Journal of Pure and Applied MicrobiologyVol. 8 No. Special Edition Nov. 2014

Antimicrobial Activity of Ethanol Extracts of Xanthium strumarium L. against Oral Microorganisms

Yeon-Hee Kim1, Jeong Hwan Kim2, Hyung-Joo Jin2 and Si Young Lee1*

1Department of Microbiology and Immunology, College of Dentistry, Research Institute of Oral Science and 2Department of Marine Molecular Biotechnology, College of Life Sciences, Gangneung-Wonju National University, Gangneung, 210-702, Korea.

Received on 20 December 2013 and accepted on 03 February 2014

 

ABSTRACT

Xanthium strumarium L. is an annual or a short-lived perennial that is readily found in the fields. In this study, the antimicrobial activity of ethanol extracts of X. strumarium on oral microbial species was examined for possible usage of extracts of X. strumarium in dental care products. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined by a microdilution method in culture medium. The MICs for oral streptococci were between 125 and 500 µg/ml. The MBCs for streptococci were between 250 and 2,000 µg/ml. Actinomyces naeslundii, Actinomyces odontolyticus and Aggregatibacter actinomycetemcomitans showed similar MICs and MBCs as oral streptococcal strains. The MICs were 62.5 and 15.6 µg/ml for Fusobacterium nucleatum and Porphyromonas gingivalis, respectively. In the experiment for examining the effect of concentration of extracts and incubation time on the killing of bacteria, the killing of Streptococcus mutans was dependent on concentration of extracts and incubation time. The treatment of bacteria with extracts changed the cell surface texture of S. mutans and P. gingivalis. The surface of bacteria treated with extracts was rougher than untreated bacteria and small bumps appeared on the surface of both bacteria after treatment with extract. Based on the results of this study, extracts of X. strumarium would be a useful material for the development of antimicrobial agents against oral pathogens.

Keywords : Antibacterial agents; dental plaque; extract; pathogen; Xanthium.