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Oil of Oregano - Bearer of Many Excellent Clinical Properties

07/01/2017 - Product Newsletter #303

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While there is certainly no shortage of controversies today concerning our various approaches to patient care from a functional medicine/clinical nutrition standpoint, I would guess with great confidence that there is one issue about which we can all agree.  The need to optimize GI health and function is a virtually universal need in all chronically ill patients whether or not the chief complaints specifically involve the gastrointestinal tract.  Therefore, we at Moss Nutrition have, from our inception, made it a priority to provide you with a menu of several products from which you can chose to address the unique GI support needs that each chronically ill patient almost invariably presents. 

Of course, as more and more studies continually make clear, disturbances in gut microflora, ranging from imbalances in resident organisms to the presence of pathogenic organisms to overgrowth in the small intestine (SIBO), are at the foundational heart of most GI-related chief complaints and many of the non GI-related chief complaints.  Therefore, because different products are needed for different presentations of aberrant microfloral populations, we have done our best to offer an array of products that can assist you in your efforts to optimize the gut microbiome. 

One of those products that has withstood the test of time in terms of predictable efficacy is oil of oregano.  Therefore, in this month's product newsletter I would like to feature our Oil of Oregano product, highlighting some of the published research that documents its outstanding clinical utility.  The first paper I would like to feature, "Oregano essential oil as an antimicrobial and antioxidant additive in food products" by Rodriguez-Garcia et al (Rodriguez-Garcia I et al, Crit Rev Food Sci Nutr, Vol. 56, pp. 1717-1727, 2016) provides a general overview of the properties of oil of oregano.  Before beginning my review of this paper, though, please note again its title.  Even though we generally regard and use oil of oregano as an antimicrobial, it can also act as a very useful and powerful antioxidant.  Therefore, in the course of this review I will be featuring both the antimicrobial and antioxidant properties of this substance.

The first quote from this paper I would like to highlight makes clear the dual functions of oil of oregano:

"Oregano essential oil (OEO) has been found to be amongst the most effective antimicrobial and antioxidant natural agents.  In view of the published data on the antimicrobial efficacy of essential oil (EO), the following general ranking (in order of decreasing antibacterial activity) can be made: oregano/clove/cordiander/cinnamon>thyme> mint>rosemary>mustard>cilantro/sage."

Next, it should be noted that there are different types of oregano:

"There are different types of oregano from the genus Origanum: O. vulgare L, O. viride, and O. virens representing the Mediterranean region."

O. vulgare L is what is found in the Moss Nutrition Oil of Oregano product.  What are the active ingredients in oil of oregano and what are the properties of these ingredients?  Rodriguez-Garcia et al state:

"Carvacrol and thymol are the main antimicrobial and antioxidant monoterpene phenolic compounds that constitute about 78-85% of OEO.  The antimicrobial activity of these compounds is attributed to their lipophilic character that makes them more attractive to the cell membrane structures.  Consequently, their presence cause membrane expansion, increases fluidity and permeability, disturbs embedded proteins, inhibits respiration, and alters ion transport processes.  These compounds act as antioxidant agents quenching free radicals by donating hydrogen atoms or electrons, retarding lipid oxidation.  In addition, to the antimicrobial and antioxidant properties of OEO, carvacrol and thymol provide the characteristic flavor and odor."

What can specifically be stated about the antioxidant properties of OEO?  The authors note:

"The antioxidant effect of OEO is attributed to their major components, carvacrol and thymol, and it is the result of various possible mechanisms: free-radical scavenging activity, transition-metal-chelating activity, and/or singlet-oxygen-quenching capacity.  Carvacrol and thymol can donate hydrogen atoms to free radicals and convert them to more stable nonradical products."

What about the antimicrobial properties?  Rodriguez-Garcia et al point out:

"Carvacrol and thymol are the major antimicrobial compounds found in different OEO.  It has been found that these agents cause alterations in the fungi hyphal morphology and aggregates, resulting in reduced diameters and lyses."


"In bacteria, the cell membrane is a very important target to the OEO components like terpenoids that could interfere with the phospholipid bilayers membrane.  Thymol and carvacrol are able to disintegrate the outer membrane of the gram negative bacteria, releasing the lipopolysaccharide components, and thus increasing the permeability of the adenosine triphosphate in the cytoplasmic membrane, and consequently changing the passive permeability of the cell."

Before leaving this paper I would like to highlight two more key quotes.  The first makes it clear that, as you have probably seen clinically, oil of oregano works best when used with other antimicrobial and antioxidant supplements:

"This review found that OEO possesses high antimicrobial and antioxidant properties compared to other natural sources, in addition, when combined with other species may have a synergistic effect."

The second quote makes it clear that, while oil of oregano is an excellent antibacterial agent, it is exceptionally effective with fungal forms:

"This oil is generally more active against fungi than bacteria and more effective against Gram-positive than Gram-negative bacteria."

The last three papers I would like to review in relation to oil of oregano discuss specific clinical applications.  The first two discuss the impact of oil of oregano on candida.  In "In vitro activity of Origanum vulgare essential oil against candida species" by Cleff et al (Cleff MB et al.  Brazilian J Microbiol, Vol. 41, pp. 116-123, 2010) the following is concluded:

"Based on the results presented herein, it is possible to conclude that the essential oil extracted from O. vulgare may represent a good alternative for the treatment of candidiasis due to its appreciable antifungal action against Candida spp in vitro."

The paper "Antifungal activities of origanum oil against Candida albicans" by Manohar et al (Manohar V et al.  Molecular Cellular Biochem, Vol. 228, pp. 111-117, 2001) provides much more detail on the antifungal properties of oil of oregano.  The first quote I would like to feature from this paper provides an overview of the authors' findings:

"We have demonstrated that origanum oil inhibits the growth of C. albicans in vitro as well as in vivo.  We conclude that the daily oral administration of origanum oil may be highly effective in the prevention and treatment of candidiasis."

The next quote provides more detail on the impact of oil of oregano on various fungal forms besides candida:

"Origanum oil has been shown to delay or inhibit the growth of saprophytic food spoiling fungi such as Aspergillus flavus (mycotoxogenic) and industrial yeasts such as Hansenula anoma.  Furthermore, origanum oil, and carvacrol have been reported to have some promising effect on rats infected with a human dermatophytic fungus, Trichophyton rubrum."

The next quote provides more detail on the impact of oil of oregano on candida:

"In this paper we have demonstrated that origanum oil effectively inhibits the in vitro growth of C. albicans, a human yeast-like fungus which can cause both systemic and superficial infections in debilitated individuals.  In addition we have shown that origanum oil directly inhibits germination and filament formation (the two phases required for tissue invasion) by C. albicans."

Manohar et al next comment on some of the other physiologic properties of oil of oregano:

"It has been demonstrated that some of these components of origanum oil have antispasmodic and antioxidant potentials."

The authors conclude their paper by stating the following:

"In summary, the results presented in this paper conclusively demonstrate the antifungal potential of edible origanum oil.  Origanum oil is shown to be both fungistatic and fungicidal to C. albicans, the human pathogenic yeast.  Both the germination and the pseudomycelial phase of the yeast are inhibited in vitro.  Further, the daily oral administration of as little as 1.0 l of oil for 30 days completely freed 80% of the laboratory mice from experimental systemic candidiasis, which is fatal if not treated.  Thus, daily oral administration of origanum oil may be highly effective in the prevention of and treatment of candidiasis."

The last paper I would like to highlight evaluates the use of oil of oregano for a specific clinical application, management of vaginal infections.  In "Origanum vulgare essential oil affects pathogens causing vaginal infections" by Karaman et al (Karaman M et al.  J Applied Microbiol, Vol. 122, pp. 1177-1185, 2017) the following is concluded:

"Based on the presented results, the essential oil of O. vulgare could be used in a treatment of gynaecological infections caused by some strains of E. coli, S. aureus, P. mirabilis and C. albicans.  Since the use of plant-derived compounds in the treatment of genital infections represents an additional therapy on the increase, the possible use of this essential oil in routine gynaecological use could be aimed at incorporation of main constituents of oregano oil as an integral part of the following traditional herbal medicinal products such as vaginalettes and vaginal tablets, vaginal creams, a vaginal douche or applied essential oil dilution to the tampon for a shorter period of time."

As many of you know, oil of oregano has been around for many years and, sometimes, along with familiarity comes lack of attention.  It is my hope that this review of the literature on the many excellent clinical properties of oil of oregano which include, but are not limited to, outstanding, broad-spectrum antimicrobial effects, will act to jog your memory to think of oil of oregano whenever you feel your patient would benefit from antimicrobial supplementation. 

Oil of Oregano from Moss Nutrition is available in 2 sizes: 60 Softgels and 120 Softgels. 
Each Softgel supplies 150 mg of Oil of Oregano Extract (55% carvacrol).