Clove Essential Oil

Clove Essential Oil – Uses And Benefits
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Clove Essential Oil – General Description

Cloves refer to the unopened, nail-shaped pink flower buds derived from the evergreen tree native to Indonesia, Syzygium aromaticum. They turn brown upon drying, and due to their sweet, rather penetrating flavor, ground cloves are occasionally used in baking where they confer a distinctive warm, sweet, and aromatic taste to, say, ginger bread and pumpkin pie and in various Asian cuisines as flavoring to meat, curries, and marinades. ^[1]

Clove essential oil can be extracted from the flower buds, leaves, or twigs of S. aromaticum through steam distillation. It appears light golden yellow in color; has a medium to strong aroma, middle perfumery note, and medium consistency; and blends well with other spice oils as well as citronella, grapefruit, lemon, orange, peppermint, rosemary, and rose essential oils. ^[2] Its aroma is described as rich, spicy, heart-warming, and revitalizing. ^[3]

Clove Essential Oil – Uses and Reported Benefits

Clove essential oil finds utility not only in perfumery and flavoring (as a savoring agent) but also in dentistry and alternative medicine owing to the broad spectrum of biological activities it is claimed to exert, including antioxidant, antifungal, antibacterial, and antiviral. ^[4] Being a local anesthetic, it can be used to relieve minor pains and aches, especially toothache, and, when infused, it helps remedy flu and colds since it is an immune booster and anti-inflammatory agent. ^[2] When massaged over the abdomen, this essential oil can relieve indigestion and nausea and can warm the body. ^[3]

Clove Essential Oil – Contraindications and Safety

Possible skin sensitivity upon the use of clove essential oil can happen to allergic individuals, and since it can interact with blood-thinning medications, it is best to check with a health care provider prior to use. Furthermore, pregnant and lactating women are advised to refrain from using clove essential oil or to consult their physicians first.

Clove Essential Oil – Scientific Studies And Research

There has been a substantial amount of research data pointing to the effectiveness of clove essential oil against various disease-causing microorganisms and parasites, such as bacteria, fungi, and herpes simplex and hepatitis C viruses. ^[4] A research team from Northeast Forestry University, China, for example, had evaluated the antimicrobial activity of clove and rosemary essential oils and found both oils to be significantly bactericidal and fungicidal against Staphylococcus epidermidis, Escherichia coli, and Candida albicans, with clove essential oil having a minimum inhibitory concentration (MIC) of 0.062% to 0.500% (v/v). ^[5] Clove essential oil is mostly used as an antiseptic in cases of oral infections because of its efficient ability to inhibit Gram-negative and Gram-positive bacteria as well as yeast, as evidenced by the study of Nuñez and Aquino (2012). ^[6] Dorman and Deans (2000) similarly reported the antibacterial activity of clove essential oil against 25 different genera of bacteria, most of which are animal and plant pathogens and food poisoning and spoilage bacteria. ^[7] Clove essential oil’s secret to its potent antibacterial effect lies on its phenolic compound content, principally eugenol, which denatures some proteins of bacteria and yeasts and negatively alters the cell membrane permeability of these microorganisms by reacting with the membrane phospholipids. ^[6]

As mentioned earlier, one of clove essential oil’s biological treasures is its ability to effectively deter the growth of fungi and viruses. In the study of Pinto, Vale-Silva, Cavaleiro, and Salgueiro (2009), researchers from the University of Porto, Portugal, clove essential oil exhibited powerful antifungal activity against clinically relevant fungi, including fluconazole-resistant strains of Candida and Aspergillus. As illustrated in this study, clove essential oil’s fungicidal effect can be attributed to the resultant extensive lesion of the cell membranes of yeasts and filamentous fungi upon treatment with concentrations over the MIC. Moreover, clove essential oil and eugenol, one of its key components, reduce the amount of ergosterol present, a specific fungal cell membrane component, and completely inhibit the formation of germ tube in C. albicans. ^[8] Researchers from the Department of Virology, Toyama Medical and Pharmaceutical University, Japan, had evaluated the antiviral activity of ten selected herbal extracts against herpes simplex virus type 1 (HSV-1) and found the clove extract as among those that displayed stronger anti-HSV-1 activity in vitro in combination with acyclovir, a drug used to treat viral infections such as genital herpes, shingles, and chickenpox. In this Japanese study, clove extract orally administered in non-toxic amounts equivalent to human dose significantly minimized the development of skin lesions and prolonged the mean survival times of infected mice, remarkably reducing the virus yield in the brains of mice. ^[9]

Clove essential oil demonstrates considerable antioxidant activities as well, as observed in the study of Jirovetz et al. (2006) where it exhibited scavenging activity against the 2,2-diphenyl-1-picryl hydracyl (DPPH) radical, produced a noteworthy inhibitory effect against hydroxyl radicals, and acted as an iron chelator. ^[10] Additionally, clove essential oil was found to inhibit in vitro the production of pro-inflammatory cytokines such as interleukins 1 and 6 by macrophages in treated mice. ^[11] These data altogether suggest the potential of clove essential oil as an antioxidant and anti-inflammatory agent.

There is growing interest also on the promising potential of cloves as an anticancer agent due to a substantial amount of data indicating their ability to inhibit carcinogenesis (i.e., the development of cancer). The study findings of Banerjee and Das (2005), for example, have pointed out the dose-dependent chemoprotective action of clove infusion against skin papilloma formation; orally administered to mice, the clove infusion delayed the development of papillomas and reduced the overall number of papillomas in papilloma-bearing mice in this study. ^[12] Miyazawa and Hisama (2003) were able to isolate the suppressive compounds responsible for the anticancer or antimutagenic activity of clove buds, which were identified as dehydrodieugenol and trans-coniferyl aldehyde. Both of these compounds suppressed the expression of umu gene in Salmonella typhimurium TA1535/pSK1002 treated with different mutagens and reduced the mutagenic potential of chemicals used in the study. ^[13]

Clove Essential Oil – Molecular Components and Chemistry

Clove essential oil owes much of its beneficial health properties to the phenylpropanoids such as carvacrol, thymol, eugenol, and cinnamaldehyde that it contains. ^[4] In a 2006 Austrian study, clove essential oil was proved to contain also beta-caryophyllene (17.4%), alpha-humulene (2.1%), and eugenyl acetate (1.2%) as the main components. ^[10]