The Essential Properties: Cloves
by the Doctor Matteo Politi
Pharmacological activity
In addition to its antibacterial, antioxidant, antifungal and antiviral activity, clove essential oil has anti-inflammatory, cytotoxic, insect repellent and anesthetic properties.1
Antibacterial activity
The antibacterial activity of clove essential oil has been demonstrated against several pathogenic bacteria including Campylobacter jejuni, Salmonella enteritidis, Escherichia coli And Staphylococcus aureus.8–10 The highest antibacterial activity was observed against five strains of S. epidermidis (reference strains CIP106510, E13, S27, S23 and S38) and is thought to be mainly due to the presence of eugenol.1
Antifungal activity
The fungicidal activity of clove essential oil has been reported on several food-borne fungal species.11, and it was observed that it inhibited the growth of Aspergillus niger.3
Antiviral activity
The antiviral activity of pure eugenol and clove essential oil against herpes simplex virus has been verified.12,13 For antiviral activity against HSV-1 and HSV-2, the inhibitory concentration values of 50% were 25.6μg/mL and 16.2μg/mL, respectively.14
Anesthetic activity
Eugenol has found widespread use in a wide range of applications as a local anesthetic, especially in the field of dentistry.15 The local anesthetic and analgesic effects of clove essential oil and its possible mechanisms of action in acute corneal pain in rats have been described by Khalilzadeh et al.16
Phytochemical profile
The main compounds of the essential oil obtained from cloves (Syzygium aromaticum (L.) Merr. & LMPerry) belong to the class of phenylpropanoids and the major compound is generally considered to be eugenol, followed by β-caryophyllene and smaller amounts of other components such as benzyl alcohol, but the proportions vary widely.1 For example, Prashar et al.2 found the eugenol content at 78%, with 13% of β-caryophyllene, while Pawar and Thaker3 verified that the eugenol content was 47.64%, with a concentration of benzyl alcohol at 34.10%. The factors that can influence the chemical composition depend for example on the place of origin and the material used for the extraction of the essential oil, generally the dried flower buds, but the leaves are also used which in any case have a similar phytochemical profile. Numerous works on the subject can be found in the literature.4–7
Bibliography
1. Chaieb K, Hajlaoui H, Zmantar T, et al. The chemical composition and biological activity of clove essential oil, Eugenia caryophyllata (Syzigium aromaticum L. Myrtaceae): A short review. Phyther Res. 2007;21:501–506. doi:10.1002/ptr.2124
2. Prashar A, Locke IC, Evans CS. Cytotoxicity of clove (Syzygium aromaticum) oil and its major components to human skin cells. Cell Prolife. 2006;39:241–248. doi:10.1111/j.1365-2184.2006.00384.x
3. Pawar VC, Thaker VS. In vitro efficacy of 75 essential oils against Aspergillus niger. Mycoses. 2006;49:316 –323. doi:10.1111/j.1439-0507.2006.01241.x
4. Alma MH, Ertaş M, Nitz S, Kollmannsberger H. Chemical composition and content of essential oil from the bud of cultivated Turkish clove (Syzygium aromaticum L.). BioResources. 2007;2(2):265-269. doi:10.15376/biores.2.2.265-269
5. Srivastava AK, Srivastava SK, Syamsundar K V. Bud and leaf essential oil composition of Syzygium aromaticum from India and Madagascar. Flavour Fragrance J. 2005;20:51–53. doi:10.1002/ffj.1364
6. Pino JA, Marbot R, Agüero J, Fuentes V. Essential oil from buds and leaves of clove (Syzygium aromaticum (L.) Merr. et Perry) grown in Cuba. J Essent Oil Res. 2001;13:278-279. doi:10.1080/10412905.2001.9699693
7. Gaylor R, Michel J, Thierry D, Panja R, Fanja F, Pascal D. Bud, leaf and stem essential oil composition of Syzygium aromaticum from Madagascar, Indonesia and Zanzibar. Int J Basic Appl Sci. 2014;3(3):224-233. doi:10.14419/ijbas.v3i3.2473
8. Friedman M, Henika PR, Mandrell RE. Bactericidal activities of plant essential oils and some of their isolated constituents against Campylobacter jejuni, Escherichia coli, Listeria monocytogenes, and Salmonella enterica. J Food Prot. 2002;65:1545–1560. doi:10.4315/0362-028X-65.10.1545
9. Burt SA, Reinders RD. Antibacterial activity of selected plant essential oils against Escherichia coil O157:H7. Lett Appl Microbiol. 2003;36(3):162-167. doi:10.1046/j.1472-765X.2003.01285.x
10. Larhsini M, Oumoulid L, Lazrek HB, et al. Antibacterial activity of some Moroccan medicinal plants. Phyther Res. 2001;15:250–252. doi:10.1002/ptr.815
11. López P, Sánchez C, Batlle R, Nerín C. Solid- and vapor-phase antimicrobial activities of six essential oils: Susceptibility of selected foodborne bacterial and fungal strains. J Agric Food Chem. 2005;96:716 –724. doi:10.1021/jf050709v
12. Tragoolpua Y, Jatisatienr A. Anti-herpes simplex virus activities of Eugenia caryophyllus (Spreng.) Bullock & SG Harrison and essential oil, eugenol. Phyther Res. 2007;21:1153–1158. doi:10.1002/ptr.2226
13. Benencia F, Courges MC. In vitro and in vivo activity of eugenol on human herpesvirus. Phyther Res. 2000;14:495–500. doi:10.1002/1099-1573(200011)14:7<495::AID-PTR650>3.0.CO;2-8
14. Pramod K, Ansari SH, Ali J. Eugenol: A natural compound with versatile pharmacological actions. Nat Prod Common. 2010;5(12):1999-2006. doi:10.1177/1934578×1000501236
15. Chung G, Oh SB. Eugenol as Local Anesthetic. In: Ramawat K, Mérillon J, eds. Natural Products. Springer; 2013.
16. Khalilzadeh E, Hazrati R, Saiah GV. Effects of topical and systemic administration of Eugenia caryophyllata buds essential oil on corneal anesthesia and analgesia. Res Pharm Sci. 2016;11(4):293-302. doi:10.4103/1735-5362.189297