[Study of antibacterial effect of Galla Chinensis on the bacteria biofilm in chemostat].
OBJECTIVE
To compare the antibacterial effect of Galla Chinensis with that of chlorhexidine by means of chemostat and provide experimental foundation for caries prevention with Chinese medicine instead of chemicals in future.


METHODS
A multispecies consortium biofilm (BF) model was construted in the chemostat. The growth-inhibition on bacterial biofilm coated on HA was investigated by means of the colony-forming units (CFU). Acid-inhibition was inspected by continual pH-recording in the flow cells. And the profile on the biofilm treated by both experimental medicines was observed with the scanning electromicroscopy (SEM).


RESULTS
Both of the experimental medicines could inhibit the growth of the BF bacteria. And Galla Chinensis had no obvious influence on the ecological composing of the BF bacteria. Both of the experimental medicines could inhibit the acid producion of experimental bacteria. But the final pH of Galla Chinensis was lower than that of chlorhexidine. A typical biofilm formed on HA was observed by SEM. Both of Galla chinensis and chlorhexidine could inhibit the production of extracellular matrix and make the BF profile on the surface of the HA clearer and simpler.


CONCLUSIONS
Galla Chinensis had definite antibacterial effect. No obvious difference is found between Galla Chinensis (4 g x L(-1)) and chlorhexidine (0.5 g x L(-1)). Therefore, it is possible for Chinese medicine to gradually replace the chemical medicine in clinic and it will give a new choice for caries prevention.
Lh
Hong
H
West China College Stomatology of Sichuan University, Chengdu 610041, China.
Li
Ji-yao
JY
Zhu
Bing
B
Zhou
Xue-dong
XD
D000190:Actinomyces / Q000187:drug effects / Q000254:growth & development; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000891:Anti-Infective Agents, Local / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002710:Chlorhexidine / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007313:Insecta / Q000737:chemistry; D008419:Materia Medica / Q000302:isolation & purification / Q000494:pharmacology*; D013295:Streptococcus mutans / Q000187:drug effects / Q000254:growth & development; D013298:Streptococcus sanguis / Q000187:drug effects / Q000254:growth & development
D000900:Anti-Bacterial Agents; D000891:Anti-Infective Agents, Local; D008419:Materia Medica; D002710:Chlorhexidine