The listings of research below represent a compilation of scientific articles found on the topic, with a very brief overview description of each article/study. This compilation of research articles does not necessarily imply that there are adequate results to demonstrate safe and/or effective human use of any herb listed.
A large number of essential oils tested showed a range of activity against the bacteria that cause foot odor. From: Orchard, A., Viljoen, A., & van Vuuren, S. (2018). Antimicrobial essential oil combinations to combat foot odour. Planta medica, 84(09/10), 662-673.
This article summarized antimicrobial research on essential oils with strong research on topical and antiseptic uses, as penetration enhancers, and in fighting medicine resistant species. From: Solórzano-Santos, F., & Miranda-Novales, M. G. (2012). Essential oils from aromatic herbs as antimicrobial agents. Current opinion in biotechnology, 23(2), 136-141.
A thorough review of research on the antimicrobial, antibacterial, antifungal and antiviral activities of essential oils was provided. From: Reichling, J., Schnitzler, P., Suschke, U., & Saller, R. (2009). Essential oils of aromatic plants with antibacterial, antifungal, antiviral, and cytotoxic properties–an overview. Complementary Medicine Research, 16(2), 79-90.
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.
This mega analysis reviewed studies of essential oils as antibacterials in food. Several effective constituents included carvacrol, thymol, eugenol, perillaldehyde, cinnamaldehyde and cinnamic acid. These had minimum inhibitory concentrations with some having synergism such as carvacrol and p-cymene, cinnamaldehyde and eugenol, and between EO components and mild preservation methods. 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
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.
Citrus sinensis peel extracts were active against multiple tested human pathogenic bacteria. From: Mehmood, B., Dar, K. K., Ali, S., Awan, U. A., Nayyer, A. Q., Ghous, T., & Andleeb, S. (2015). In vitro assessment of antioxidant, antibacterial and phytochemical analysis of peel of Citrus sinensis. Pakistan journal of pharmaceutical sciences, 28(1).
Thymus vulgaris and Eucalyptus globulus showed antibacterial activity against Methicillin resistant Staphylococcus aureus (MRSA) and other tested bacterial strains. From: Tohidpour, A., Sattari, M., Omidbaigi, R., Yadegar, A., & Nazemi, J. (2010). Antibacterial effect of essential oils from two medicinal plants against Methicillin-resistant Staphylococcus aureus (MRSA). Phytomedicine, 17(2), 142-145.
A formulation containing Oliveria decumbens and Pelargonium graveolens essential oils improved healing of Staphylococcus aureus infected wounds in mice. From: Mahboubi, M., Feizabadi, M. M., Khamechian, T., Kazempour, N., Zadeh, M. R., Sasani, F., & Bekhradi, M. (2016). The effect of Oliveria decumbens and Pelargonium graveolens on healing of infected skin wounds in mice. World journal of plastic surgery, 5(3), 259.
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.
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.
Against meat bacteria in food: thyme, garlic and cinnamon showed the most antimicrobial activity. From: García-Díez, J., Alheiro, J., Falco, V., Fraqueza, M. J., & Patarata, L. (2016). Chemical characterization and antimicrobial properties of herbs and spices essential oils against pathogens and spoilage bacteria associated to dry-cured meat products. Journal of Essential Oil Research, 1-9.
Thymus algeriensis genuinus demonstrated a high inhibiting activity against eight bacterial strains and two species of fungus. Phenolic compounds demonstrated high antimicrobial activity. From: Chemat, S., Cherfouh, R., Meklati, B. Y., & Belanteur, K. (2012). Composition and microbial activity of thyme (Thymus algeriensis genuinus) essential oil. Journal of Essential Oil Research, 24(1), 5-11.
Iridoids from noni fruit demonstrated antimicrobial activity against multiple tested bacteria. From: West, B. J., Palmer, S. K., Deng, S., & Palu, A. K. (2012). Antimicrobial activity of an iridoid rich extract from” morinda citrifolia” fruit. Current Research Journal of Biological Sciences, 4(1), 52-54.
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.
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.
Orange, eucalyptus, fennel, geranium, juniper, peppermint, rosemary, purified turpentine, thyme, and Australian tea tree oil as well as the constituent of menthol showed antimicrobial and antiplasmid activities against the bacteria tested. From: Schelz, Z., Molnar, J., & Hohmann, J. (2006). Antimicrobial and antiplasmid activities of essential oils. Fitoterapia, 77(4), 279-285.
Myrrh gum resin showed antibacterial and antifungal action against tested microbes. From: Alhussaini, M. S., Saadabi, A. M., Alghonaim, M. I., & Ibrahim, K. E. (2015). An evaluation of the Antimicrobial activity of Commiphora myrrha Nees (Engl.) oleo-gum resins from Saudi Arabia. Journal of Medical Sciences, 15(4), 198.
Thyme, mint, and bay showed activity against food poisoning bacteria: Salmonella typhimurium, Staphylococcus aureus and Vibrio parahaemolyticus.From: Aktuğ, Ş. E., & Karapinar, M. (1986). Sensitivity of some common food-poisoning bacteria to thyme, mint and bay leaves. International Journal of Food Microbiology, 3(6), 349-354. L
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.
Garlic showed activity against human enteric bacteria. From: Ross, Z. M., O’Gara, E. A., Hill, D. J., Sleightholme, H. V., & Maslin, D. J. (2001). Antimicrobial properties of garlic oil against human enteric bacteria: evaluation of methodologies and comparisons with garlic oil sulfides and garlic powder. Applied and environmental microbiology, 67(1), 475-480.
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.
Palmarosa, lemongrass, peppermint, and eucalyptus were bactericidal against Escherichia coli. From: Pattnaik, S., Subramanyam, V. R., & Rath, C. C. (1994). Effect of essential oils on the viability and morphology of Escherichia coli (SP-11). Microbios, 84(340), 195-199.
Spearmint and dill were effective against the bacteria against Enterobacter cloacae with carvone and piperitone being active constituents. From: Rafii, F., & Shahverdi, A. R. (2006). Comparison of essential oils from three plants for enhancement of antimicrobial activity of nitrofurantoin against enterobacteria. Chemotherapy, 53(1), 21-25.
Peppermint essential oil showed antibacterial action dependant upon concentration, food pH, composition, storage temperature and the type of bacteria. From: Tassou, C. C., Drosinos, E. H., & Nychas, G. J. E. (1995). Effects of essential oil from mint (Mentha piperita) on Salmonella enteritidis and Listeria monocytogenes in model food systems at 4 and 10 C. Journal of Applied Bacteriology, 78(6), 593-600.
Melaleuca alternifolia, Thymus vulgaris, Mentha piperita and Rosmarinus officinalis were combined with conventional antimicrobials and assessed. From: Van Vuuren, S. F., Suliman, S., & Viljoen, A. M. (2009). The antimicrobial activity of four commercial essential oils in combination with conventional antimicrobials. Letters in applied microbiology, 48(4), 440-446.
Tea tree oil was antimicrobial against multiple tested pathogenic bacteria. Mumu, S. K., & Hossain, M. M. (2018). Antimicrobial activity of tea tree oil against pathogenic bacteria and comparison of its effectiveness with eucalyptus oil, lemongrass oil and conventional antibiotics. American Journal of Microbiological Research, 6(3), 73-78.
Rose absolute and essential oil contained high levels of phenolics and demonstrated strong antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Chromobacterium violaceum, and Erwinia carotovora. From: Ulusoy, S., Boşgelmez-Tınaz, G., & Seçilmiş-Canbay, H. (2009). Tocopherol, carotene, phenolic contents and antibacterial properties of rose essential oil, hydrosol and absolute. Current microbiology, 59(5), 554-558.
Vetiver was antimycobacterial against M. tuberculosis. From: Saikia, D., Parveen, S., Gupta, V. K., & Luqman, S. (2012). Anti-tuberculosis activity of Indian grass KHUS (Vetiveria zizanioides L. Nash). Complementary therapies in medicine, 20(6), 434-436.Link: http://dx.doi.org/10.1016/j.ctim.2012.07.010
Garlic extract inhibited oral bacteria. From: Bakri, I. M., & Douglas, C. W. I. (2005). Inhibitory effect of garlic extract on oral bacteria. Archives of Oral Biology, 50(7), 645-651.
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.
Myrrh essential oil and extracts were antimicroibial against multiple strains of the bacteria: S. aureus in vitro. From: Adam, M. E., & Selim, S. A. (2013). Antimicrobial activity of essential oil and methanol extract from Commiphora molmol (Engl.) resin. Int. J. Curr. Microbiol. App. Sci, 2(12), 1-6.
A variety of chile pepper species were active against multiple tested bacteria. From: Cichewicz, R. H., & Thorpe, P. A. (1996). The antimicrobial properties of chile peppers (Capsicum species) and their uses in Mayan medicine. Journal of ethnopharmacology, 52(2), 61-70.
These sesquiterpenoids sensitized bacteria to antibacterial drugs and may be useful as a combination treatment: nerolidol, bisabolol, apritone, and farnesol. From: Brehm-Stecher, B. F., & Johnson, E. A. (2003). Sensitization of Staphylococcus aureus and Escherichia coli to antibiotics by the sesquiterpenoids nerolidol, farnesol, bisabolol, and apritone. Antimicrobial agents and chemotherapy, 47(10), 3357-3360.
This study explained the antibacterial action of cinnamon and its major component, trans-cinnamaldehyde. From: Meades, G., Henken, R. L., Waldrop, G. L., Rahman, M. M., Gilman, S. D., Kamatou, G. P., … & Gibbons, S. (2010). Constituents of cinnamon inhibit bacterial acetyl CoA carboxylase. Planta medica, 76(14), 1570-1575.
Fourteen essential oils were tested against multiple bacteria and cinnamon bark, lemongrass and thyme oils showed the lowest minimal inhibitory dose. From: Inouye, S., Takizawa, T., & Yamaguchi, H. (2001). Antibacterial activity of essential oils and their major constituents against respiratory tract pathogens by gaseous contact. Journal of antimicrobial chemotherapy, 47(5), 565-573.
Cinnamon, clove, and thyme oils inhibited the bacteria: Aeromonas hydrophila. From: Fabio, A., Corona, A., Forte, E., & Quaglio, P. (2003). Inhibitory activity of spices and essential oils on psychrotrophic bacteria. The new microbiologica, 26(1), 115-120.
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.
Extracts from burdock were effective in vitro against tested mouth bacteria. From: Gentil, M., Pereira, J. V., Sousa, Y. T., Pietro, R., Neto, M. D. S., Vansan, L. P., & de Castro França, S. (2006). In vitro evaluation of the antibacterial activity of Arctium lappa as a phytotherapeutic agent used in intracanal dressings. Phytotherapy research, 20(3), 184-186.
Arctium lappa showed antimicrobial activity against endodontic pathogens. From: Pereira, J. V., Bergamo, D. C. B., Pereira, J. O., França, S. D. C., Pietro, R. C. L. R., & Silva-Sousa, Y. T. C. (2005). Antimicrobial activity of Arctium lappa constituents against microorganisms commonly found in endodontic infections. Brazilian dental journal, 16(3), 192-196.
Alnus rubra bark and catkins (red alder), Fragaria chiloensis leaves (strawberry), Moneses uniflora aerial parts, and Rhus glabra branches (sumac) showed the strongest antibacterial activity against 11 strains tested. From: McCutcheon, A. R., Ellis, S. M., Hancock, R. E. W., & Towers, G. H. N. (1992). Antibiotic screening of medicinal plants of the British Columbian native peoples. Journal of Ethnopharmacology, 37(3), 213-223. Link: http://dx.doi.org/10.1016/0378-8741(92)90036-Q
The study assessed the protective effect of plantain against S. pneumoniae in mice. From: Hetland, G., Samuelsen, A. B., Loslash, V., Paulsen, B. S., Aaberge, I. S., Groeng, E. C., & Michaelsen, T. E. (2000). Protective effect of Plantago major L. Pectin polysaccharide against systemic Streptococcus pneumoniae infection in mice. Scandinavian Journal of Immunology, 52(4), 348-355.
Rosemary essential oil and its constituents demonstrated antibacterial and antioxidant activities. Myrcene was the constituent associated with antioxidant activity and alpha pinene was a strong antibacterial. 1,8-cineole was effective against the E. coli bacteria. From: Ojeda-Sana, A. M., van Baren, C. M., Elechosa, M. A., Juárez, M. A., & Moreno, S. (2013). New insights into antibacterial and antioxidant activities of rosemary essential oils and their main components. Food Control, 31(1), 189-195.
Rosemary and its constituents carnasol and carnosic acid showed activity against the bacteria Staphylococcus aureus. From: Oluwatuyi, M., Kaatz, G. W., & Gibbons, S. (2004). Antibacterial and resistance modifying activity of Rosmarinus officinalis. Phytochemistry, 65(24), 3249-3254.
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
Along with other Yemen plants tested, Cupressus sempervirens (cypress), demonstrated a growth inhibitory effect against all cancer cell lines tested, was active against gram positive bacteria, and showed noteworthy radical scavenging activity. From: Mothana, R. A. A., Gruenert, R., Bednarski, P. J., & Lindequist, U. (2009). Evaluation of the in vitro anticancer, antimicrobial and antioxidant activities of some Yemeni plants used in folk medicine. Die Pharmazie-An International Journal of Pharmaceutical Sciences, 64(4), 260-268.
Althaea officinalis (marshmallow) and Matricaria recutita (German chamomile) had bactericide and bacteriostatic effects against tested bacteria. From: Zarei, B., Saifi, T., Fazeli, A., Khodadadi, E., & Namavar, A. (2013). Evaluation of Antibacterial effects of marshmallow (Althaea officinalis) On four strains of bacteria. International Journal of Agriculture and Crop Sciences, 5(14), 1571.
Essential oil from angelica root had strong antibacterial activity against Staphylococcus aureus and Escherichia coli. From: Aćimović, M. G., Pavlović, S. Đ., Varga, A. O., Filipović, V. M., Cvetković, M. T., Stanković, J. M., & Čabarkapa, I. S. (2017). Chemical composition and antibacterial activity of Angelica archangelica root essential oil. Natural product communications, 12(2), 1934578X1701200216.
The following plant extracts were effective to treat skin infection from S. aureus bacteria: Lonicera alpigena (alpine honeysuckle), Castanea sativa (sweet chestnut), Juglans regia (walnut), Ballota nigra (black horehound), Rosmarinus officinalis (rosemary),Leopoldia comosa (hyacinth), Malva sylvestris (mallow), Cyclamen hederifolium (cyclamen), Rosa canina (dog rose), and Rubus ulmifolius (blackberry). Quave, C. L., Plano, L. R., Pantuso, T., & Bennett, B. C. (2008). Effects of extracts from Italian medicinal plants on planktonic growth, biofilm formation and adherence of methicillin-resistant Staphylococcus aureus. Journal of ethnopharmacology, 118(3), 418-428.
Lemongrass, palmarosa, lavender and rose scented geranium showed in vitro activity against pathogenic vaginal microorganisms. From: Schwiertz, A., Duttke, C., Hild, J., & Mueller, H. J. (2006). In vitro activity of essential oils on microorganisms isolated from vaginal infections. International Journal of Aromatherapy, 16(3), 169-174.
Antibacterial activity against gram positive species was demonstrated by rosemary. From: Pintore, G., Usai, M., Bradesi, P., Juliano, C., Boatto, G., Tomi, F., … & Casanova, J. (2002). Chemical composition and antimicrobial activity of Rosmarinus officinalis L. oils from Sardinia and Corsica. Flavour and Fragrance Journal, 17(1), 15-19.
Aloe gel showed antimicrobial activity, especially against gram-negative bacteria and resistant strains of A. niger. From: Cock, I. E. (2008). Antimicrobial activity of Aloe barbadensis Miller leaf gel components. The Internet Journal of Microbiology, 4(2), 17.
Aloe plant extracts showed antimicrobial activity against a variety of tested pathogenic bacteria and fungi. From: Arunkumar, S., & Muthuselvam, M. (2009). Analysis of phytochemical constituents and antimicrobial activities of Aloe vera L. against clinical pathogens. World Journal of Agricultural Sciences, 5(5), 572-576.
Aloe gel was active against S. flexneri and S. pyogenes. From: Ferro, V. A., Bradbury, F., Cameron, P., Shakir, E., Rahman, S. R., & Stimson, W. H. (2003). In vitro susceptibilities of Shigella flexneri and Streptococcus pyogenes to inner gel of Aloe barbadensis Miller. Antimicrobial agents and chemotherapy, 47(3), 1137-1139.
Rosemary showed activity against oral bacteria in vitro. From: Silva, M. D. S. A., Silva, M. A. R., Higino, J. S., Pereira, M. S. V., & Carvalho, A. D. A. (2008). In vitro antimicrobial activity and anti-adherence of Rosmarinus officinalis Linn. against oral planktonic bacteria. Revista Brasileira de Farmacognosia, 18(2), 236-240.
Rose, geranium, lavender and rosemary oils were the most potent QS inhibitors, destabilize bacterial communities studied. From: Szabó, M. Á., Varga, G. Z., Hohmann, J., Schelz, Z., Szegedi, E., Amaral, L., & Molnár, J. (2010). Inhibition of quorum‐sensing signals by essential oils. Phytotherapy research, 24(5), 782-786.
Essential oils of Eucalyptus camaldulensis and Mentha spicata significantly retard dental biofilm formation. From: Rasooli, I., Shayegh, S., & Astaneh, S. D. A. (2009). The effect of Mentha spicata and Eucalyptus camaldulensis essential oils on dental biofilm. International journal of dental hygiene, 7(3), 196-203.
Tea tree oil and its components, 1,8-cineole, terpinen-4-ol, and α-terpineol demonstrated activity against Staphylococcus aureus. From: Carson, C. F., Mee, B. J., & Riley, T. V. (2002). Mechanism of action of Melaleuca alternifolia (tea tree) oil on Staphylococcus aureus determined by time-kill, lysis, leakage, and salt tolerance assays and electron microscopy. Antimicrobial agents and chemotherapy, 46(6), 1914-1920.
Tea tree has shown activity against the following bacteria: Acinetobacter baumannii, Actinomyces viscosus, Actinomyces spp., Bacillus cereus, Bacteroides spp., Corynebacterium sp., Enterococcus faecalis, E. faecium, Escherichia coli, Fusobacterium nuicleatujm, Klebsiella pneumoniae, Lactobacillus sppl, Micrococcus luteus, Peptostreptococcus anaerobius, Porphyromonas endodentalis, P. gingivalis, Prevotella spp., P. intermedia, Propionibacterium acnes, Proteus vulgaris, Pseudomonas aeruginosa, Staphylococcus aureus, S. epidermidis, S. hominis, S. pyogenes, and Veillonella spp. From:Carson, C. F., Hammer, K. A., & Riley, T. V. (2006). Melaleuca alternifolia (tea tree) oil: a review of antimicrobial and other medicinal properties. Clinical microbiology reviews, 19(1), 50-62.
This study described the antibacterial activity of tea tree oil and terpinen-4-ol against Staphylococcus aureus. From: Cuaron, J. A., Dulal, S., Song, Y., Singh, A. K., Montelongo, C. E., Yu, W., … & Gustafson, J. E. (2013). Tea Tree Oil‐Induced Transcriptional Alterations in Staphylococcus aureus. Phytotherapy Research, 27(3), 390-396.
A preparation with tea tree was effective and safe in treating skin lesions of MRSA. From: Dryden, M. S., Dailly, S., & Crouch, M. (2004). A randomized, controlled trial of tea tree topical preparations versus a standard topical regimen for the clearance of MRSA colonization. Journal of Hospital Infection, 56(4), 283-286.
A variety of oral bacteria were affected by tea tree. From: Hammer, K. A., Dry, L., Johnson, M., Michalak, E. M., Carson, C. F., & Riley, T. V. (2003). Susceptibility of oral bacteria to Melaleuca alternifolia (tea tree) oil in vitro. Oral microbiology and immunology, 18(6), 389-392.
Manuka and tea tree oil demonstrated the most antibacterial activity of oils tested. From: Harkenthal, M., Reichling, J., Geiss, H. K., & Saller, R. (1999). Comparative study on the in vitro antibacterial activity of Australian tea tree oil, cajuput oil, niaouli oil, manuka oil, kanuka oil, and eucalyptus oil. Die Pharmazie, 54(6), 460-463.
Constituents of licorice produced significant antimicrobial activity in vitro. From: Mitscher, L. A., Park, Y. H., Clark, D., & Beal, J. L. (1979). Antimicrobial agents from higher plants. Antimicrobial isoflavanoids and related substances from Glycyrrhiza glabra L. var. typica. Journal of natural products, 43(2), 259-269.
Licorice produced antimycobacterial activity and its glabridin constituent was active against gram positive and gram negative bacteria and Mycobacterium tuberculosis. Gupta, V. K., Fatima, A., Faridi, U., Negi, A. S., Shanker, K., Kumar, J. K., … & Darokar, M. P. (2008). Antimicrobial potential of Glycyrrhiza glabra roots. Journal of Ethnopharmacology, 116(2), 377-380.
Extracts of raspberry, strawberry, cranberry, elderberry, blueberry, and bilberry inhibited Helicobacter pylori in vitro. From: Chatterjee, A., Yasmin, T., Bagchi, D., & Stohs, S. J. (2004). Inhibition of Helicobacter pylori in vitro by various berry extracts, with enhanced susceptibility to clarithromycin. Molecular and cellular biochemistry, 265(1), 19-26.
Mullein plant extract showed antibacterial activity to a variety of tested bacteria. From: Turker, A. U., & Camper, N. D. (2002). Biological activity of common mullein, a medicinal plant. Journal of ethnopharmacology, 82(2), 117-125.
A lactone from the roots of Verbascum undulatum (mullein) exhibited antibacterial activity. From: Magiatis, P., Spanakis, D., Mitaku, S., Tsitsa, E., Mentis, A., & Harvala, C. (2001). Verbalactone, a New Macrocyclic Dimer Lactone from the Roots of Verbascum undulatum with Antibacterial Activity. Journal of natural products, 64(8), 1093-1094.
Parsley and cilantro demonstrated antioxidant and antibacterial activity in vitro. From: Wong, P. Y., & Kitts, D. D. (2006). Studies on the dual antioxidant and antibacterial properties of parsley (Petroselinum crispum) and cilantro (Coriandrum sativum) extracts. Food chemistry, 97(3), 505-515.
Parsley was antibacterial against multiple tested pathogens. From: Seyyednejad, S. M., Maleki, S., Damabi, N. M., & Motamedi, H. (2008). Antibacterial activity of Prunus mahaleb and Parsley (Petroselinum crispum) against some pathogen. Asian J Biol Sci, 1, 51-5.
Manuka and kanuka essential oils showed antibacterial, antifungal, anti-inflammatory activity in vitro, and may be effective against human infectious microorganisms. From: Chen, C. C., Yan, S. H., Yen, M. Y., Wu, P. F., Liao, W. T., Huang, T. S., … & Wang, H. M. D. (2016). Investigations of kanuka and manuka essential oils for in vitro treatment of disease and cellular inflammation caused by infectious microorganisms. Journal of Microbiology, Immunology and Infection, 49(1), 104-111.
Extracts from the leaves of Coleus forskohlii (coleus), Pogostemon patchouli (patchouli) and Tecoma stans showed broad spectrum antibacterial activity. From: Senthilkumar, C. S., Kumar, M. S., & Pandian, M. R. (2010). In Vitro Antibacterial activity of crude leaf extracts from tecoma stans (L) Juss. et Kunth, Coleus Forskohlii and Pogostemon Patchouli against human pathogenic bacteria. International Journal of PharmTech Research, 2(1), 438-442.
The essential oil of Lippia sidoides (verbena), and its major components thymol and carvacrol exhibited potent antimicrobial activity against oral bacteria in vitro. From:Botelho, M. A., Nogueira, N. A. P., Bastos, G. M., Fonseca, S. G. C., Lemos, T. L. G., Matos, F. J. A., … & Brito, G. A. C. (2007). Antimicrobial activity of the essential oil from Lippia sidoides, carvacrol and thymol against oral pathogens. Brazilian Journal of Medical and Biological Research, 40(3), 349-356.
Diphenyliodonium chloride (DIC) and thymol reduce the growth and survivability of Campylobacter species in vitro.From: Anderson, R. C., Krueger, N. A., Byrd, J. A., Harvey, R. B., Callaway, T. R., Edrington, T. S., & Nisbet, D. J. (2009). Effects of thymol and diphenyliodonium chloride against Campylobacter spp. during pure and mixed culture in vitro. Journal of applied microbiology, 107(4), 1258-1268.
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.
The study demonstrated the gram positive and gram negative antibacterial activities of thymol, carvacrol, p-cymene, and γ-terpinene against Staphylococcus aureus and Escherichia coli. From: Cristani, M., D’Arrigo, M., Mandalari, G., Castelli, F., Sarpietro, M. G., Micieli, D., … & Trombetta, D. (2007). Interaction of four monoterpenes contained in essential oils with model membranes: implications for their antibacterial activity. Journal of Agricultural and Food Chemistry, 55(15), 6300-6308.
Thymus caramanicus composed of carvacrol (68.9%), p-cymene (6.0%), thymol (5.3%), gamma-terpinene (4.6%) and borneol (4.0%), showed strong activity against Helicobacter pylori bacteria. From: Eftekhar, F., Nariman, F., Yousefzadi, M., Hadiand, J., & Ebrahimi, S. N. (2009). Anti-Helicobacter pylori activity and essential oil composition of Thymus caramanicus from Iran. Natural product communications, 4(8), 1139-1142.
Achillea millefolium and three other Achillea species showed in vitro antimicrobial activity against tested bacteria, including Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, Pseudomonas aueruginosa, and Salmonella enteritidis. The four species showed antifungal activity against Aspergillus niger and Candida albicans. From: Stojanović, G., Radulović, N., Hashimoto, T., & Palić, R. (2005). In vitro antimicrobial activity of extracts of four Achillea species: The composition of Achillea clavennae L.(Asteraceae) extract. Journal of ethnopharmacology, 101(1), 185-190.
Tea tree oil was effective against a broad spectrum of skin bacteria in vitro. Singh, B. R., Vadhana, P., Bhardwaj, M., Vinodh Kumar, O. R., & Sinha, D. K. (2016). Comparative Antimicrobial Activity of Tea Tree Oil (Melaleuca Oil) and Common Topical Antimicrobials against Bacteria Associated With Wound and Topical Infections. Pharm. Anal. Acta, 7, 513.
Isolated constituents including alantolactone and isoalantolactone from the root extracts of elecampane (Inula helenium) along with epoxyalantolactone and encelin from sweet coneflower (Rudbeckia subtomentosa) demonstrated antimycobacterial against tuberculosis. From: Cantrell, C. L., Abate, L., Fronczek, F. R., Franzblau, S. G., Quijano, L., & Fischer, N. H. (1999). Antimycobacterial eudesmanolides from Inula helenium and Rudbeckia subtomentosa. Planta medica, 65(04), 351-355.
Dried root extract from Inula helenium showed gram positive, gram negative and anticandida activity in vitro, and potentially attributable to the sesquiterpenoid lactone constituents. From: Deriu, A., Zanetti, S., Sechi, L. A., Marongiu, B., Piras, A., Porcedda, S., & Tuveri, E. (2008). Antimicrobial activity of Inula helenium L. essential oil against Gram-positive and Gram-negative bacteria and Candida spp. International Journal of Antimicrobial Agents, 31(6), 588-590.
Inula lelenium and its sesquiterpene lactones showed antistaphylococcal activityin vitro, with membrane-damaging effects. From: Stojanović-Radić, Z., Čomić, L., Radulović, N., Blagojević, P., Denić, M., Miltojević, A., … & Mihajilov-Krstev, T. (2012). Antistaphylococcal activity of Inula helenium L. root essential oil: eudesmane sesquiterpene lactones induce cell membrane damage. European journal of clinical microbiology & infectious diseases, 31(6), 1015-1025.
Hops showed in vitro activity agains bacteria that cause body odor and reduced underarm odor in a clinical evaluation. From: Dumas, E. R., Michaud, A. E., Bergeron, C., Lafrance, J. L., Mortillo, S., & Gafner, S. (2009). Deodorant effects of a supercritical hops extract: antibacterial activity against Corynebacterium xerosis and Staphylococcus epidermidis and efficacy testing of a hops/zinc ricinoleate stick in humans through the sensory evaluation of axillary deodorancy. Journal of cosmetic dermatology, 8(3), 197-204.
Ashwagandha plant root and leaves possessed strong antibacterial activity against a range of bacteria in vitro. From: Owais, M., Sharad, K. S., Shehbaz, A., & Saleemuddin, M. (2005). Antibacterial efficacy of Withania somnifera (ashwagandha) an indigenous medicinal plant against experimental murine salmonellosis. Phytomedicine, 12(3), 229-235.
Leaves from ajowan demonstrated antibacterial activity in vitro against gram negeative bacterial. From: Sayeed, M., Patchigalla, J. R. P., Oggu, R., Srinivas, R. R. P., Pajjuru, S. N., Bakshi, V., & Boggula, N. (2018). Anti Bacterial and Phytochemical Screening of Trachyspermum Ammi–An In Vitro Approach. Research Journal of Pharmacy and Medical Sciences (IRJPMS), 1(4), 40-45.
Antibacterial and antifungal activity of noni was demonstrated in vitro against multiple test organisms. From: Jayaraman, S. K., Manoharan, M. S., & Illanchezian, S. (2008). Antibacterial, antifungal and tumor cell suppression potential of Morinda citrifolia fruit extracts. International journal of integrative biology, 3(1), 44-49.
Bergamot and its linalool constituent were most effective against bacteria that can cause food poisoning. From: Fisher, K., & Phillips, C. A. (2006). The effect of lemon, orange and bergamot essential oils and their components on the survival of Campylobacter jejuni, Escherichia coli O157, Listeria monocytogenes, Bacillus cereus and Staphylococcus aureus in vitro and in food systems. Journal of Applied Microbiology, 101(6), 1232-1240.
Multiple varieties of geranium species were tested in vitro and showed antibacterial activity. Tested species included: Staphylococcus aureus, Proteus vulgaris, Bacillus cereus and Staphylococcus Epidermidis. From:Lis‐Balchin, M., Buchbauer, G., Ribisch, K., & Wenger, M. T. (1998). Comparative antibacterial effects of novel Pelargonium essential oils and solvent extracts. Letters in Applied Microbiology, 27(3), 135-141.
Root extracts from two Pelargonium species were antibacterial and antifungal against tested pathogenic microbes. From:Mativandlela, S. P. N., Lall, N., & Meyer, J. J. M. (2006). Antibacterial, antifungal and antitubercular activity of (the roots of) Pelargonium reniforme (CURT) and Pelargonium sidoides (DC)(Geraniaceae) root extracts. South African Journal of Botany, 72(2), 232-237.
Antimicrobial activity of myrrh against gram negative bacteria was demonstrated in vitro. From: Chandrasekharnath, N., Mahlakshmi, Y. V., Jayalakshmi, L., Venkanna, B., & Uma, A. (2013). Screening and isolation of bioactive factors from Commiphora myrrha and evaluation of their antimicrobial activity. International Journal of Engineering Research and Applications, 3(2), 1291-1294.
Orange extracts were antibacterial against Campylobacter jejuni, Campylobacter coli, and Arcobacter spp. From: Nannapaneni, R., Chalova, V. I., Crandall, P. G., Ricke, S. C., Johnson, M. G., & O’Bryan, C. A. (2009). Campylobacter and Arcobacter species sensitivity to commercial orange oil fractions. International journal of food microbiology, 129(1), 43-49.
Orange, grapefruit, mandarin, and tangerine essential oils demonstrated antioxidant and antimicrobial actions in vitro. From: Javed, S., Javaid, A., Nawaz, S., Saeed, M. K., Mahmood, Z., Siddiqui, S. Z., & Ahmad, R. (2014). Phytochemistry, GC-MS analysis, antioxidant and antimicrobial potential of essential oil from five citrus species. Journal of Agricultural Science, 6(3), 201.
Patchouli, caraway, and geranium showed antibacterial action against S. aureus isolated from skin lessions of infected people. From: Kwiatkowski, P., Mnichowska-Polanowska, M., Pruss, A., Dzięcioł, M., & Masiuk, H. (2017). Experimental Paper. Activity of essential oils against Staphylococcus aureus strains isolated from skin lesions in the course of staphylococcal skin infections. Herba Polonica, 63(1), 43-52.
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.
Jasminum sambac showed antioxidant, antimicrobial, and antibacterial activity in vitro. From: Abdoul-Latif, F., Edou, P., Eba, F., Mohamed, N., Ali, A., Djama, S., … & Dicko, M. (2010). Antimicrobial and antioxidant activities of essential oil and methanol extract of Jasminum sambac from Djibouti. African Journal of Plant Science, 4(3), 38-43.
Bay, cinnamon, grapefruit, lemongrass, thyme, clary sage, wintergreen, clove, allspice, and camphor essential oils showed varying degrees of inhibition against MRSA and MSSA bacterial samples from hospital patients. From: Sharma, P. U. J. A., Mack, J. P., & Rojtman, A. (2013). Ten highly effective essential oils inhibit growth of methicillin resistant staphylococcus aureus (MRSA) and methicillin sensitive staphylococcus aureus (MSSA). Int. J. Pharm. Pharmacol, 5(1), 52-54.
Roman chamomile extracts and essential oil were effective in vitro against bacterial strains that cause oral gingivitis and periodontitis. From: Saderi, H., Owlia, P., Hosseini, A., & Semiyari, H. (2003, February). Antimicrobial effects of chamomile extract and essential oil on clinically isolated Porphyromonas gingivalis from periodontitis. In III WOCMAP Congress on Medicinal and Aromatic Plants-Volume 6: Traditional Medicine and Nutraceuticals 680 (pp. 145-146).
Cypress extracts were antibacterial in vitro against the following: Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae and Salmonella typhimurium.From: Chaudhary, H. J., Shahid, W., Bano, A., Ullah, F., Munis, F., Fahad, S., & Ahmad, I. (2012). In vitro analysis of Cupressus sempervirens L. plant extracts antibaterial activity. Journal of Medicinal Plants Research, 6(2), 273-276.
Extracts and essential oils from Cupressus sempervirens were antibacterial in vitro against food spoilage pathogens. From: Selim, S. A., Adam, M. E., Hassan, S. M., & Albalawi, A. R. (2014). Chemical composition, antimicrobial and antibiofilm activity of the essential oil and methanol extract of the Mediterranean cypress (Cupressus sempervirens L.). BMC complementary and alternative medicine, 14(1), 179.
Australian tea tree oil, cajuput, niaouli, lema, kanuka, and manuka showed antimicrobial activities against Staphylococcus aureus. From: Christoph, F., Stahl-Biskup, E., & Kaulfers, P. M. (2001). Death kinetics of Staphylococcus aureus exposed to commercial tea tree oils sl. Journal of Essential Oil Research, 13(2), 98-102.
Various extracts of grapefruit peel were antimicrobial, antibacterial, and antifungal against tested pathogenic disease organisms. From: Okunowo, W. O., Oyedeji, O., Afolabi, L. O., & Matanmi, E. (2013). Essential oil of grape fruit (Citrus paradisi) peels and its antimicrobial activities. American Journal of Plant Sciences, 4(07), 1.
Against the oral bacteria: Streptococcus mutans, Porphyromonas gingivalis, and Lactobacillus rhamnosus, the 13 most effective essential oils were: myrrh, ginger, basil, carrot seed, tea tree, patchouli, ylang ylang, cypress, lemongrass, cinnamon, peppermint, lavender, and eucalyptus. From: Park, C., & Yoon, H. (2018). Antimicrobial Activity of Essential Oil against Oral Strain. International Journal of Clinical Preventive Dentistry, 14(4), 216-221.