Cytotoxicity and antimicrobial action of selected phytochemicals against planktonic and sessile Streptococcus mutans

Abstract

Dental caries remains the most prevalent and costly oral infectiousdisease worldwide, encouraging the search for new and more effective antimicrobials.Therefore, the aim of this work was to study the antimicrobial action of selected phytochemicals (eugenol, citronellol, sabinene hydrate, trans-cinnamaldehyde, terpineol andcinnamic acid) against Streptococcus mutans in planktonic and biofilm states as well asthe cytotoxicity of these compounds.Methods. The antibacterial activity of the selected compounds was evaluated by thedetermination of the minimal bactericidal concentration. The resazurin assay was usedto assess the metabolic activity of sessile S. mutans. The cytotoxicity was determinedusing a fibroblast cell line.Results. Among the tested phytochemicals, citronellol, cinnamic acid and transcinnamaldehyde were the most effective against both planktonic and sessile S. mutans,an effect apparently related to their hydrophobic character. Additionally, these threecompounds did not compromise fibroblasts cell viability.Discussion. Citronellol, cinnamic acid and trans-cinnamaldehyde demonstrated significant antimicrobial activity and low cytotoxicity proposing their potential as a novelgroup of therapeutic compounds to control oral infectious diseases. Moreover, theireffects are particularly relevant when benchmarked against eugenol, a phytochemicalcommonly used for prosthodontic applications in dentistry.