Abstract

Biofilm is a community of cells attached to either a biotic or abiotic surface enclosed in a complex exopolymeric substance (EPS). Biofilms allow micro–organisms to trap nutrients and withstand hostile environmental conditions by Quorum sensing (QS). Several serious infections and disease are reported as a result of biofilm. This study aimed to evaluate the efficacy of natural compounds Curcumin and Negundoside on the biofilm producing property of Streptococcus mutans. Samples were collected from patients having oral infection and 30 isolates were identified as S. mutans and screened for biofilm formation by using microtiter plate method. Strongest biofilm producer SM03 was used for minimum inhibitory concentration and minimum biofilm inhibitory concentration. Subsequently this concentration used against each of strong biofilm producer isolates at 492<0.5 optical density (OD). The 30 isolates screened for biofilm formation, 18 isolates showed strong biofilm formation, 09 isolates showed moderate formation and 03 isolates showed poor/non biofilm formation. The MIC of Curcumin for the strongest biofilm producer SM03 was, 0.63±0.02 whereas that of Negundoside was 0.48± 0.02 and minimum biofilm inhibition concentration of Curcumin was 0.0570±0.03 and Negundoside 0.0417±0.03 which was lower than the Curcumin. The MBIC of both compounds significantly inhibited biofilm formation of all the 18 strong biofilm-forming isolates. The results of this study demonstrated significant antibiofilm effect of the natural compound Curcumin and Negundoside which contribute towards the development of database for novel drug candidates for treating oral infection caused by S. mutans.

Keywords

S. mutans, biofilm, natrual compound, curcumin, negundoside, EPS, exopolymeric substance, QS, quorum sensing, AI, autoinducers, BHI, brain heart infusion, MSA, mutant sanguis agar