Comparative Evaluation of Combinatory Interaction between Endocannabinoid System Compounds and Poly-L-lysine against Streptococcus mutans Growth and Biofilm Formation

Abstract EN

Endocannabinoid/endocannabinoid-like (EC/EC-like) are natural endogenous compounds which have been found to affect MRSA pathogenicity.

Our previous studies showed that EC/EC-like was able to impair staphylococcal biofilm formation and maintenance as well as to alter biofilm-associated virulence factors.

In the present study, we investigated the combinatory effect of the selected EC/EC-like with a natural antimicrobial agent, poly-L-lysine, on cariogenic bacteria Streptococcus mutans growth and biofilm formation.

Among four tested EC/EC-like, only two, anandamide (AEA) and oleoylethanolamide (OEA), exhibited synergistic combinatory effect with poly-L-lysine against S.

mutans.

We attribute this distinct effect to differences in the fatty acid chain structure of the selected EC/EC-like compounds.

Moreover, AEA exerted a specific antibiofilm mode of action against S.

mutans by effecting total inhibition of biofilm formation while still allowing bacteria viability.

Finally, we postulate that the presence of EC/EC-like and poly-L-lysine could enhance the permeability and efficacy of each other via hydrophobic and electrostatic interactions with the S.

mutans membrane.

In conclusion, we assume that a combination of endogenous natural compounds such as EC/EC-like and poly-L-lysine may benefit oral hygiene by preventing dental plaque.