IADR Abstract Archives
Endocannabinoids Show Anti-Bacterial and Anti-Biofilm Activities Against Streptococcus Mutans
Objectives: Streptococcus mutans is a common cariogenic bacterium in the oral cavity involved in plaque formation and dental caries. Novel strategies are required to overcome the biofilm and cariogenic properties of these bacteria. Here, we studied the ability of three naturally occurring bioactive lipids (Anandamide (AEA), 2-arachidonylglycerol (2-AG) and N-arachidonoyl serine (AraS)) in preventing planktonic growth and biofilm formation of S. mutans.
Methods: The planktonic growth in the presence of the compounds was followed by measuring the optical density. The effect on membrane potential was measured on flow cytometry using DiOC2(3). Effect on membrane permeability was studied by SYTO 9/PI staining on flow cytometry. Changes in pH were measured at various time points. The biofilm mass was measured by crystal violet staining, MTT metabolic assay, ATP content, and SYTO9/PI staining.
Results: All three bioactive lipids showed dose-dependent inhibition of S. mutans planktonic growth with a minimum inhibitory concentration of 12.5µg/ml for AEA and 2-AG and 25µg/ml for AraS. These compounds also prevented the pH drop caused by S. mutans, which went along with the growth inhibitory activity. AEA caused an immediate membrane hyperpolarization of the S. mutans at doses above 12.5µg/ml AEA. At doses above 12.5µg/ml, AEA caused membrane permeation after 2 h resulting in increased PI uptake with concomitant reduced SYTO 9 staining. Importantly, these agents inhibited biofilm formation by S. mutans in a dose-dependent manner with a biofilm minimum inhibitory concentration of 50µg/ml for AEA and 2-AG and 25µg/ml for AraS.
Conclusions: Our study shows that these three bioactive lipids can inhibit both planktonic growth and biofilm formation by the cariogenic S. mutans. Thus, these compounds can serve as a natural means to improve oral hygiene.
Methods: The planktonic growth in the presence of the compounds was followed by measuring the optical density. The effect on membrane potential was measured on flow cytometry using DiOC2(3). Effect on membrane permeability was studied by SYTO 9/PI staining on flow cytometry. Changes in pH were measured at various time points. The biofilm mass was measured by crystal violet staining, MTT metabolic assay, ATP content, and SYTO9/PI staining.
Results: All three bioactive lipids showed dose-dependent inhibition of S. mutans planktonic growth with a minimum inhibitory concentration of 12.5µg/ml for AEA and 2-AG and 25µg/ml for AraS. These compounds also prevented the pH drop caused by S. mutans, which went along with the growth inhibitory activity. AEA caused an immediate membrane hyperpolarization of the S. mutans at doses above 12.5µg/ml AEA. At doses above 12.5µg/ml, AEA caused membrane permeation after 2 h resulting in increased PI uptake with concomitant reduced SYTO 9 staining. Importantly, these agents inhibited biofilm formation by S. mutans in a dose-dependent manner with a biofilm minimum inhibitory concentration of 50µg/ml for AEA and 2-AG and 25µg/ml for AraS.
Conclusions: Our study shows that these three bioactive lipids can inhibit both planktonic growth and biofilm formation by the cariogenic S. mutans. Thus, these compounds can serve as a natural means to improve oral hygiene.