Oil of Wild Oregano 

By Lesley Braun B.Pharm, Dip.App.Sci.NAT, Grad Dip.Phyto, PhD

According to the Western herbal medicine tradition, oregano has been used as an expectorant and natural antibiotic to treat cough and as a digestive stimulant to alleviate dyspepsia and increase appetite. Its antibacterial properties have also been used to treat skin and gastrointestinal infections. Additionally, it has been used for menstrual conditions such as period pain.

Like all herbs, oregano has several other names. It is also known as origanum, mountain mint, wild or winter marjoram, wintersweet and carvacrol

More recently, the essential oil of wild oregano has become popular and found to contain many active ingredients. One of the most important is carvacrol. Carvacrol-containing essential oils such as oregano are biostatic or biocidal against many bacteria, yeasts and fungi (1). This means the oils can either eradicate or stop the growth of many different micro-organisms. Thymol is the other major active ingredient in oregano oil and also has antibacterial effects.

Naturally, wild oregano oil has broad spectrum antibacterial activity, much like an antibiotic drug. This has been demonstrated in multiple test tube studies. For example, it stops the growth of the main bacteria responsible for food poisoning and travellers diarrhoea (E.coli) and a common bacteria involved in many skin infections (S.aureus) (2). It also has antifungal activity and is effective against the yeast Candida albicans which is the fungus responsible for vaginal thrush. The oil has also been used to treat intestinal parasites. This is supported by a human study which found that treatment with an emulsified form of the oil eradicated most of the infectious agents after 6 weeks (3).

New research suggests that wild oregano oil may play a future role in treating some antibiotic resistant infections such as methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE). Both of these strains have been observed worldwide in extensive hospital outbreaks and are presenting doctors with huge challenges. According to test tube studies, topically applied oregano oil has antibacterial effects against both MRS strains (4). Now what’s required is human research to determine just how good the oil is in clinical practice.

Due to its many different effects, wild oregano oil has many varied uses. It has been used orally for respiratory infections such as sinusitis and the common cold, allergies, ear infections and arthritis. Sometimes it is applied topically to treat conditions such as acne, athlete’s foot, dandruff and insect bites. Oregano oil has been used as an insect repellent against biting midges which are sometimes called no-see-ums (Culicodoides imicola). To date, there have been relatively few human studies to confirm these benefits and further research is urgently required. 

Besides acting as a natural antibiotic, antifungal and antiparasitic medicine, wild oregano oil has antioxidant properties (5). This is due to key ingredients carvacrol and thymol working together with other natural ingredients found in the oil. The antioxidant effect provides an explanation as to why the ancients found oregano such an effective food preservative. Interestingly, it’s still used for this purpose by the food industry today. 

In the United States, oregano oil is Generally Recognised as Safe (GRAS). Despite this, it is not recommended in pregnancy. In some cases it can also cause possible side effects such as gastrointestinal discomfort and loose bowels when taken orally. People who are allergic to the Lamiaceae family of plants should avoid use of this substance. Finally, if you are going to use oregano oil on the skin, it’s a good idea to apply it to a small area first and wait and see whether it causes an irritation before applying it to larger areas of the skin.  

By Lesley Braun B.Pharm, Dip.App.Sci.NAT, Grad Dip.Phytotherapy, PhD

Reference List

   (1)    Dusan F, Marian S, Katarina D, Dobroslava B. Essential oils--their antimicrobial activity against Escherichia coli and effect on intestinal cell viability. Toxicology in Vitro 2006; 20(8):1435-1445.

   (2)    Baydar H, Sagdic O, Ozkan G, Karadogan T. Antibacterial activity and composition of essential oils from Origanum, Thymbra and Satureja species with commercial importance in Turkey. Food Control 2004; 15(3):169-172.

   (3)    Force M, Sparks WS, Ronzio RA. Inhibition of enteric parasites by emulsified oil of oregano in vivo. Phytother Res 2000; 14(3):213-214.

   (4)    Nostro A, Blanco AR, Cannatelli MA, Enea V, Flamini G, Morelli I et al. Susceptibility of methicillin-resistant staphylococci to oregano essential oil, carvacrol and thymol. FEMS Microbiology Letters 2004; 230(2):191-195.

   (5)    Kulisic T, Radonic A, Katalinic V, Milos M. Use of different methods for testing antioxidative activity of oregano essential oil. Food Chemistry 2004; 85(4):633-640.