Greece’s Natural Beauty: Thyme and its Medicinal Benefits

For the past couple of weeks, I have been on the island of Karpathos, Greece, visiting family. In the cool mornings on the countryside of Afiartis, I like to go jogging. While jogging, I see bushes of purple plants lining the dirt roads and far up on the hills. These bushes contain the thyme herb that grows so commonly in Greece, as well as in the rest of the Mediterranean. This plant can grow as either bushes that do not exceed 50 cm, or as creeping plants with rooting twigs. While bending down to pick up a couple of its flowers, I can smell its strong aromatic fragrance. This aroma is a result of the many glandular hairs found throughout the plant. Whenever these hairs are broken, as when they are plucked by a passersby, the aromatic smell is released. Additionally, this production of essential oils proves to be an adaptive advantage, because the plant can lack water in its dry environment. When these essential oils evaporate, they surround the plant, creating a saturated environment, which decreases water loss. 

Origin of the Word

From ‘My Big Fat Greek Wedding’ it has been said that the root of every word is Greek. As this might not hold true for everything, it certainly does for the word ‘thyme’. However, the exact origin of the word is not exactly known, with conflicting sources that describe the origin of the word. Some say that it originates from the Greek word, thymos, which means courage, since thyme used to be used as a symbol of bravery. However, this word has a second meaning. It originally referred to smoke, as thyme used to be burnt in temples. Furthermore, another source claims that the origin of the word could be from the Greek word thyo, which means sacrifice, since it was used historically in temples for sacrifices.

Taxonomy

There are many species of thyme that exist throughout the world. Taxonomically, the thyme herb belongs to the family Lamiaceae, similar to oregano. Common thyme is referred to as Thymus vulgaris. Another species of thyme commonly found in Greece is wild thyme or T. serpyllum, which is the thyme pollinated by bees for honey. Other species of thyme are T. citriodorus, T. herba-barona, T. praecox, and T. pseudolanuginosus.

Bushes of thyme on my morning jog. Afiartis, Karpathos, Greece.

Bushes of thyme on my morning jog. Afiartis, Karpathos, Greece.

Thyme has many known culinary and aromatherapy uses. However, throughout history, it has also demonstrated remarkable medicinal properties. With current research, these old properties are being revisited for their potential use in medicine today. When used in medical practice, it is not the dried herb that is used, but instead its essential oil. With every thyme essential oil, there are different chemical compounds, named phenols, present at different concentrations. The two principal phenols of this essential oil are thymol and carvacrol. Below I will describe the medicinal uses that this essential oil exhibits.

Antiseptic

While most people have heard of the antiseptic mouthwash, Listerine, many may not know that one of its main components is thymol, the compound commonly present in thyme essential oils. In 1879, it was created by Dr. Joseph Lawrence and pharmacist Jordan Wheat Lambert. Their invention was inspired by Joseph Lister, who was the pioneer of antiseptic techniques in medicine by recommending hand-washing procedures before and after surgery. This simple act significantly reduced mortality rates for medical procedures. There have been several uses for Listerine after its creation. Throughout the 1920s, it was used to freshen breath, cure halitosis, clean floors and reduce dandruff. From the middle of the 1970s to the 1980s, it finally started being used for oral hygiene to prevent plaque and gingivitis.

Listerine

Listerine

Antifungal and Antibacterial Effects

Throughout time, thyme essential oil has been observed for having antifungal and antibacterial properties, even though the mechanism behind it was not fully understood. Today it is known that these properties are due to the thymol and carvacrol present in the herb. The antifungal properties of thyme have been studied in Pakistan and it was shown that T. serpyllum had a moderate fungicidal effect on the fungi Fusarium monoliforme, Alternaria species, Candida albicans, Candida glabarata and Fusarium solani. Many studies have also pointed to its antibacterial use in common bacteria. While showing susceptibility to fungi, and easily treatable bacteria, it has also been proven to be effective against multiple drug resistant bacteria. In a Polish study, the activity of thyme oil was tested against multiple drug resistant Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, Escherichia coli and Pseudomonas aeruginosa. When the susceptibility to thyme oil was measured against all of these bacteria, it was shown that almost all strains were sensitive to thyme oil in low concentrations. With the progressive increase of antibiotic resistance today, this finding may have significant implications. Perhaps we will need to go back to more natural methods of eliminating these antibiotic resistant bacteria.

Foodborne Pathogen Control

Because of its antibacterial effects, recent studies have demonstrated that thyme essential oil displayed antibacterial properties against the foodborne pathogens Shigella sonnei and Shigella flexneri. The essential oil has also been shown to prevent food from spoiling due to other foodborne bacteria such as Salmonella, Enterococcus, Escherichia, and Pseudomonas species. In one study performed in Brazil, Listeria monocytogenes growth in beef was decreased with the use of thyme essential oil using vapor activity or an edible gelatin coating on the beef.

Thyme essential oil

Thyme essential oil

Effects on Inflammation

In past studies, it was demonstrated that thyme essential oil possessed anti-inflammatory properties by inhibiting cyclooxygenase-2 (COX-2), which is responsible for stimulating the production of prostanoids (which include prostaglandins, prostacyclins, and thromboxanes), and cytokines. These are proteins involved in the inflammatory process. In another study conducted in Brazil, it was also noted that thyme essential oil displayed effects towards the movement of white blood cells to the injury site, by inhibiting chemotaxis, which is the movement of white blood cells in response to chemicals. This further contributes to thyme oil’s anti-inflammatory properties.

Antioxidant Effects

When oxygen is metabolized in the body, there are “free radicals” that can be produced, such as hydroxyl, superoxide radicals or hydrogen peroxide, which result in oxidative damage to DNA. In past experiments, thyme oil and its phenol have been evaluated for their antioxidant effects. It was shown that the oil had potential of scavenging nitric oxide and free radicals, as well as donating hydrogen ions. In another study performed in Moscow, Russia, thyme essential oil significantly decreased lipid peroxidation products in the blood, liver, and brain of mice and improved their resistance to oxidation. These antioxidant effects are due, yet again, to the thymol and carvacrol present in the oil of thyme. In addition, the amount of antioxidant activity occurs due to the ratio of the two phenols present in the essential oil, which for thyme essential oil is 15 to 1.

Chemical structures of thymol and carvacrol

Chemical structures of thymol and carvacrol

Dosage and Reactions

After reading all of these medical benefits, one might choose to start using thyme essential oil to treat minor illnesses. However, be aware that the essential oil should not be directly applied to skin. It should first be diluted in a carrier oil, which is a vegetable oil from seeds, kernels or nuts. The use of this essential oil may cause an allergic reaction or inflammation. Before use, first apply a small portion to the skin to test for the possibility of allergic reactions. The essential oil should not be administered orally or taken internally in any form. At this time, there are no known toxic doses for the essential oil. However, you should always consult your doctor or someone familiar with essential oils before starting treatments.

References

Alinkina, E. S., Misharina, T. A., & Fatkullina, L. D. (2013). Antiradical properties of oregano, thyme, and savory essential oils. Apllied Biochemistry and Microbiology, 49(1), 82-87. doi: 10.1134/S000368381301002X

Chandra, K., Salman, A. S. Mohd, A., Sweety, R., & Ali, K. N. (2015). Protection against FCA induced oxidative stress induced DNA damage as a model of arthritis and in vitro anti-arthritic potential of Costus speciosus rhizome extract. International Journal of Pharmacognosy and Phytochemical Research, 7(2), 383-389. Retrieved from http://ijppr.com/PDF/7/IJPPR,Vol7,Issue2,Article34.pdf

de Oliveira, M. M. M., Brugnera, D. F., & Piccoli, R. H. (2013). Essential oils of thyme and rosemary in the control of Listeria monocytogenes in raw beef. Brazilian Journal of Microbiology, 44(4), 1181-1188. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/24688509

Eustice, C. (2014). Cyclooxygenase: COX-1 and COX-2 explained. Retrieved July 1, 2015, from http://osteoarthritis.about.com/od/osteoarthritismedications/a/cyclooxygenase.htm

Fachini-Queiroz, F. C., Kummer, R., Estevão-Silva, C. F., de Barros Carvalho, M. D. Cunha, J. M., Grespan, R., Bersani-Amado, C. A., & Cuman, R. K. N. (2012). Effects of thymol and carvacrol, constituents of Thymus vulgaris L. essential oil, on the inflammatory response. Evidence-Based Complementary and Alternative Medicine, 2012, 1-10. doi: 10.1155/2012/657026

Fine, D. H. (2010). Listerine: past, present and future – A test of thyme. Journal of Dentistry. 38(S1), S2-S5. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/20621240

Mercola, Dr. J. (2015). Thyme oil: A natural antibiotic. Retrieved July 1, 2015, from http://articles.mercola.com/herbal-oils/thyme-oil.aspx

Our Herb Garden. (2015). Thyme history – Name origins. Retrieved July 1, 2015, from http://www.ourherbgarden.com/herb-history/thyme.html

Rehman, A-u-, Mannan, A., Inayatullah, S. Akhtar, M. Z., Qayyum, M., & Mirza, B. (2009). Biological evaluation of wild thyme (Thymus serpyllum). Pharmaceutical Biology, 47(7), 628-633. doi: 10.1080/13880200902915622

Sienkiewicz, M., Lysakowska, M., Denys, P., & Kowalczyk, E. (2012). The antimicrobial activity of thyme essential oil against multidrug resistant clinical bacterial strains. Microbial Drug Resistance. 18(2), 137-148. doi: 10.1089/mdr.2011.0080

Stahl-Biskup, E., & Saez, F. (2003). Thyme: The genus Thymus. Florida: Taylor & Francis. Retrieved from https://www.crcpress.com/Thyme-The-Genus-Thymus/StahlBiskup-Saez/9780415284882

Pictures

Beeyoutiful. (2015). Thyme essential oil-1 fl oz., [Photograph] Retrieved from http://www.beeyoutiful.com/thyme.html

Hajmehdipoor, H., Shekarchi, M., Khanavi, M., Abid, N., & Amri, M. (2010). Figures 0001: Structures of thymol and carvacrol [Image]. Retrieved from http://openi.nlm.nih.gov/detailedresult.php?img=2950374_PM-6-154-g001&req=4

Johnson & Johnson. (n.d.). Listerine, [Photograph]. Retrieved from http://www.kilmerhouse.com/2008/02/listerine-antiseptic-a-very-useful-product/