In a ground-breaking study published in 2015 researchers showed that the essential oils in oregano oil (i.e., carvacrol) showed the strongest bacteria-killing (anti-microbial) effect against 32 erythromycin-resistant bacteria, including Group A streptococcus resistant bacteria, when compared to antimicrobial essential oils from thyme, lavender, peppermint, and tea tree oil. In fact, the study showed that carvacrol from oregano oil acts either alone or in combination with erythromycin against
erythromycin-resistant Group A streptococcus bacteria.

Oregano oil contains two phenolic monoterpenes (carvacrol and thymol), which damage the membrane of many pathogenic bacteria, literally killing them on contact. Scientists are now looking at using oregano oil concentrates and extracts as antimicrobial agents to fight antibiotic-resistant bacteria and/or to combine oregano supplements with existing antibiotics.

Reference: Frontiers of Microbiology 2015.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4347498/#:~:text=The%20antibacterial%20action%20of%20carvacrol,other%20energy%2Ddependent%20cell%20processes%2C

Carvacrol and thymol are the two novel phenols that constitute 78-85% of oregano’s essential oils and are the principal medicinal agents responsible for its known antimicrobial activity. These medicinal agents show antimicrobial effects against pathogenic bacteria, viruses, and fungi, including Candida albicans.

As stated in the 2018 study (see below), oregano’s antifungal actions have been found to be similar to nystatin and amphotericin B, when studied in animals and humans. The 2021 study listed below highlights the antimicrobial effect of oregano oil against many pathogenic gram-positive and gram-negative bacteria.

References: J Molecules 2017.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6152729/

J Contemporary Clinical Dentistry 2018.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6006875/

J Molecules 2021.
https://www.mdpi.com/1420-3049/26/22/7017

Our (Adeeva) introduction to the clinical use of oregano oil came from Dr. Cass Ingram, who initiated the first antimicrobial testing of the P73 wild oregano species in studies at Georgetown University dating back to 2001: (https://pubmed.ncbi.nlm.nih.gov/11855736/).

This study and others that followed showed that essential oils from the P73 Wild Oregano species exhibit potent killing effects against many pathogenic bacteria, fungi and viruses: (https://www.sbmicrobiologia.org.br/cd28cbm/resumos/R0815-2.PDF; https://www.sciencedaily.com/releases/2001/10/011011065609.htm ).

These studies prompted us (Adeeva) to private label the potent P73 Wild Oregano Extract into Adeeva Orega-Sept Capsules, which many of us use to help fight off typical colds and flus during flu season.

At the first sign of a cold or flu, many of us take 4 capsules of Adeeva Orega-Sept, three times daily to help fight off the invading microbe. In combination with other strategies (increasing vitamin C intake, etc.) many of us have discovered the value of Orega-Sept Capsules for this purpose.

It is important not to use Orega-Sept Capsules in place of prescribed antibiotic drugs, but studies show that oregano oil and its potent extracts can be used in combination with antibiotic drugs.

Note also, that when taking Adeeva Orega-Sept Capsules, you should also take a probiotic supplement to prevent the overkilling of your gut microflora by carvacrol and thymol.

To learn more about Adeeva Orega-Sept Capsules click on this link:
https://adeeva.com/product/orega-sept-capsules/

The research on the anti-microbial effects of oregano’s essential oils has been unfolding in peer-review published studies since the year 1999. A chronological overview of this research can be found by reading these additional research papers:

1. Ultee, A.; Kets, E.P.W.; Smid, E.J. Mechanisms of Action of Carvacrol on the Food-Borne Pathogen Bacillus cereus. Appl. Environ. Microbiol. 1999, 65, 4606–4610.
2. Monhar V et al. Anti-fungal activities or origanum oil against Candida albicans. Molecular and Cellular Biochemisty. 2001, 228: 111-117.
3. Lambert, R.; Skandamis, P.; Coote, P.; Nychas, G.-J. A study of the minimum inhibitory concentration and mode of action of oregano essential oil, thymol and carvacrol. J. Appl. Microbiol. 2001, 91, 453–462.
4. Si, H.; Hu, J.; Liu, Z.; Zeng, Z.-L. Antibacterial effect of oregano essential oil alone and in combination with antibiotics against extended-spectrum β-lactamase-producing Escherichia coli. FEMS Immunol. Med. Microbiol. 2008, 53, 190–194.
5. Nostro, A.; Papalia, T. Antimicrobial Activity of Carvacrol: Current Progress and Future Prospectives. Recent Pat. Anti-Infect. Drug Discov. 2012, 7, 28–35.
6. Cattelan, M.G.; Castilhos, M.; Sales, P.J.P.; Hoffmann, F.L. Antibacterial activity of oregano essential oil against foodborne pathogens. Nutr. Food Sci. 2013, 43, 169–174.
7. Boskovic, M.; Zdravkovic, N.; Ivanovic, J.; Janjic, J.; Djordjevic, J.; Starcevic, M.; Baltic, M.Z. Antimicrobial Activity of Thyme (Tymus vulgaris) and Oregano (Origanum vulgare) Essential Oils against Some Food-borne Microorganisms. Procedia Food Sci. 2015, 5, 18–21.
8. Pesavento, G.; Calonico, C.; Bilia, A.; Barnabei, M.; Calesini, F.; Addona, R.; Mencarelli, L.; Carmagnini, L.; Di Martino, M.; Nostro, A.L. Antibacterial activity of Oregano, Rosmarinus and Thymus essential oils against Staphylococcus aureus and Listeria monocytogenes in beef meatballs. Food Control. 2015, 54, 188–199.
9. Coccimiglio, J.; Alipour, M.; Jiang, Z.-H.; Gottardo, C.; Suntres, Z. Antioxidant, Antibacterial, and Cytotoxic Activities of the Ethanolic Origanum vulgare Extract and Its Major Constituents. Oxidative Med. Cell. Longev. 2016, 2016, 1404505.
10. Hercules, S. Antimicrobial Activity of Basil, Oregano, and Thyme Essential Oils. J. Microbiol. Biotechnol. 2016, 27, 429–438.
11. Lu, M.; Dai, T.; Murray, C.K.; Wu, M.X. Bactericidal Property of Oregano Oil Against Multidrug-Resistant Clinical Isolates. Front. Microbiol. 2018, 9, 2329.
12. Taleb, M.H.; Abdeltawab, N.F.; Shamma, R.N.; Abdelgayed, S.S.; Mohamed, S.S.; Farag, M.A.; Ramadan, M.A. Origanum vulgare L. Essential Oil as a Potential Anti- Acne Topical Nanoemulsion-In Vitro and In Vivo Study. Molecules 2018, 23, 2164.
13. Abouelezz, K.; Abou-Hadied, M.; Yuan, J.; Elokil, A.A.; Wang, G.; Wang, S.; Wang, J.; Bian, G. Nutritional impacts of dietary oregano and Enviva essential oils on the performance, gut microbiota and blood biochemicals of growing ducks. Animal 2019, 13, 2216–2222.
14. Man, A.; Santacroce, L.; Jacob, R.; Mare, A.; Man, L. Antimicrobial Activity of Six Essential Oils against a Group of Human Pathogens: A Comparative Study. Pathogens 2019, 8, 15.
15. Sim, J.X.F.; Khazandi, M.; Chan, W.Y.; Trott, D.J.; Deo, P. Antimicrobial activity of thyme oil, oregano oil, thymol and carvacrol against sensitive and resistant microbial isolates from dogs with otitis externa. Veter Dermatol. 2019, 30, 524-e159.
16. Boskovic, M.; Djordjevic, J.; Glisic, M.; Ciric, J.; Janjic, J.; Zdravkovic, N.; Krnjaic, D.; Baltic, M.Z. The effect of oregano (Origanum vulgare) essential oil on four Salmonella serovars and shelf life of refrigerated pork meat packaged under vacuum and modified atmosphere. J. Food Process. Preserv. 2019, 44, e14311.
17. Garcia-Galicia, I.A.; Arras-Acosta, J.A.; Huerta-Jimenez, M.; Rentería-Monterrubio, A.L.; Loya-Olguin, J.L.; Carrillo-Lopez, L.M.; Tirado-Gallegos, J.M.; Alarcon-Rojo, A.D. Natural Oregano Essential Oil may Replace Antibiotics in Lamb Diets: Effects on Meat Quality. Antibiotics 2020, 9, 248.
18. Ignatova-Ivanova, T.; Yotova, I.; Ivanov, R. In vitro study of biological activity essential oil of Origanum vulgare L. subsp. vulgare L. J. Chem. Pharm. Res. 2016, 8, 958–962.
19. Liu, Q.; Meng, X.; Li, Y.; Zhao, C.-N.; Tang, G.-Y.; Li, H.- B. Antibacterial and Antifungal Activities of Spices. Int. J. Mol. Sci. 2017, 18, 1283.
20. Sobczyk, A.D.E.; Luchese, C.L.; Faccin, D.J.L.; Tessaro, I.C. Influence of replacing oregano essential oil by ground oregano leaves on chitosan/alginate-based dressings properties. Int. J. Biol. Macromol. 2021, 181, 51–59.