In Vitro Antibacterial Activity of Selected Herbal Extracts on Streptococcus mutans

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Jitrada Wannachot
Sakulrat Rattanakiat


Introduction: Dental caries is an infectious disease associated with numerous microorganisms, mainly Streptococcus mutans. Since consumers mostly have a concern of trustworthy and least harmful products for health care, health industries, including dental care business, have contributed huge effort on production of natural substances. The aim of this study was to investigate the inhibitory effect against S. mutans in vitro of the 95% ethanol extracts from fi ve herbs, Psidium guajava L., Momordica cochinch inensis  preng.,Glycyrrhiza glabra L., Syzygium aromaticum L. and Piper retrofractum Vahl. Methods:
Antimicrobial activity was evaluated using disc diffusion and broth dilution method. The combination
inhibitory effects of extracts against S. mutans were also determined using checkerboard assay.
Results: Some extracts showed activity against S. mutans. The extract of S. aromaticum showed the
largest mean diameter of inhibition zone (16.7±0.5 mm) while the extract of G. glabra was the most
effective with the lowest minimum inhibitory concentration (MIC) of 0.195 mg/mL and minimum
bactericidal concentration (MBC) of 3.125 mg/mL. A combined extract of S. aromaticum and P. guajava
showed a synergistic effect in inhibiting the growth of S. mutans. Conclusion: The results showed that
these herbal extracts provide the potential candidate for developing an oral antimicrobial agent to
control or prevent dental diseases associated with oral pathogenic bacteria like S. mutans.


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Anderson DM, Smith WG. The antitussive activityof glycyrrhetinic acid and its derivatives. J Pharm Pharmacol 1961; 13: 396-404.

Aneja KR, Joshi R. Antimicrobial activity of Syzygium aromaticum and its bud oil against dental caries causing microorganisms. Ethnobot Leaflets 2010; 14: 960-975.

Badria FA, Zidan OA. Natural products for dental caries prevention. J Med Food 2004; 7(3): 381-384.

Cai L. Compounds from Syzygium aromaticumpossessing growth inhibitory activity against oral pathogens. J Nat Prod 1996; 59(10): 987-990.

Clinical and Laboratory Standards Institute. Performance standards for antimicrobial disk susceptibility test. Approved standardM02-A11. 11th ed. CLSI, Wayne, PA. 2012, 32: 1.

Chaiya A, Saraya S, Chuakul W, et al. Screening for dental caries: preventive activities of medicinal plants against Streptococcus mutans. Mu J pharm 2013; 40(1): 9-17.

Eliopoulos GM, Moellering Jr. RC, editors. Antimicrobial combinations. In: Antibiotics in laboratory medicine. 4th ed. Baltimore (MD): William & Wilkins; 1996. 330-338.

Fathilah AR. Piper betle L. and Psidium guajava L. in oral health maintenance. J Med Plants Res 2011; 5(2): 156-163.

Fathilah AR, Rahim ZH, Othman Y. Bacterio-static effect of Piper betle and Psidium guajava extracts on dental plaque bacteria. Pak J Biol Sci 2009; 12(6): 518-521.

Fathilah AR, Yusoff M, Rahim HA. The effect of Psidium guajava and Piper betle extracts on the morphology of dental plaque bac-teria. Pak J Med Sci 2009; 25(6): 928-933.

Geetha RV, Anitha R. In vitro evaluation of antibacterial activity of ethanolic root extract of Glycyrrhiza glabra on oral microbes. Int J Drug Dev & Res 2012; 4(4): 161-165.

Hasan S, Singh K, Danisuddin M, et al. Inhibition of major virulence pathways of Strepto-coccus mutans by quercitrin and deoxynojirimycin: a synergistic approach of infection control. PLoS ONE 2014; 9(3): e91736.

Hemaiswarya S, Doble M. Synergistic interaction of eugenol with antibiotics against gram-negative bacteria. Phytomedicine2009; 16: 997–1005.

Jordan C, Leblanc DJ. Infl uences of orthodontic appliances on oral populations of mutans streptococci. Oral Microbiol Immun 2002; 17(2): 65-71.

Khan M, Siddiqui M. Antimicrobial activity of piper fruits. Nat Prod Radi 2007; 6(2): 111-113.

Kim KJ, Lee MS, Jo K, et al. Piperidine alkaloids from Piper retrofractum Vahl. protect against high-fat diet-induced obesity by regulating lipid metabolism and activating AMP-activated protein kinase. Biochem Biophys Res Commun 2011; 411(1): 219-225.

Kubola J, Siriamornpun S. Phytochemicals and antioxidant activity of different fruit fractions (peel, pulp, aril and seed) of Thai M. cochinchinensis (Momordica cochinchinensis Spreng). Food Chem2011; 127: 1138–1145.

Kumar A, Dora J. Review on Glycyrrhiza glabra (G. glabra). J Pharm SciInnovat 2012; 1: 1-4.

Limsong J, Benjavongkulchai E, KuvatanasuchatiJ. Inhibitory effect of some herbal extracts on adherence of Streptococcus mutans. J Ethnopharmacol 2004; 92(2-3): 281-289.

Loesche WJ. Role of Streptococcus mutans in human dental decay. Microbiol Rev 1986; 50(4): 353-380.

Moody J. Synergism testing: broth microdilution checkerboard and broth macrodilution methods. In: Isenber HD, editor. Clinical microbiology procedures handbook. 2ndedition. Volume 2. Washington DC: American Society for Microbiology Press; 2004.1-23.

Nantachit K, Tuchinda P.” Antimicrobial activity of hexane and dichloromethane extracts from Momordica cochinchinensis (Lour.) Spreng leaves”. Thai Pharm Health Sci J 2009; 4(1): 15-20.

Prabu GR, Gnanamani A, Sadulla S. Guaijaverin – a plant flavonoid as potential antiplaque agent against Streptococcus mutans. J Appl Microbiol 2006; 101: 487–495.

Razak FA, Othman RY, Rahim ZH. The effect of Piper betle and Psidium guajava extracts on the cell-surface hydrophobicity of selected early settlers of dental plaque. J Oral Sci 2006; 48(2): 71-75.

Razak FA, Rahim ZHA. The anti-adherence effect of Piper betle and Psidium guajavaextracts on the adhesion of early settlers in dental plaque to saliva-coated glass surfaces. J oral sci 2003; 45(4): 201-206.

Saraya S, Kanta J, Sarisuta N, et al. Development of guava extract chewable tablets for anticariogenic activity against Streptococcus mutans. Mu J Pharm 2008; 35(1-4): 18-23.

Sela MN, Steinberg D, Segal R. Inhibition of the activity of glucosyltransferase from Streptococcus mutans by glycyrrhizin. Oral Microbiol Immunol 1987; 2: 125–128.

Shuxu J, Li Y, Xue C, et al. The effect of eugenol on the cariogenic properties of Streptococcus mutans and dental caries development in rats. Exp Ther Med 2013; 5: 1667-1670.

Sutabhaha B, Khantawa B. Antibacterial and antifungal activities Fak Khaao leaf extract. Faculty of Associated Medical Sciences 2011; 44(1): 31-37.

Tewtrakul S, Hase K, Kadota S, et al. Fruit oil composition of Piper chaba Hunt. P. longum L. J Essent 2000; 2: 603-608.

Vuong LT, Franke AA, Custer LJ, et al. Momordica cochinchinensis Spreng (M. cochinchinensis) fruit carotenoids reevaluated. J Food Compos Anal 2006; 19: 664–668.