<b> Antibacterial and cytotoxic effects of chlorhexidine combined with sodium DNA on oral microorganisms: an <i>in vitro</i> study using </b> <i> <b>Dictyostelium discoideum</b> </i>
Simone Rocco, Adriana Antonina Tempesta, Gaia Vertillo Aluisio, Maria Lina Mezzatesta, Alessandra Romano, Valentina Schiavo, Barbara Pergolizzi, Maria Santagati, Cristina Panuzzo, Gaetano Isola
Abstract
Background Chlorhexidine (CHX) is widely used in oral care for its broad-spectrum antimicrobial activity but can cause significant side effects. Sodium DNA has emerged as a potential adjunct capable of modulating cellular responses.Aim This study assessed whether sodium DNA enhances the antibacterial and antibiofilm activity of 0.20% and 0.12% CHX mouthwashes against Streptococcus mutans and Escherichia coli, and evaluated their effects on the viability and phagocytic activity of Dictyostelium discoideum, a model for mammalian phagocytes.Results All CHX-containing mouthwashes were bactericidal against S.mutans, regardless of sodium DNA, whereas CHX-only formulations were more effective against E.coli in time–kill assays. All formulations inhibited biofilm formation at 50–0.01%. In S. mutans, early biofilms were strongly inhibited (50–0.39%), whereas mature biofilms were less affected. In E. coli, sodium DNA enhanced inhibition of both biofilm formation (50–1.56%) and mature biofilms (50–3.12%). The 0.12% CHX–sodium DNA formulation most effectively modulated D.discoideum viability and phagocytic activity, and metabolomics showed that sodium DNA reduced CHX-induced metabolic stress.Conclusions This study integrates antimicrobial, antibiofilm, cellular, and metabolomic analyses to assess CHX with sodium DNA. Sodium DNA reduces CHX-induced cytotoxicity and metabolic stress while maintaining antimicrobial activity, offering insights for optimizing oral hygiene formulations through combined microbial and host-cell evaluation.