ANTIBIOFILM ACTIVITY OF ANTIMICROBIAL PHOTODYNAMIC THERAPY WITH TURMERIC EXTRACT AGAINST ENTEROCOCCUS FAECALIS

Abstract: Objective: To assess the antibiofilm activity of antimicrobial photodynamic therapy (APDT) with different concentrations of ethanolic extract of Curcuma longa L. against Enterococcus faecalis. Materials and methods: Ethanolic extract of Curcuma longa L. was used as the photosensitizer, activated with a light-emitting diode (LED). A total of 33 wells containing Enterococcus faecalis biofilms were divided into 11 groups: ethanolic extract of Curcuma longa L. at the concentration range of 2000 μg/mL to 7.81 μg/mL, 2% chlorhexidine (positive control) and biofilms without treatment (negative control). The crystal violet assay was used for biofilm quantification. Data were analyzed by ANOVA followed by Tukey’s Post Hoc Test (p<0.05). Results: All treatments with APDT using ethanolic extract of Curcuma longa L., except 2000 μg/mL and 1000 μg/mL, showed a statistically significant reduction of biofilm formation, compared to the negative control group (p<0.05). The lowest mean absorbance values (OD) were observed in the groups treated with ethanolic extract of Curcuma longa L. at concentrations of 62.5 and 31.25 μg/mL (68% and 70% biofilm reduction, respectively). The mean absorbance values obtained with the concentration range of ethanolic extract from 62.5 to 7.81 μg/mL were significantly lower than the one obtained with the concentration of 1000 μg/mL (p<0.05), while there were no significant differences when comparing them with the value obtained with 2% chlorhexidine. Conclusions: There is a statistically significant difference in the antibiofilm activity of antimicrobial photodynamic therapy with ethanolic extract of Curcuma longa L. at different concentrations against Enterococcus faecalis. APDT with ethanolic extract of Curcuma longa L. at low concentrations showed significant antibiofilm activity against E. faecalis in vitro.