It has been established that berberine has strong antimicrobial effects. Little is known however regarding the antimicrobial activity of berberine against endodontic pathogenic bacteria or its cytotoxicity in human oral tissue cells. The antibacterial properties of berberine were tested against 5 strains of Enterococcus faecalis and type strains of Aggregatibacter actinomycetemcomitans, Prevotella nigrescens, Prevotella intermedia, and Tannerella forsythia, which are involved in endodontic infections. Antimicrobial activity was evaluated through minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) measurements. The viability of normal human gingival fibroblast (NHGF) cells after exposure to berberine was measured using a methyl thiazolyl tetrazolium (MTT) assay. The data showed that berberine has antimicrobial effects against A. actinomycetemcomitans with an MIC and MBC of 12.5 μg/ml and 25 μg/ml, respectively. In the cytotoxicity studies, cell viability was maintained at 66.1% following exposure to 31.3 μg/ml berberine. Overall, these findings suggest that berberine has antimicrobial activity against the tested bacteria. Nevertheless, lower concentrations in combination with other reagents will need to be tested before these in vitro results can be translated to clinical use.

• Dongkyun Lee(Department of Conservative Dentistry, School of Dentistry, Chosun University)
• Min Jung Kim(Korean Collection for Oral Microbiology, Department of Oral Biochemistry, and Oral Biology Research Institute, School of Dentistry, Chosun University)
• Soon-Nang Park(Korean Collection for Oral Microbiology, Department of Oral Biochemistry, and Oral Biology Research Institute, School of Dentistry, Chosun University)
• Yun Kyong Lim(Korean Collection for Oral Microbiology, Department of Oral Biochemistry, and Oral Biology Research Institute, School of Dentistry, Chosun University)
• Jeong-Beom Min(Department of Conservative Dentistry, School of Dentistry, Chosun University)
• Ho-Keel Hwang(Department of Conservative Dentistry, School of Dentistry, Chosun University)
• Joong-Ki Kook(Korean Collection for Oral Microbiology, Department of Oral Biochemistry, and Oral Biology Research Institute, School of Dentistry, Chosun University) Correspondence