Coptidis rhizoma inhibits growth and proteases of oral bacteria.
OBJECTIVE
The aim of this study was to investigate the antibacterial effect of Coptidis Rhizoma (CR), a traditional medicinal plant, on oral bacteria.


METHODS
CR extract was prepared by boiling CR in water for 2 h. Alkaloids contained in CR extract were assayed by high performance liquid chromatography (HPLC). Antibacterial activity of CR extract was estimated from the lowest concentration that did not permit bacterial growth (minimum inhibitory concentration, MIC) and the concentrations that inhibited 50% of bacterial proteolytic activity (IC50).


RESULTS
CR extract inhibited the growth of Actinomyces naeslundii, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens and Actinobacillus actinomycetemcomitans at MIC of 0.031-0.25 mg ml(-1), whereas it had less inhibitory effect (MIC: 0.5-2 mg ml(-1)) on the growth of Streptococcus and Lactobacillus. The major active component of CR extract was berberine (Ber), an alkaloid, and its inhibiting specificity to bacterial growth was similar to that of CR extract. CR extract and Ber were bacteriostatic at the MICs against most of the bacteria, and bacteriocidal at the concentrations higher than the MICs. Ber inhibited the activities of collagenase from P. gingivalis and A. actinomycetemcomitans.


CONCLUSIONS
CR extract and Ber had an inhibitory effect on periodontopathogenic bacteria. These results suggest the possibility of their clinical application for the treatment of periodontal diseases.
Hu
J P
JP
Department of Oral Biochemistry, Tohoku University School of Dentistry, Sendai, Japan.
Takahashi
N
N
Yamada
T
T
D000190:Actinomyces / Q000187:drug effects; D016976:Aggregatibacter actinomycetemcomitans / Q000187:drug effects; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D001599:Berberine / Q000031:analogs & derivatives* / Q000494:pharmacology; D001600:Berberine Alkaloids / Q000494:pharmacology; D000089042:Coptis chinensis; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D006801:Humans; D007778:Lactobacillus / Q000187:drug effects; D007928:Lethal Dose 50; D061965:Matrix Metalloproteinase Inhibitors; D008826:Microbial Sensitivity Tests; D009055:Mouth / Q000382:microbiology*; D018713:Prevotella intermedia / Q000187:drug effects; D045242:Prevotella nigrescens / Q000187:drug effects; D011480:Protease Inhibitors / Q000494:pharmacology*; D029626:Ranunculaceae; D013291:Streptococcus / Q000187:drug effects
D000890:Anti-Infective Agents; D001600:Berberine Alkaloids; D004365:Drugs, Chinese Herbal; D061965:Matrix Metalloproteinase Inhibitors; D011480:Protease Inhibitors; C034384:coptisine; D001599:Berberine; C107393:Coptidis rhizoma extract; C005413:palmatine