Oregano (Origanum vulgare) Research

Latin Name: Origanum vulgare

Family: Lamiaceae

Oregano has strong antimicrobial activities and has shown action against a variety of bacteria, fungi, and viruses.  It has also shown potential as an insecticidal, repellent, and against parasites.  In vitro studies have shown anti-cancer and antioxidant actions.  The herb may also be helpful in reducing blood sugar and cholesterol levels.

RESEARCH

The listings of research below represents a compilation of scientific articles found on the species, with a very brief overview description of each article/study.  Research found is catalogued by therapeutic action.  This categorized compilation of research articles does not necessarily imply that there are adequate results to demonstrate safe and/or effective human use.

GENERAL

• This is a summary of research on therapeutic actions of carvacrol, including: antimicrobial, antitumor, antimutagenic, antigenotoxic, analgesic, antispasmodic, anti-inflammatory, angiogenic, antiparasitic, antiplatelet, Ache inhibitory, anti-elastase, insecticidal, antihepatotoxic and hepatoprotective activities and uses such as feed additive, in honeybee breeding and in gastrointestinal ailments. From:  Can Baser, K. H. (2008). Biological and pharmacological activities of carvacrol and carvacrol bearing essential oils. Current pharmaceutical design, 14(29), 3106-3119.
• Various actions of oregano were analyzed in vitro.  From:  Babili, F. E., Bouajila, J., Souchard, J. P., Bertrand, C., Bellvert, F., Fouraste, I., … & Valentin, A. (2011). Oregano: chemical analysis and evaluation of its antimalarial, antioxidant, and cytotoxic activities. Journal of food science, 76(3), C512-C518.
• Lis-Balchin, M. (2006). Aromatherapy Science: A guide for healthcare professionals. London: Pharmaceutical Press.
• Petersen, D. (2015). Aromatherapy materia medica.  Essential oil monographs.  American College of Healthcare Sciences.
• Tisserand, R. & Young, R. (2014).  Essential Oil Safety.  Second Edition.  Churchill, Livingstone, Elsevier.
• WebMD. (n.d.).  Oregano.  Retrieved in March, 2016.  Retrieved from www.webmd.com
• Luteolin is a flavonoid found in carrots, peppers, celery, olive oil, peppermint, thyme, rosemary and oregano. This study reviews its antioxidant, anti-inflammatory, antimicrobial and anticancer activities. From:  López-Lázaro, M. (2009). Distribution and biological activities of the flavonoid luteolin. Mini reviews in medicinal chemistry, 9(1), 31-59.

SAFETY / QUALITY

• Carvacrol and thymol constituents of essential oil are possible mucous membrane and skin irritants.
• Not for those with asthma or liver disease (Petersen, 2015).
• Can be toxic to the liver in excess.  Do not use essential oil in large doses (more than a few drops a day for adults) or beyond two weeks.
• Not for use beyond food amounts during pregnancy, during breastfeeding; or with young children, can cause embryotoxicity (Tisserand & Young, 2014).
• May increase bleeding in those with bleeding disorders, or up to two weeks before surgery (WebMD, n.d.).
• Might lower blood sugar levels in those with diabetes (WebMD, n.d.).
• May interfere with the drug, Lithium (WebM.D, n.d.).

ANTIMICROBIAL / ANTIBACTERIAL / ANTIFUNGAL / ANTIVIRAL

• The use of plant essential oils against antibiotic resistant microbes is discussed. Key essential oils include basil, cilantro, coriander, cinnamon, clove, curry, garlic, helichrysum, lavender, lemongrass, oregano, peppermint, and tea tree. From: Yang, S. K., Low, L. Y., Yap, P. S. X., Yusoff, K., Mai, C. W., Lai, K. S., & Lim, S. H. E. (2018). Plant-Derived Antimicrobials: Insights into Mitigation of Antimicrobial Resistance. Records of Natural Products, 12(4).
• Essential oils from anise, angelica, basil, carrot, celery, cardamom, coriander, dill weed, fennel, oregano, parsley, and rosemary were evaluated for antimicrobial activity.  Oregano, basil, and coriander showed the highest activity.  From:  Elgayyar, M., Draughon, F. A., Golden, D. A., & Mount, J. R. (2001). Antimicrobial activity of essential oils from plants against selected pathogenic and saprophytic microorganisms. Journal of Food Protection®, 64(7), 1019-1024.
• Twenty-five bacteria species and one fungal species were tested against laurel, sage, rosemary, oregano, and coriander and the oils showed a high degree of inhibition against them all, with the oregano being the strongest.  From:  Baratta, M. T., Dorman, H. D., Deans, S. G., Biondi, D. M., & Ruberto, G. (1998). Chemical composition, antimicrobial and antioxidative activity of laurel, sage, rosemary, oregano and coriander essential oils. Journal of Essential Oil Research, 10(6), 618-627.
• Penicillium digitatum fungus was inhibited completely by oregano, thyme, dictamus, and marjoram essential oils at low concentrations. From:  Daferera, D. J., Ziogas, B. N., & Polissiou, M. G. (2000). GC-MS analysis of essential oils from some Greek aromatic plants and their fungitoxicity on Penicillium digitatum. Journal of Agricultural and Food Chemistry, 48(6), 2576-2581.
• Oregano, spearmint, lavender, and sage essential oils and the constituents of carvacrol and thymol exhibited antifungal properties against the human pathogens Malassezia furfur, Trichophyton rubrum, and Trichosporon beigelii. From:  Adam, K., Sivropoulou, A., Kokkini, S., Lanaras, T., & Arsenakis, M. (1998). Antifungal activities of Origanum vulgare subsp. hirtum, Mentha spicata, Lavandula angustifolia, and Salvia fruticosa essential oils against human pathogenic fungi. Journal of Agricultural and Food Chemistry, 46(5), 1739-1745.
• Satureja hortensis and Origanum vulgare, and their carvacrol constituent were antibacterial against Helicobacter pylori in vitro.  From:  Lesjak, M., Simin, N., Orcic, D., Franciskovic, M., Knezevic, P., Beara, I., … & Mimica‐Dukic, N. (2016). Binary and tertiary mixtures of Satureja hortensis and Origanum vulgare essential oils as potent antimicrobial agents against Helicobacter pylori. Phytotherapy research, 30(3), 476-484.
• Roman chamomile, curry plant, hyssop, lavandin, marjoram sweet, orange mint, spearmint, monarda, oregano, rosemary, rue sage, tansy, tarragon, thyme common and yarrow showed vapour activity against the fungi that causes ringworm. From:  Inouye, S., Uchida, K., & Abe, S. (2006). Volatile composition and vapour activity against Trichophyton mentagrophytes of 36 aromatic herbs cultivated in Chichibu district in Japan. International Journal of Aromatherapy, 16(3), 159-168.
• Cinnamon, Mexican oregano, oregano, thyme, and ginger essential oils showed antifungal activity.  From:  Pozzatti, P., Scheid, L. A., Spader, T. B., Atayde, M. L., Santurio, J. M., & Alves, S. H. (2008). In vitro activity of essential oils extracted from plants used as spices against fluconazole-resistant and fluconazole-susceptible Candida spp. Canadian journal of microbiology, 54(11), 950-956.
• Essential oils of cinnamon, peppermint, basil, origanum, clove, and thyme caused a total inhibition of fungal development on maize kernels without a phytotoxic effect.  From:  Montes-Belmont, R., & Carvajal, M. (1998). Control of Aspergillus flavus in maize with plant essential oils and their components. Journal of Food Protection®, 61(5), 616-619.
• Oregano was effective against Staphylococcus aureus.  From:  de Souza, E. L., de Barros, J. C., de Oliveira, C. E. V., & da Conceição, M. L. (2010). Influence of Origanum vulgare L. essential oil on enterotoxin production, membrane permeability and surface characteristics of Staphylococcus aureus. International journal of food microbiology, 137(2), 308-311.
• Cinnamon, thyme, oregano, and cumin stopped mycelial growth at the lowest concentration. From:  Tantaoui-Elaraki, A., & Beraoud, L. (1993). Inhibition of growth and aflatoxin production in Aspergillus parasiticus by essential oils of selected plant materials. Journal of environmental pathology, toxicology and oncology: official organ of the International Society for Environmental Toxicology and Cancer, 13(1), 67-72.
• Oregano, thyme, cinnamon bark, lemongrass, clove, palmarose, peppermint, lavender,  geranium Bourbon, and tea tree reduced fungus in heated footbath water.  From:  Inouye, S., Uchida, K., Nishiyama, Y., Hasumi, Y., Yamaguchi, H., & Abe, S. (2007). Combined effect of heat, essential oils and salt on the fungicidal activity against Trichophyton mentagrophytes in foot bath. Nippon Ishinkin Gakkai Zasshi, 48(1), 27-36.
• Oregano (Origanum syriacum), thyme (Thymbra spicata), lavender (Lavandula stoechas), rosemary (Rosmarinus officinalis), fennel (Foeniculum vulgare), and laurel (Laurus nobilis), inhibited growth of tomatoe fungus.  From:  Soylu, E. M., Soylu, S., & Kurt, S. (2006). Antimicrobial activities of the essential oils of various plants against tomato late blight disease agent Phytophthora infestans. Mycopathologia, 161(2), 119-128.
• Allspice, garlic, and oregano oils added to tomato sauce, were antimicrobial.  From:  Du, W. X., Olsen, C. W., Avena‐Bustillos, R. J., McHugh, T. H., Levin, C. E., Mandrell, R., & Friedman, M. (2009). Antibacterial Effects of Allspice, Garlic, and Oregano Essential Oils in Tomato Films Determined by Overlay and Vapor‐Phase Methods. Journal of Food Science, 74(7), M390-M397.
• Oregano, coriander, and basil essential oil showed the greatest inhibition to the other bacteria and fungi tested. Anise oil was not particularly inhibitory to bacteria but was highly inhibitory to molds. From:  Elgayyar, M., Draughon, F. A., Golden, D. A., & Mount, J. R. (2001). Antimicrobial activity of essential oils from plants against selected pathogenic and saprophytic microorganisms. Journal of Food Protection®, 64(7), 1019-1024.
• Oregano and thyme oils showed strong antibacterial activity. From:  De Martino, L., De Feo, V., & Nazzaro, F. (2009). Chemical composition and in vitro antimicrobial and mutagenic activities of seven Lamiaceae essential oils. Molecules, 14(10), 4213-4230.
• Oregano and thyme EO possess significant in vitro antimicrobial properties and oregano irreversibly damaged E. coli cells within one minute. From:  Burt, S. A., & Reinders, R. D. (2003). Antibacterial activity of selected plant essential oils against Escherichia coli O157: H7. Letters in applied microbiology, 36(3), 162-167.
• Oregano and mint were antifungal against Aspergillus ochraceus.  From:  Basilico, M. Z., & Basilico, J. C. (1999). Inhibitory effects of some spice essential oils on Aspergillus ochraceus NRRL 3174 growth and ochratoxin A production. Letters in Applied Microbiology, 29(4), 238-241.
• Oregano, and constituents thymol and carvacrol were antifungal in vitro.  From:  Akgül, A., & Kivanc, M. (1988). Inhibitory effects of selected Turkish spices and oregano components on some foodborne fungi. International Journal of Food Microbiology, 6(3), 263-268.
• Origanum vulgare, Thymus zygis, and Thymus mastichina showed high antimicrobial activity against four strains of Salmonella.  From:  Penalver, P., Huerta, B., Borge, C., Astorga, R., Romero, R., & Perea, A. (2005). Antimicrobial activity of five essential oils against origin strains of the Enterobacteriaceae family. Apmis, 113(1), 1-6.
• Lemon balm, marjoram, oregano and thyme essential oils showed antimicrobial activity against food spoilage bacteria.  From:  Gutierrez, J., Barry-Ryan, C., & Bourke, P. (2009). Antimicrobial activity of plant essential oils using food model media: efficacy, synergistic potential and interactions with food components. Food microbiology, 26(2), 142-150.
• From 22 essential oils tested, cornmint, cumin, laurel, lemon peel, orange, oregano, and Ziziphora were active against all assessed bacteria. From:  Kivanç, M., & Akgül, A. (1986). Antibacterial activities of essential oils from Turkish spices and citrus. Flavour and Fragrance Journal, 1(4‐5), 175-179.
• Origanum oil was effective against systemic and superficial fungal infections in mice and could be useful in pathogenic manifestations including malignancy.  From:  Manohar, V., Ingram, C., Gray, J., Talpur, N. A., Echard, B. W., Bagchi, D., & Preuss, H. G. (2001). Antifungal activities of origanum oil against Candida albicans. Molecular and cellular biochemistry, 228(1-2), 111-117.
• 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
• Oregano extract was antibacterial against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Helicobacter pylori, and Mycobacterium terrae.   From:  Preuss, H. G., Echard, B., Enig, M., Brook, I., & Elliott, T. B. (2005). Minimum inhibitory concentrations of herbal essential oils and monolaurin for gram-positive and gram-negative bacteria. Molecular and cellular biochemistry, 272(1-2), 29-34.
• Oregano and its thymol and carvacrol constituents were effective against methicillin-resistant staphylococci (MSS, MRS).  From:  Nostro, A., Blanco, A. R., Cannatelli, M. A., Enea, V., Flamini, G., Morelli, I., … & Alonzo, V. (2004). Susceptibility of methicillin-resistant staphylococci to oregano essential oil, carvacrol and thymol. FEMS Microbiology Letters, 230(2), 191-195.
• Carvacrol and thymol, as found in oregano, can be used to treat food spoilage pathogens.  From:  Lambert, R. J. W., Skandamis, P. N., Coote, P. J., & Nychas, G. J. (2001). A study of the minimum inhibitory concentration and mode of action of oregano essential oil, thymol and carvacrol. Journal of applied microbiology, 91(3), 453-462.
• Essential oils from Origanum officinalis and Cymbopogon citratus were highly active against ten bacteria species.  From:  Deans, S. G., Svoboda, K. P., Gundidza, M., & Brechany, E. Y. (1990, September). Essential oil profiles of several temperate and tropical aromatic plants: their antimicrobial and antioxidant activities. In International Symposium on Medicinal and Aromatic Plants, XXIII IHC 306 (pp. 229-232).
• Oregano, basil, and thyme exhibited antioxidant, antibacterial, and antifungal activity.  Oregano was effective against multiresistant strains of Pseudomonas aeruginosa and Escherichia coli.  From:  Bozin, B., Mimica-Dukic, N., Simin, N., & Anackov, G. (2006). Characterization of the volatile composition of essential oils of some Lamiaceae spices and the antimicrobial and antioxidant activities of the entire oils. Journal of agricultural and food chemistry, 54(5), 1822-1828.
• Oregano essential oil was antimicrobial against P. aeruginosa and S. aureus.  From:  Bouhdid, S., Abrini, J., Zhiri, A., Espuny, M. J., & Manresa, A. (2009). Investigation of functional and morphological changes in Pseudomonas aeruginosa and Staphylococcus aureus cells induced by Origanum compactum essential oil. Journal of applied microbiology, 106(5), 1558-1568.
• Origanum onites, Mentha piperita, Juniperus exalsa, Chrysanthemum indicum, Lavandula hybrida, Rosa damascena, Echinophora tenuifolia, and Foeniculum vulgare were tested for antimicrobial activity. From:  Andoğan, B. C., Baydar, H., Kaya, S., Demirci, M., Özbaşar, D., & Mumcu, E. (2002). Antimicrobial activity and chemical composition of some essential oils. Archives of pharmacal research, 25(6), 860-864
• Sixty-five bacteria were tested against 13 essential oils.  Cinnamon bark, cinnamon leaf, oregano, thyme, ajowan, and clove showed strong antibacterial activity.  From:  Mayaud, L., Carricajo, A., Zhiri, A., & Aubert, G. (2008). Comparison of bacteriostatic and bactericidal activity of 13 essential oils against strains with varying sensitivity to antibiotics. Letters in applied microbiology, 47(3), 167-173.
• Origanum acutidens showed broad-spectrum activity against both Gram-positive and Gram-negative bacteria.  From:  Cosge, B., Turker, A., Ipek, A., & Gurbuz, B. (2009). Chemical compositions and antibacterial activities of the essential oils from aerial parts and corollas of Origanum acutidens (Hand.-Mazz.) Ietswaart, an endemic species to Turkey. Molecules, 14(5), 1702-1712.
• Thymol and carvacrol of Thymus glandulosus and Origanum compactum exhibited the strongest antifungal activity.  From:  Bouchra, C., Achouri, M., Hassani, L. I., & Hmamouchi, M. (2003). Chemical composition and antifungal activity of essential oils of seven Moroccan Labiatae against Botrytis cinerea Pers: Fr. Journal of ethnopharmacology, 89(1), 165-169.
• Oregano and manuka essential oils were antibacterial against 14 tested strains of S. aureus.  From:  Fratini, F., Mancini, S., Turchi, B., Friscia, E., Pistelli, L., Giusti, G., & Cerri, D. (2017). A novel interpretation of the Fractional Inhibitory Concentration Index: The case Origanum vulgare L. and Leptospermum scoparium JR et G. Forst essential oils against Staphylococcus aureus strains. Microbiological research, 195, 11-17.
• Thyme, origanum, clove, and orange essential oils were the most inhibitory against foodborne bacteria and yeasts. Cumin, tea tree, and mint also provided inhibition.  From:  Irkin, R., & Korukluoglu, M. (2009). Growth inhibition of pathogenic bacteria and some yeasts by selected essential oils and survival of L. monocytogenes and C. albicans in apple–carrot juice. Foodborne pathogens and disease, 6(3), 387-394.
• Origanum compactum and O. majorana were inhibitory to a variety of yeast, mold, and bacteria species.  From:  Charai, M., Mosaddak, M., & Faid, M. (1996). Chemical composition and antimicrobial activities of two aromatic plants: Origanum majorana L. and O. compactum Benth. Journal of Essential Oil Research, 8(6), 657-664.
• Cloves, thyme, oregano, allspice, basil, rosemary, and marjoram showed antimicrobial effects on Shigella.  From:  Bagamboula, C. F., Uyttendaele, M., & Debevere, J. (2003). Antimicrobial effect of spices and herbs on Shigella sonnei and Shigella flexneri. Journal of Food Protection®, 66(4), 668-673.
• Carvacrol prevents the development of flagella in E. coli.  From:  Burt, S. A., van der Zee, R., Koets, A. P., de Graaff, A. M., van Knapen, F., Gaastra, W., … & Veldhuizen, E. J. (2007). Carvacrol induces heat shock protein 60 and inhibits synthesis of flagellin in Escherichia coli O157: H7. Applied and environmental microbiology, 73(14), 4484-4490.
• Cornmint, cumin, laurel, lemon peel, orange, oregano, and ziziphora were active against all of the tested bacteria to various degrees. From:  Kivanç, M., & Akgül, A. (1986). Antibacterial activities of essential oils from Turkish spices and citrus. Flavour and Fragrance Journal, 1(4‐5), 175-179.
• Basil, lemon balm, marjoram, oregano, rosemary, sage, and thyme showed varying degrees of antimicrobial activity on foodborne pathogens.  From:  Gutierrez, J., Rodriguez, G., Barry-Ryan, C., & Bourke, P. (2008). Efficacy of plant essential oils against foodborne pathogens and spoilage bacteria associated with ready-to-eat vegetables: antimicrobial and sensory screening. Journal of Food Protection®, 71(9), 1846-1854.
• Oregano and fennel were antifungal against the plant fungus: S. sclerotiorum.  From:  Soylu, S., Yigitbas, H., Soylu, E. M., & Kurt, Ş. (2007). Antifungal effects of essential oils from oregano and fennel on Sclerotinia sclerotiorum. Journal of applied microbiology, 103(4), 1021-1030.
• Thymus fontanessi (thyme), Origanum glandulosum (oregano), Mentha pulegium (pennyroyal),  and Lavandula stoechas (lavender) were antibacterial against Staphylococcus aureus (MRSA and MSSA). Carvacrol, thymol, pulegone, fenchone, and camphor were the strongest constituents.  From:  Bekka-Hadji, F., Bombarda, I., & Touati, A. (2016). Antibacterial activity against methicillin-resistant Staphylococcus aureus of five essential oils from Algerian medicinal plants (Lamiaceae). Journal of Essential Oil Research, 1-10.
• Varieties of oregano were antifungal in vitro.  From:  Abou-Jawdah, Y., Sobh, H., & Salameh, A. (2002). Antimycotic activities of selected plant flora, growing wild in Lebanon, against phytopathogenic fungi. Journal of agricultural and food chemistry, 50(11), 3208-3213.
• In a mega-analysis of over 500 studies on essential oil antimicrobial activity, spices and herbs of thyme, origanum, mint, cinnamon, salvia and clove had the strongest antimicrobial properties. From:  Kalemba, D., & Kunicka, A. (2003). Antibacterial and antifungal properties of essential oils. Current medicinal chemistry, 10(10), 813-829.
• Oregano’s antifungal activity against Penicillium expansum, Aspergillus flavus, Botrytis cinerea, and Colletotrichum gloeosporioides were assessed, with thymol, carvacrol, and p-cymene making it a good antifungal agent.  From:  Cid-Pérez, T. S., Torres-Muñoz, J. V., Nevárez-Moorillón, G. V., Palou, E., & López-Malo, A. (2016). Chemical characterization and antifungal activity of Poliomintha longiflora Mexican oregano. Journal of Essential Oil Research, 28(2), 157-165.
• In a study of 30 different vaginal isolated strains of C. albicans to twelve essential oils, compared to the three of the mainly used drugs (clotrimazole, fluconazole, itraconazole), mint, basil, lavender, tea tree oil, winter savory and oregano essential oils inhibited both the growth and the activity of C. albicans more efficiently than clotrimazole.  From:  Bona, E., Cantamessa, S., Pavan, M., Novello, G., Massa, N., Rocchetti, A., … & Gamalero, E. (2016). Sensitivity of Candida albicans to essential oils: are they an alternative to antifungal agents?. Journal of Applied Microbiology.
• Oils high in carvacrol content:  Oreganum onites and Satureja  thymbrra, were the most antifungal against a variety of species.  From:  Soković, M., Tzakou, O., Pitarokili, D., & Couladis, M. (2002). Antifungal activities of selected aromatic plants growing wild in Greece. Food/Nahrung, 46(5), 317-320.
• Oregano essential oil exhibited strong antimicrobial activity against 27 (77%) of the 35 bacteria, 12 (67%) of the 18 fungi, and a yeast; it also had a moderate antioxidative capacity.  From:  Sökmen, M., Serkedjieva, J., Daferera, D., Gulluce, M., Polissiou, M., Tepe, B., … & Sokmen, A. (2004). In vitro antioxidant, antimicrobial, and antiviral activities of the essential oil and various extracts from herbal parts and callus cultures of Origanum acutidens. Journal of agricultural and food chemistry, 52(11), 3309-3312.
• Nine plant spice essential oils were tested on various microorganisms (Salmonella typhimurium, Bacillus cereus, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Yersinia enterocolitica, Saccharomyces cerevisiae, Candida rugosa, Rhizopus oryzae and Aspergillus niger and showed antimicrobial activity and may be used to combat pathogenic and spoilage microorganisms, and improve shelf-life of foods.  They included: savory, laurel, oregano, basil, cumin, sea fennel, myrtle,and mint.  From:  Özcan, M., & Erkmen, O. (2001). Antimicrobial activity of the essential oils of Turkish plant spices. European Food Research and Technology, 212(6), 658-660
• The fungus; Penicillium digitatum, was inhibited completely by oregano, thyme, dictamus, and marjoram essential oils at low concentrations.  From:  Daferera, D. J., Ziogas, B. N., & Polissiou, M. G. (2000). GC-MS analysis of essential oils from some Greek aromatic plants and their fungitoxicity on Penicillium digitatum. Journal of Agricultural and Food Chemistry, 48(6), 2576-2581.
• Lippia graveolens (Mexican oregano) oil and its main component: carvacrol, inhibited different human and animal viruses in vitro.  From:  Pilau, M. R., Alves, S. H., Weiblen, R., Arenhart, S., Cueto, A. P., & Lovato, L. T. (2011). Antiviral activity of the Lippia graveolens (Mexican oregano) essential oil and its main compound carvacrol against human and animal viruses. Brazilian Journal of Microbiology, 42(4), 1616-1624.
• Cinnamomum zeylanicum (cinnamon), Lippia graveolens (Mexican oregano) , Origanum vulgare (oregano), Thymus vulgaris (thyme) and Zingiber officinale (ginger) essential oils showed antifungal activity.  From:  Pozzatti, P., Scheid, L. A., Spader, T. B., Atayde, M. L., Santurio, J. M., & Alves, S. H. (2008). In vitro activity of essential oils extracted from plants used as spices against fluconazole-resistant and fluconazole-susceptible Candida spp. Canadian journal of microbiology, 54(11), 950-956.
• Mentha piperita (peppermint), M. spicata (spearmint), Thymus vulgaris (thyme), Origanum vulgare (oregano), O. applii (oregano), Aloysia triphylla (lemon verbena), Ocimum gratissimum (basil), and O. basilicum (basil) were studied and demonstrated varying degrees of antimicrobial activity.  From:  Sartoratto, A., Machado, A. L. M., Delarmelina, C., Figueira, G. M., Duarte, M. C. T., & Rehder, V. L. G. (2004). Composition and antimicrobial activity of essential oils from aromatic plants used in Brazil. Brazilian Journal of Microbiology, 35(4), 275-280.
• Origanum minutiflorum (oregano), Laurus nobilis (bay), Lavandula stoechas (lavender) and Foeniculum vulgare (fennel) were effective against  the following foodborne pathogens: Escherichia coli, Listeria monocytogenes, Salmonella typhimurium, and Staphylococcus aureus. Constituents included carvacrol, 1,8-cineole, fenchone, and trans-anethole.  From:  Dadalioglu, I., & Evrendilek, G. A. (2004). Chemical compositions and antibacterial effects of essential oils of Turkish oregano (Origanum minutiflorum), bay laurel (Laurus nobilis), Spanish lavender (Lavandula stoechas L.), and fennel (Foeniculum vulgare) on common foodborne pathogens. Journal of agricultural and food chemistry, 52(26), 8255-8260.
• Laurus nobilis (bay), salvia officinalis (sage), rosmarinus officinalis (rosemary), origanum vulgare (oregano), and coriandrum sativum (coriander) demonstrated antimicrobial, antioxidant activity, with oregano being the strongest.  From:  Baratta, M. T., Dorman, H. D., Deans, S. G., Biondi, D. M., & Ruberto, G. (1998). Chemical composition, antimicrobial and antioxidative activity of laurel, sage, rosemary, oregano and coriander essential oils. Journal of Essential Oil Research, 10(6), 618-627.
• Origanum vulgare (oregano), Thymus vulgaris (thyme), Lavandula angustifolia (lavender) , Mentha piperita (peppermint), and Melaleuca alternifolia (tea tree) were tested against 32 erythromycin-resistant streptococci; oregano, thyme, and the carvacrol constituent showed the strongest antimicrobial activity.  From:  Magi, G., Marini, E., & Facinelli, B. (2015). Antimicrobial activity of essential oils and carvacrol, and synergy of carvacrol and erythromycin, against clinical, erythromycin-resistant Group A Streptococci. Frontiers in microbiology, 6, 165.
• Citrus aurantium (bergamot), C. limon (lemon), Lavandula angustifolia (lavender), Matricaria chamomilla (chamomile), Mentha piperita (peppermint), M. spicata (spearmint), Ocimum basilicum (basil), Origanum vulgare(oregano), Thymus vulgaris (thyme), and Salvia officinalis (sage) along with their constituents were tested against human pathogenic bacteria.  The highest and broadest activity was shown by O. vulgare oil and carvacrol had the highest antibacterial activity among the tested constituents.  Other significant constituents included: camphor, 1,8-cineole, linalool, linalyl acetate, limonene, menthol, a-pinene, b-pinene, and thymol.  From:  Soković, M., Glamočlija, J., Marin, P. D., Brkić, D., & van Griensven, L. J. (2010). Antibacterial effects of the essential oils of commonly consumed medicinal herbs using an in vitro model. Molecules, 15(11), 7532-7546.
• Antimicrobial, antioxidant, and anti-inflammatory activities of the essential oils of 18 plant species from Tajikistan were tested. The essential oil of Origanum tyttanthum showed a strong antibacterial and antioxidant activity and Galagania fragrantissima along with Origanum tyttanthum had the highest anti-inflammatory activity.  From:  Sharopov, F., Braun, M. S., Gulmurodov, I., Khalifaev, D., Isupov, S., & Wink, M. (2015). Antimicrobial, Antioxidant, and Anti-Inflammatory Activities of Essential Oils of Selected Aromatic Plants from Tajikistan. Foods, 4(4), 645-653.
• Piper nigrum (black pepper), Syzygium aromaticum (clove), Pelargonium graveolens (geranium), Myristica fragrans (nutmeg), Origanum vulgare (oregano),  and Thymus vulgaris (thyme) were assessed for antibacterial activity against 25 different genera of bacteria.  From:  Dorman, H. J. D., & Deans, S. G. (2000). Antimicrobial agents from plants: antibacterial activity of plant volatile oils. Journal of applied microbiology, 88(2), 308-316.
• Cinnamon, oregano, savory, thyme, clove, lemongrass, cajuput, and allspice showed antibacterial activity against meat spoilage bacteria.  From:  Oussalah, M., Caillet, S., Saucier, L., & Lacroix, M. (2006). Antimicrobial effects of selected plant essential oils on the growth of a Pseudomonas putida strain isolated from meat. Meat science, 73(2), 236-244.
• Carvacrol and eugenol had an anticandidal effect. From:  Chami, N., Bennis, S., Chami, F., Aboussekhra, A., & Remmal, A. (2005). Study of anticandidal activity of carvacrol and eugenol in vitro and in vivo. Oral microbiology and immunology, 20(2), 106-111.
• Clove and oregano oils were antifungal against the yeast: Saccharomyces cerevisiae.  From:  Chami, F., Chami, N., Bennis, S., Bouchikhi, T., & Remmal, A. (2005). Oregano and clove essential oils induce surface alteration of Saccharomyces cerevisiae. Phytotherapy Research, 19(5), 405-408
• 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.
• Sixteen essential oils and forty-two pure constituents were tested against Candida albicans. Origanum vulgare, Satureja montana, Mentha piperita, Cinnamomum verum, and Cymbopogon flexuosus along with the  pure constituents (by family) of , β-phellandrene, carvacrol, 1-decanol, and trans-cynnamaldehyde.  From:  Tampieri, M. P., Galuppi, R., Macchioni, F., Carelle, M. S., Falcioni, L., Cioni, P. L., & Morelli, I. (2005). The inhibition of Candida albicans by selected essential oils and their major components. Mycopathologia, 159(3), 339-345.
• This study evaluated the in vitro antioxidant and antibacterial properties of oregano (Origanum vulgare) essential oil and extracts. From:  Teixeira, B., Marques, A., Ramos, C., Serrano, C., Matos, O., Neng, N. R., … & Nunes, M. L. (2013). Chemical composition and bioactivity of different oregano (Origanum vulgare) extracts and essential oil. Journal of the Science of Food and Agriculture, 93(11), 2707-2714.
• Oregano virens was antifungal against candida species. From:  Salgueiro, L. R., Cavaleiro, C., Pinto, E., Pina-Vaz, C., Rodrigues, A. G., Palmeira, A., … & Martinez-de-Oliveira, J. (2003). Chemical composition and antifungal activity of the essential oil of Origanum virens on Candida species. Planta medica, 69(09), 871-874.
• Salad preservation was lengthened with the essential oils ofthyme verbena, thyme, oregano, ajowan, tea tree, clove, sage, and rosemary.  From:  Molinos, A. C., Abriouel, H., López, R. L., Omar, N. B., Valdivia, E., & Gálvez, A. (2009). Enhanced bactericidal activity of enterocin AS-48 in combination with essential oils, natural bioactive compounds and chemical preservatives against Listeria monocytogenes in ready-to-eat salad. Food and Chemical Toxicology, 47(9), 2216-2223.
• O. acutidens oil, carvacrol and thymol completely inhibited mycelial growth of multiple fungi.  The oil, carvacrol and thymol showed a potent phytotoxic effect against the plants tested.  Oregano also showed insecticidal activity against multiple pests tested.  From:  Kordali, S., Cakir, A., Ozer, H., Cakmakci, R., Kesdek, M., & Mete, E. (2008). Antifungal, phytotoxic and insecticidal properties of essential oil isolated from Turkish Origanum acutidens and its three components, carvacrol, thymol and p-cymene. Bioresource Technology, 99(18), 8788-8795.
• Basil, clove, garlic, horseradish, marjoram, oregano, rosemary, and thyme exhibited antibacterial activities on a foodborne pathogen, Vibrio parahaemolyticus.  From:  Yano, Y., Satomi, M., & Oikawa, H. (2006). Antimicrobial effect of spices and herbs on Vibrio parahaemolyticus. International journal of food microbiology, 111(1), 6-11.
• Oregano oils possessed anti-influenza virus activities, although less than a potent Echinacea preparation, and with greater potential for  toxicity of lung epthelial cells.  From:  Vimalanathan, S., & Hudson, J. (2012). Anti-Influenza virus activities of commercial oregano oils and their carriers. Journal of Applied Pharmaceutical Science, 2(7), 214.
• Thirty essential oils were tested against pathogenic plant bacteria. Ceylon cinnamon (leaf and bark), oregano, clove bud, palmarosa, basil, peppermint, rosemary, blue gum, camphor, lemongrass, aniseed, ylang ylang, silver fir, lemon, dwarf mountain pine, bay laurel, scots pine, black cumin, Indian frankincense, bergamot orange, common juniper, bitter orange, and neem showed varying degrees of reaction.  From: Popović, T., Milićević, Z., Oro, V., Kostić, I., Radović, V., Jelušić, A., & Krnjajić, S. (2018). A preliminary study of antibacterial activity of thirty essential oils against several important plant pathogenic bacteria. Pesticidi i fitomedicina, 33(3-4), 185-195.
• The following essential oils were tested and showed varying degrees of antimicrobial, antifungal, antibacterial, and antiviral activities: Anethum graveolens, Foeniculum vulgare, Mentha piperita, Mentha spicata, Lavandula officinalis, Ocimum basilicum, Origanum onites, O. vulgare, O. munitiflorum, O. majorana, Rosmarinus officinalis, Salvia officinalis, and Satureja cuneifolia. From: Orhan, İlkay Erdoğan, et al. “Antimicrobial and antiviral effects of essential oils from selected Umbelliferae and Labiatae plants and individual essential oil components.” Turkish Journal of Biology 36.3 (2012): 239-246.

​INSECTICIDAL / PESTICIDAL / REPELLENT / ANTIPARASITE

• ​Fumigant vapours from anise (Pimpinella anisum), cumin (Cuminum cyminum), eucalyptus (Eucalyptus camaldulensis), oregano (Origanum syriacum) and rosemary (Rosmarinus officinalis) were tested against the packaged food pests: Tribolium confusum and Ephestia kuehniella. Anise and cumin resulted in 100% mortality of the eggs.  Oregano achieved 77% mortality in T. confusum and 89% in E. kuehniella. Eucalyptus and rosemary achieved up to 45 and 65% mortality, respectively.  From:  Tunc, I., Berger, B. M., Erler, F., & Dağlı, F. (2000). Ovicidal activity of essential oils from five plants against two stored-product insects. Journal of Stored Products Research, 36(2), 161-168.
• Apium graveolens (celery), Citrus sinensis (orange), Eucalyptus globulus (eucalyptus), Juniperus oxycedrus (juniper), Laurus nobilis (bay), Lavandula hybrida (lavender), Mentha microphylla (mint), Mentha viridis (spearmint), Ocimum basilicum (basil), Origanum vulgare (oregano), Pistacia terebinthus (turpentine tree), Rosmarinus officinalis (rosemary), and Thuja orientalis (thuja) were effective insect repellents against Acanthoscelides obtectus.  From:  Papachristos, D. P., & Stamopoulos, D. C. (2002). Repellent, toxic and reproduction inhibitory effects of essential oil vapours on Acanthoscelides obtectus (Say)(Coleoptera: Bruchidae). Journal of Stored Products Research, 38(2), 117-128.
• Origanum onites  and its carvacrol constituent were acaricidal against the tick R. turanicus.  From:  Coskun, S., Girisgin, O., Kürkcüoglu, M., Malyer, H., Girisgin, A. O., Kırımer, N., & Baser, K. H. (2008). Acaricidal efficacy of Origanum onites L. essential oil against Rhipicephalus turanicus (Ixodidae). Parasitology research, 103(2), 259-261.
• Origanum minutiflorum increased tick mortality of Rhipicephalus turanicus. From:  Cetin, H., Cilek, J. E., Aydin, L., & Yanikoglu, A. (2009). Acaricidal effects of the essential oil of Origanum minutiflorum (Lamiaceae) against Rhipicephalus turanicus (Acari: Ixodidae). Veterinary parasitology, 160(3), 359-361.
• Turkish oregano essential oil and its two components, carvacrol and thymol were insecticidal against the pine moth.  From:  Cetin, H., Erler, F., & Yanikoglu, A. (2007). A comparative evaluation of Origanum onites essential oil and its four major components as larvicides against the pine processionary moth, Thaumetopoea wilkinsoni Tams. Pest management science, 63(8), 830-833.
• Essential oils from Cymbopogon martinii “palmarosa”, Cymbopogon flexuosus “lemongrass”, and Lippia origanoides “wild oregano” were insecticidal against Tribolium castaneum.  From:  Caballero-Gallardo, K., Olivero-Verbel, J., & Stashenko, E. E. (2012). Repellency and toxicity of essential oils from Cymbopogon martinii, Cymbopogon flexuosus and Lippia origanoides cultivated in Colombia against Tribolium castaneum. Journal of Stored Products Research, 50, 62-65.   ​
• O. acutidens oil, carvacrol and thymol completely inhibited mycelial growth of multiple fungi.  The oil, carvacrol and thymol showed a potent phytotoxic effect against the plants tested.  Oregano also showed insecticidal activity against multiple pests tested.  From:  Kordali, S., Cakir, A., Ozer, H., Cakmakci, R., Kesdek, M., & Mete, E. (2008). Antifungal, phytotoxic and insecticidal properties of essential oil isolated from Turkish Origanum acutidens and its three components, carvacrol, thymol and p-cymene. Bioresource Technology, 99(18), 8788-8795.
• Oregano and thyme essential oils were effective against T. cruzi.  From:  Santoro, G. F., das Graças Cardoso, M., Guimarães, L. G. L., Salgado, A. P. S., Menna-Barreto, R. F., & Soares, M. J. (2007). Effect of oregano (Origanum vulgare L.) and thyme (Thymus vulgaris L.) essential oils on Trypanosoma cruzi (Protozoa: Kinetoplastida) growth and ultrastructure. Parasitology research, 100(4), 783-790
• Tested in vitro, Justicia spicigera (honeysuckle), Lipia beriandieri (oregano), Psidium guajava (guava), Punica granutus (granado) Magnifera indica (mango), Plantago major (plantain), and Cupressus semperbirens (cedar) showed antigiardiasic activity against the human intestinal parasite.  From:  Ponce-Macotela, M., Navarro-Alegria, I., Martinez-Gordillo, M. N., & Alvarez-Chacon, R. (1993). In vitro effect against Giardia of 14 plant extracts. Revista de investigacion clinica; organo del Hospital de Enfermedades de la Nutricion, 46(5), 343-347.
• Manuka, clove, and oregano were larvicidal against a mosquitoe species.  From:  Muturi, E. J., Ramirez, J. L., Doll, K. M., & Bowman, M. J. (2017). Combined toxicity of three essential oils against Aedes aegypti (Diptera: Culicidae) larvae. Journal of medical entomology, 54(6), 1684-1691.

​ANTICANCER / ANTI-TUMOR

• The extracts of O syriacum (oregano), L nobilis (bay), and S triloba (sage) showed antiproliferative, antitumor activity to adenocarcinoma of breast cells.  From:  Al-Kalaldeh, J. Z., Abu-Dahab, R., & Afifi, F. U. (2010). Volatile oil composition and antiproliferative activity of Laurus nobilis, Origanum syriacum, Origanum vulgare, and Salvia triloba against human breast adenocarcinoma cells. Nutrition Research, 30(4), 271-278.
• Constituents from O. vulgare showed inhibition of thrombin and activity against leukemia cancer cells.  From:  Goun, E., Cunningham, G., Solodnikov, S., Krasnykch, O., & Miles, H. (2002). Antithrombin activity of some constituents from Origanum vulgare. Fitoterapia, 73(7), 692-694.
• Carvacrol inhibited lung cancer cell growth in vitro.  From:  Koparal, A. T., & Zeytinoğlu, M. (2003). Effects of carvacrol on a human non-small cell lung cancer (NSCLC) cell line, A549. In Animal Cell Technology: Basic & Applied Aspects (pp. 207-211). Springer Netherlands.
• Oregano extract had a cytotoxic effect on human colon cancer cells.  From:  Savini, I., Arnone, R., Catani, M. V., & Avigliano, L. (2009). Origanum vulgare induces apoptosis in human colon cancer caco2 cells. Nutrition and cancer, 61(3), 381-389.
• Oregano inhibited colon cancer cells in rats.  From:  Srihari, T., Balasubramaniyan, V., & Nalini, N. (2008). Role of oregano on bacterial enzymes in 1, 2-dimethylhydrazine-induced experimental colon carcinogenesis. Canadian journal of physiology and pharmacology, 86(10), 667-674.

ANTIOXIDANT

• Geranium, monarda, nutmeg, oregano and thyme essential oils were evaluated for, and all demonstrated antioxidant capabilities.  From:  Damien Dorman, H. J., Deans, S. G., Noble, R. C., & Surai, P. (1995). Evaluation in vitro of plant essential oils as natural antioxidants. Journal of Essential Oil Research, 7(6), 645-651.
• Strong antioxidant activity was observed in polar extracts of Lycopus europaeus, Melissa officinalis, Origanum vulgare and Lavandula latifolia.  Phlomis lychnitis, Salvia pratensis and Calamintha sylvatica caused the highest fungal inhibition. From:  López, V., Akerreta, S., Casanova, E., García-Mina, J. M., Cavero, R. Y., & Calvo, M. I. (2007). In vitro antioxidant and anti-rhizopus activities of Lamiaceae herbal extracts. Plant foods for human nutrition, 62(4), 151-155.
• Species of thyme, savory, sweet marjoram, and oregano showed varying types of antioxidant abilities.  From:  Dorman, H. D., Bachmayer, O., Kosar, M., & Hiltunen, R. (2004). Antioxidant properties of aqueous extracts from selected Lamiaceae species grown in Turkey. Journal of Agricultural and Food Chemistry, 52(4), 762-770.
• Dried oregano leaves had radical scavenging activity.  From:  Matsuura, H., Chiji, H., Asakawa, C., Amano, M., Yoshihara, T., & Mizutani, J. (2003). DPPH radical scavengers from dried leaves of oregano (Origanum vulgare). Bioscience, biotechnology, and biochemistry, 67(11), 2311-2316.
• Sage, oregano and rosemary protected against hydrogen peroxide DNA damage in the mouse tail, and only sage protected against cytotoxicity.  From:  Aherne, S. A., Kerry, J. P., & O’Brien, N. M. (2007). Effects of plant extracts on antioxidant status and oxidant-induced stress in Caco-2 cells. British Journal of Nutrition, 97(02), 321-328.
• Oregano species variability and radical scavenging properties were assessed.  From:  Dambolena, J. S., Zunino, M. P., Lucini, E. I., Olmedo, R., Banchio, E., Bima, P. J., & Zygadlo, J. A. (2009). Total phenolic content, radical scavenging properties, and essential oil composition of origanum species from different populations. Journal of agricultural and food chemistry, 58(2), 1115-1120.
• 423 essential oils from 48 different botanical families were evaluated for their antioxidant activities as free radical scavenging agents.  Results identified oils of the botanical families Lamiaceae and Myrtaceae as the most effective antioxidants, with thymol, eugenol, and carvacrol being the major constituents. From:  Anthony, K. P., Deolu‐Sobogun, S. A., & Saleh, M. A. (2012). Comprehensive assessment of antioxidant activity of essential oils. Journal of food science, 77(8), C839-C843.
• Oregano essential oil ingestion improved the antioxidant capacity of rabbit tissue. From:  Botsoglou, N. A., Florou-Paneri, P., Christaki, E., Giannenas, I., & Spais, A. B. (2004). Performance of rabbits and oxidative stability of muscle tissues as affected by dietary supplementation with oregano essential oil. Archives of Animal Nutrition, 58(3), 209-218.
• Dietary oregano improved antioxidant status in toxic rats.  From:  Botsoglou, N. A., Taitzoglou, I. A., Botsoglou, E., Lavrentiadou, S. N., Kokoli, A. N., & Roubies, N. (2008). Effect of long-term dietary administration of Oregano on the alleviation of carbon tetrachloride-induced oxidative stress in rats. Journal of agricultural and food chemistry, 56(15), 6287-6293.
• Oregano showed the strongest antioxidant, antimicrobial activity in vitro.  From:  Lagouri, V., Guldas, M., & Gurbuz, O. (2011). In vitro antioxidant/free radical scavenging and antibacterial properties of endemic oregano and thyme extracts from Greece. Food Science and Biotechnology, 20(6), 1487-1493.
• Seven Bulgarian medicinal plants were with high phenolics content and antioxidant properties: Pulmonaria officinalis, Hypericum perforatum, Agrimonia eupatoria, Origanum vulgare, Melissa officinalis, Rubus sp. Diversa, and Cotinus coggygria.  From:  Ivanova, D., Gerova, D., Chervenkov, T., & Yankova, T. (2005). Polyphenols and antioxidant capacity of Bulgarian medicinal plants. Journal of ethnopharmacology, 96(1), 145-150.
• Clove, cumin, oregano, and anise essential oils may be a  potential source of natural antioxidant and antimicrobial agents.  From:  Raeisi, M., Hashemi, M., Aminzare, M., Sadeghi, M., Jahani, T., Keshavarzi, H., … & Tepe, B. (2016). Comparative Evaluation of Phytochemical, Antioxidant, and Antibacterial Properties from the Essential Oils of Four Commonly Consuming Plants in Iran. Journal of food quality and hazards control, 3(3), 107-113.
• Melissa officinalis, Mentha piperita, and Origanum vulgare demonstrated varying degrees of antioxidant activity depending on fresh or dried, and related to phenolic constituents.  From:  Capecka, E., Mareczek, A., & Leja, M. (2005). Antioxidant activity of fresh and dry herbs of some Lamiaceae species. Food chemistry, 93(2), 223-226.
• The following dried herbs tested contained high amounts of antioxidant content:  oregano, sage, peppermint, thyme, lemon balm, clove, allspice, cinnamon, and a few additional Chinese medicinal herbs.   From:  Dragland, S., Senoo, H., Wake, K., Holte, K., & Blomhoff, R. (2003). Several culinary and medicinal herbs are important sources of dietary antioxidants. The Journal of nutrition, 133(5), 1286-1290.
• The extracts of O. basilicum (basil) and O. vulgare (oregano) expressed very strong radical scavenging activity.  From:  Kaurinovic, B., Popovic, M., Vlaisavljevic, S., & Trivic, S. (2011). Antioxidant capacity of Ocimum basilicum L. and Origanum vulgare L. extracts. Molecules, 16(9), 7401-7414.
• Rosemary has been extensively studied as a natural antioxidants with sage and oregano gaining interest for their antioxidant potential.  From:  Yanishlieva, N. V., Marinova, E., & Pokorný, J. (2006). Natural antioxidants from herbs and spices. European Journal of lipid science and Technology, 108(9), 776-793.
• A highly positive linear relationship between antioxidant capacity and total phenolic content exists with major types of phenolic constituents from spice extracts being phenolic acids, phenolic diterpenes, flavonoids, and volatile oils. Rosmarinic acid was the dominant phenolic compound and the spices and related families with the highest antioxidant capacity were clove in the Myrtaceae, cinnamon in the Lauraceae, and oregano in the Labiatae.  From:  Shan, B., Cai, Y. Z., Sun, M., & Corke, H. (2005). Antioxidant capacity of 26 spice extracts and characterization of their phenolic constituents. Journal of agricultural and food chemistry, 53(20), 7749-7759.

PRESERVATIVE

• Rosemary and oregano extracts had stronger antioxidant properties than common food additives tested.  From:  Martínez-Tomé, M., Jiménez, A. M., Ruggieri, S., Frega, N., Strabbioli, R., & Murcia, M. A. (2001). Antioxidant properties of Mediterranean spices compared with common food additives. Journal of food protection, 64(9), 1412-1419.
• Essential oils of cilantro, coriander, cinnamon, oregano, rosemary, sage, clove, thyme, lemongrass, turmeric, mint, basil, and constituents of linalool, cinnamaldehyde, carvacrol, thymol, terpinene, cymene, alpha/beta pinene, bornyl acetate, camphor, 1,8-cineole, alpha terpeneol, geraniol, perrilaldehyde, and eugenol have demonstrated food preserving potential.  From:  Burt, S. (2004). Essential oils: their antibacterial properties and potential applications in foods—a review. International journal of food microbiology, 94(3), 223-253.

HEPATOPROTECTIVE

• Carvacrol had a significant hepatoprotective and antioxidant effect in rats. From:  Aristatile, B., Al‐Numair, K. S., Veeramani, C., & Pugalendi, K. V. (2009). Effect of carvacrol on hepatic marker enzymes and antioxidant status in d‐galactosamine‐induced hepatotoxicity in rats. Fundamental & clinical pharmacology, 23(6), 757-765.
• Carvacrol protects the liver against defects caused by ischemia and reperfusion without being toxic in rats.  From:  Canbek, M., Uyanoglu, M., Bayramoglu, G., Senturk, H., Erkasap, N., Koken, T., … & Baser, K. H. C. (2008). Effects of carvacrol on defects of ischemia-reperfusion in the rat liver. Phytomedicine, 15(6), 447-452.

​RESPIRATORY HEALTH

• This article summarized the use of Eucalyptus citriodora, Eucalyptus globulus, Mentha piperita, Origanum syriacum, Salvia fruticosa and Rosmarinus officinalis in treating respiratory ailments.  From:  Rakover, Y., Ben-Arye, E., & Goldstein, L. H. (2008). The treatment of respiratory ailments with essential oils of some aromatic medicinal plants. Harefuah, 147(10), 783-8.

DIGESTIVE HEALTH

• Oregano essential oil applied colorectal, reduced colonic injury in rats.  From:  Dundar, E., Olgun, E. G., Isiksoy, S., Kurkcuoglu, M., Baser, K. H. C., & Bal, C. (2008). The effects of intra-rectal and intra-peritoneal application of Origanum onites L. essential oil on 2, 4, 6-trinitrobenzenesulfonic acid-induced colitis in the rat. Experimental and Toxicologic Pathology, 59(6), 399-408.
• Thyme and oregano essential reduced inflammation and colitis in mice.  From:  Bukovská, A., Cikoš, Š., Juhás, Š., Il’ková, G., Rehák, P., & Koppel, J. (2007). Effects of a combination of thyme and oregano essential oils on TNBS-induced colitis in mice. Mediators of inflammation, 2007.
• Oreganum vulgare was orally administered to 14 adult patients whose stools tested positive for enteric parasites, reducing the incidence of, Blastocystis hominis, Entamoeba hartmanni and Endolimax nana, and improving gastrointestinal symptoms.  From:  Force, M., Sparks, W. S., & Ronzio, R. A. (2000). Inhibition of enteric parasites by emulsified oil of oregano in vivo. Phytotherapy Research, 14(3), 213-214
• Cinnamon, clove, oregano, and thyme at the right dose can reduce E. coli with minimal intestine cell cytotoxicity.  From:  Dušan, F., Marián, S., Katarína, D., & Dobroslava, B. (2006). Essential oils—their antimicrobial activity against Escherichia coli and effect on intestinal cell viability. Toxicology in vitro, 20(8), 1435-1445.
• Carvacrol reduced inflammation in paw edema, likely  interfering with the release / synthesis of inflammatory mediators like prostanoids, and may be useful in healing gastric ulcers.  From:  Silva, F. V., Guimarães, A. G., Silva, E. R., Sousa-Neto, B. P., Machado, F. D., Quintans-Júnior, L. J., … & Oliveira, R. C. (2012). Anti-inflammatory and anti-ulcer activities of carvacrol, a monoterpene present in the essential oil of oregano. Journal of medicinal food, 15(11), 984-991.
• The following methanol extracts showed activity against Helicobacter pylori which causes gastrointestinal disorders:  Myristica fragrans (nutmeg seed), Zingiber officinale (ginger root), Rosmarinus officinalis (rosemary leaf), Achillea millefolium (yarrow), Foeniculum vulgare (fennel seed), Passiflora incarnata (passionflower), Origanum majorana (oregano), and others.  From:  Mahady, G. B., Pendland, S. L., Stoia, A., Hamill, F. A., Fabricant, D., Dietz, B. M., & Chadwick, L. R. (2005). In vitro susceptibility of Helicobacter pylori to botanical extracts used traditionally for the treatment of gastrointestinal disorders. Phytotherapy research, 19(11), 988-991.

CHOLESTEROL LOWERING

• Thyme and oregano tea infusions affected LDL in vitro.  From:  Kulišić, T., Kriško, A., Dragović-Uzelac, V., Miloš, M., & Pifat, G. (2007). The effects of essential oils and aqueous tea infusions of oregano (Origanum vulgare L. spp. hirtum), thyme (Thymus vulgaris L.) and wild thyme (Thymus serpyllum L.) on the copper-induced oxidation of human low-density lipoproteins. International journal of food sciences and nutrition, 58(2), 87-93.

ANTI-DIABETIC

• Oregano, rosemary, clove, and other plants showed positive glycation inhibitory and antioxidative activities that could be useful in treating diabetes. From:  Kim, H. Y., & Kim, K. (2003). Protein glycation inhibitory and antioxidative activities of some plant extracts in vitro. Journal of agricultural and food chemistry, 51(6), 1586-1591.
• Oregano, rosemary, and lemon balm showed in vitro action that might be useful in treating diabetes and hypertension.  From:  Kwon, Y. I. I., Vattem, D. A., & Shetty, K. (2006). Evaluation of clonal herbs of Lamiaceae species for management of diabetes and hypertension. Asia pacific journal of clinical nutrition, 15(1), 107-118.
• Extracts of O. vulgare had an anti-hyperglycaemic effect in rats without affecting basal plasma insulin levels.  From:  Lemhadri, A., Zeggwagh, N. A., Maghrani, M., Jouad, H., & Eddouks, M. (2004). Anti-hyperglycaemic activity of the aqueous extract of Origanum vulgare growing wild in Tafilalet region. Journal of ethnopharmacology, 92(2), 251-256.
• Oregano extracts may be useful in treating hyperglycemia.  ​From: McCue, P., Vattem, D., & Shetty, K. (2004). Inhibitory effect of clonal oregano extracts against porcine pancreatic amylase in vitro. Asia Pacific journal of clinical nutrition, 13(4), 401-408.
• Oregano extract could reduce ameliorate metabolic syndrome related to hypertension and hyperglycemia.  From:  Mueller, M., Lukas, B., Novak, J., Simoncini, T., Genazzani, A. R., & Jungbauer, A. (2008). Oregano: a source for peroxisome proliferator-activated receptor γ antagonists. Journal of agricultural and food chemistry, 56(24), 11621-11630.
• Different combinations of essential oils including fenugreek, cinnamon, cumin, and oregano, were studied for their ability to lower blood glucose levels.  From:  Talpur, N., Echard, B., Ingram, C., Bagchi, D., & Preuss, H. (2005). Effects of a novel formulation of essential oils on glucose–insulin metabolism in diabetic and hypertensive rats: a pilot study. Diabetes, Obesity and Metabolism, 7(2), 193-199.

​ANTI-INFLAMMATORY

• In mice, oregano extract demonstrated anti-inflammatory activities but tended to be weaker than those of hydrocortisone. It also showed antioxidant activities which could contribute to its preventive effects against inflammatory diseases, like gastritis and contact hypersensitivity.  From:  Yoshino, K., Higashi, N., & Koga, K. (2006). Antioxidant and antiinflammatory activities of oregano extract. Journal of health science, 52(2), 169-173.

CARDIAC HEALTH

• Oregano in vitro had an anti-inflammatory effect in a cellular model of atherosclerosis.  From:  Ocana-Fuentes, A., Arranz-Gutierrez, E., Senorans, F. J., & Reglero, G. (2010). Supercritical fluid extraction of oregano (Origanum vulgare) essentials oils: anti-inflammatory properties based on cytokine response on THP-1 macrophages. Food and Chemical Toxicology, 48(6), 1568-1575.  Link:  http://dx.doi.org/10.1016/j.fct.2010.03.026
• Patients with mild hyperlipidemia who consumed Origanum onites distillate had reduced  lipid profiles, antioxidant status and endothelial function.  From:  Özdemir, B., Ekbul, A., Topal, N. B., Sarandöl, E., Sağ, S., Başer, K. H. C., … & Aydinlar, A. (2008). Effects of Origanum onites on endothelial function and serum biochemical markers in hyperlipidaemic patients. Journal of International Medical Research, 36(6), 1326-1334.

SKIN / WOUND

• Origanoside extracted from O. vulgare had a skin whitening effect.  From: Liang, C. H., Chou, T. H., & Ding, H. Y. (2010). Inhibition of melanogensis by a novel origanoside from Origanum vulgare. Journal of dermatological science, 57(3), 170-177.
• Oregano extract ointment decreased bacterial contamination and related skin infection on post-surgical wounds. From:  Ragi, J., Pappert, A., Rao, B., Havkin-Frenkel, D., & Milgraum, S. (2011). Oregano extract ointment for wound healing: a randomized, double-blind, petrolatum-controlled study evaluating efficacy. Journal of drugs in dermatology: JDD, 10(10), 1168-1172.
• In a study of 50 patients with wound ulcers, an herbal ointment was applied twice a day for 28 days. It contained Symphytum officinale, Plantago major, Calendula officinalis, Matricaria chamomilla, Bellis perennis, Achillea millefolium, Salvia officinalis, Hypericum perforatum, Olea europaea, Lavandula officinalis, Melaleuca alternifolia, Cympobogon martini, Origanum vulgare, Eugenia caryophyllata, Thymus vulgaris ct. thymol, Cera alba, honey, and glycerol. Results showed significant healing of wounds. From: Oreščanin, V. (2016). Treatment of pressure ulcers with Bioapifit® wound healing herbal ointment-a preliminary study. IJRDO: J Biol Sci, 2(10), 1-15.
• In this review of human studies on herbs for wound healing, the following plants were discussed: Aloe vera, Salvia miltiorrhizia, Alchemilla vulgaris, Angelica sinensis, Origanum vulgare, Lavandula stoechas, Radix astragalis, Rehmanniae radix, Ageratina pichinchensis, Calendula officianalis, and Mimosa tenuiflora. From: Lordani, T. V. A., de Lara, C. E., Ferreira, F. B. P., de Souza Terron Monich, M., Mesquita da Silva, C., Lordani, F., … & Lonardoni, M. V. C. (2018). Therapeutic effects of medicinal plants on cutaneous wound healing in humans: A systematic review. Mediators of inflammation, 2018.

GENERAL HEALTH

• Eating oregano improved reproduction of sows.  From:  Amrik, B., & Bilkei, G. (2004). Influence of farm application of oregano on performances of sows. The Canadian Veterinary Journal, 45(8), 674.

GREEN GARDENING

• Thirty essential oils were tested against pathogenic plant bacteria. Ceylon cinnamon (leaf and bark), oregano, clove bud, palmarosa, basil, peppermint, rosemary, blue gum, camphor, lemongrass, aniseed, ylang ylang, silver fir, lemon, dwarf mountain pine, bay laurel, scots pine, black cumin, Indian frankincense, bergamot orange, common juniper, bitter orange, and neem showed varying degrees of reaction.  From: Popović, T., Milićević, Z., Oro, V., Kostić, I., Radović, V., Jelušić, A., & Krnjajić, S. (2018). A preliminary study of antibacterial activity of thirty essential oils against several important plant pathogenic bacteria. Pesticidi i fitomedicina, 33(3-4), 185-195.

ATHLETE’S FOOT

• Penicillium digitatum fungus was inhibited completely by oregano, thyme, dictamus, and marjoram essential oils at low concentrations. From:  Daferera, D. J., Ziogas, B. N., & Polissiou, M. G. (2000). GC-MS analysis of essential oils from some Greek aromatic plants and their fungitoxicity on Penicillium digitatum. Journal of Agricultural and Food Chemistry, 48(6), 2576-2581.
• The following essential oils and blends showed antifungal action against Trichophyton interdigitale when applied to cotton: oregano, cinnamon, and the combination of origanum/clove/orange and clove/lavender/cinnamon. This may be useful in making footwear to prevent foot fungus. From:   Berechet, M. D., Chirilă, C., & Deselnicu, V. (2016). Antifungal Activity of Some Essential Oils on Cotton Fabrics. In International Conference on Advanced Materials and Systems (ICAMS) (pp. 197-202). The National Research & Development Institute for Textiles and Leather-INCDTP.
• Oregano, thyme, cinnamon bark, lemongrass, clove, palmarosa, peppermint, lavender, geranium Bourbon, and tea tree reduced fungus in heated footbath water.  From:  Inouye, S., Uchida, K., Nishiyama, Y., Hasumi, Y., Yamaguchi, H., & Abe, S. (2007). Combined effect of heat, essential oils and salt on the fungicidal activity against Trichophyton mentagrophytes in foot bath. Nippon Ishinkin Gakkai Zasshi, 48(1), 27-36.

By: Kathy Sadowski

Updated: 10/7/19