뮤탄스 연쇄상구균에 대한 Ursolic acid와 Betulinic acid의 항균 효과

Abstract

Ursolic acid and betulinic acid are triterpenoid componuds that are widely distribuced in medicinal plants and other plants. The purpose of this study was to determine the antimicrobial activity of ursolic acid and betulinic acid against mutans streptococci. The antimicrobial activity was evaluated by minimal inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time kill curves on mutans streptococci. The cytotoxicity of ursolic acid and betulinic acid on human gingival fibroblasts and human periodontal ligament were tested by metyl thiazolyl tetrazolium (MTT) assay. MIC90 values of ursolic acid for Streptococcus mutans, Streptococcus sobrinus and Streptococcus downei isolated from Korean were 2 ㎍/㎖, 4 ㎍/㎖ and 8 ㎍/㎖, respectively. MBCs values of ursolic acid were 4 ㎍/㎖ against mutans streptococci. But betulinic acid did not demonstrate any antibacterial activity against mutans streptococci. Time kill curves were performed for S. mutans ATCC 25175T, S. sobrinus ATCC 33478T, and S. downei ATCC 33748T in the presence of ursolic acid at their respective MBC. Usrolic acid 2× MBC were bactericidal against S. mutans ATCC 25175T and S. downei ATCC 33748T after 12 h of incubation whereas 4× MBC was bactericidal against S. sobrinus ATCC 33478T. Ursolic acid was no cytotoxic effect on human gingival fibroblasts and human periodontal ligament in the concentration having antimicrobial effect. The results indicate that ursolic acid could be useful in the development of oral hygiene products for the prevention of dental caries.