity of Melaleuca alternifolia essential oil. Letters in applied microbiology, 49(6), 806-808.
- The study suggested tea tree’s antiviral activity against influenza was related to the inhibition of uncoating. From: Garozzo, A., Timpanaro, R., Stivala, A., Bisignano, G., & Castro, A. (2011). Activity of Melaleuca alternifolia (tea tree) oil on Influenza virus A/PR/8: study on the mechanism of action. Antiviral research, 89(1), 83-88.
- Tree tree oil and its terpinen-4-ol constituent were antifungal against multiple tested organisms. From: Oliva, B., Piccirilli, E., Ceddia, T., Pontieri, E., Aureli, P., & Ferrini, A. M. (2003). Antimycotic activity of Melaleuca alternifolia essential oil and its major components. Letters in applied microbiology, 37(2), 185-187.
- Cajeput oil and its isolated constituents of linalool, terpinen-4-ol, α-terpineol, and 1,8-cineole demonstrated antibacterial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa isolated from patients’ clinical material. From: Cuong, N. D., Xuyen, T. T., Motl, O., Stránský, K., Presslova, J., Jedlickova, Z., & Serý, V. (1994). Antibacterial properties of Vietnamese cajuput oil. Journal of Essential Oil Research, 6(1), 63-67.
- This review of research cited the dermatological uses for tea tree oil. It offers antioxidant, antimicrobial, and anti-inflammatory activities. Its key constituent, terpinen-4-ol, has also exhibited strong antimicrobial and anti-inflammatory actions. Clinical studies have demonstrated the use of tea tree for acne, seborrheic dermatitis, wound healing, and anti-skin cancer activities. From: Pazyar, N., Yaghoobi, R., Bagherani, N., & Kazerouni, A. (2013). A review of applications of tea tree oil in dermatology. International Journal of Dermatology, 52(7), 784-790.
- Terpene alcohols demonstrate local anaesthetic activity including linalool, terpinen-4-ol, menthol, and geraniol. From: Ghelardini, C., Galeotti, N., & Mazzanti, G. (2001). Local anaesthetic activity of monoterpenes and phenylpropanes of essential oils. Planta medica, 67(06), 564-566.
- Terpinen-4-ol from tea tree oil suppressed pro-inflammatory mediator production by activated human monocytes. From: Hart, P. H., Brand, C., Carson, C. F., Riley, T. V., Prager, R. H., & Finlay-Jones, J. J. (2000). Terpinen-4-ol, the main component of the essential oil of Melaleuca alternifolia (tea tree oil), suppresses inflammatory mediator production by activated human monocytes. Inflammation Research, 49(11), 619-626.
- Topical tea tree oil and terpinen-4-ol and α-terpineol affected oedema associated with the efferent phase of a contact hypersensitivity response in mice. From: Brand, C., Grimbaldeston, M. A., Gamble, J. R., Drew, J., Finlay-Jones, J. J., & Hart, P. H. (2002). Tea tree oil reduces the swelling associated with the efferent phase of a contact hypersensitivity response. Inflammation Research, 51(5), 236-244.
- Tea tree oil and its active component terpinen-4-ol were able to induce apoptosis of human melanoma cells. From: Calcabrini, A., Stringaro, A., Toccacieli, L., Meschini, S., Marra, M., Colone, M., … & Mondello, F. (2004). Terpinen-4-ol, the main component of Melaleuca alternifolia (tea tree) oil inhibits the in vitro growth of human melanoma cells. Journal of Investigative Dermatology, 122(2), 349-360.
- Terpinen-4-ol showed a depressant effect on the central nervous system and significant anticonvulsant activity. From: Sousa, D. P. D., Nóbrega, F. F., de Morais, L. C., & Almeida, R. N. D. (2009). Evaluation of the anticonvulsant activity of terpinen-4-ol. Zeitschrift für Naturforschung C, 64(1-2), 1-5.
- Essential oils and these constituents: terpinen-4-ol and 1-octene-3-ol, may modulate our mood through via GABA receptors and induce an anxiolytic effect. From: Aoshima, H., Oda, K., Orihara, Y., Hara, A., Shigemori, Y., Tan, N., … & Kiso, Y. (2009). Effects of essential oils on the response of GABAA receptors, sleeping time in mice induced by sleeping drug and plasma adrenocorticotropic hormone levels of rats. Aroma Research, 10(1), 58-54.
INSECTICIDAL / PESTICIDAL
- The insecticidal activities of essential oil extracts against the mosquito Culex pipiens molestus Forskål were determined. Extracts of Foeniculum vulgare (fennel) were the most toxic, followed by Ferula hermonis Boiss (in the carrot family), Citrus sinensis (orange), Pinus pinea (pine), Laurus nobilis (bay), and Eucalyptus spp. Terpineol and 1,8-cineole components were the most effective in preventing Culex pipiens molestus bites. From: Traboulsi, A. F., El‐Haj, S., Tueni, M., Taoubi, K., Nader, N. A., & Mrad, A. (2005). Repellency and toxicity of aromatic plant extracts against the mosquito Culex pipiens molestus (Diptera: Culicidae). Pest management science, 61(6), 597-604.
- Thymol, eugenol, pulegone, alpha terpineol and citronellal demonstrated insecticidal abilities related to insect enzyme activity and flight motor response. From: Waliwitiya, R. (2011). Plant-derived compounds: acute toxicity, synergism, and effects on insect enzyme activity and flight motor responses (Doctoral dissertation, Science: Biological Sciences Department).
- Certain monoterpenoids from O. majorana essential oil, including linalool, terpinen-4-ol and α-terpineol may be effective in a treatment for head lice. From: Yang, Y. C., Lee, S. H., Clark, J. M., & Ahn, Y. J. (2009). Ovicidal and adulticidal activities of Origanum majorana essential oil constituents against insecticide-susceptible and pyrethroid/malathion-resistant Pediculus humanus capitis (Anoplura: Pediculidae). Journal of agricultural and food chemistry, 57(6), 2282-2287.
- Tea tree oil and terpinen-4-ol were highly effective in reducing the human mite infection: sarcoptes scabiei. From: Walton, S. F., McKinnon, M., Pizzutto, S., Dougall, A., Williams, E., & Currie, B. J. (2004). Acaricidal activity of Melaleuca alternifolia (tea tree) oil: in vitro sensitivity of sarcoptes scabiei var hominis to terpinen-4-ol. Archives of dermatology, 140(5), 563-566.
- Both 1,8-cineole and terpinen-4-ol from tea tree oil were shown to inhibit acetylcholinesterase, which may be the reason for their insecticidal activity. From: Mills, C., Cleary, B. V., Walsh, J. J., & Gilmer, J. F. (2004). Inhibition of acetylcholinesterase by tea tree oil. Journal of Pharmacy and Pharmacology, 56(3), 375-379.
- Wild carrot seed oil was larvacidal against the mosquitos: Aedes aegypti, Culex pipiens, and Culex restuans Theobald. The most active constituents included: terpinolene, para cymene, and γ-terpinene. From: Muturi, E. J., Doll, K., Ramirez, J. L., & Rooney, A. P. (2018). Bioactivity of wild carrot (Daucus carota, Apiaceae) essential oil against mosquito larvae. Journal of medical entomology, 56(3), 784-789.
- Terpinen-4-ol, a monoterpene alcohol, killed bloodstream forms of the protozoa: T. brucei. From: Mikus, J., Harkenthal, M., Steverding, D., & Reichling, J. (2000). In vitro effect of essential oils and isolated mono-and sesquiterpenes on Leishmania major and Trypanosoma brucei. Planta Medica, 66(04), 366-368.
By: Kathy Sadowski