Rosmarinic acid inhibits biofilm formation of Streptococcus mutans

Emerging antimicrobial resistance and adverse effects associated with antimicrobial over use necessitate new antimicrobial therapeutics with natural compounds considered as attractive alternatives to synthetic drugs. Rosmarinic acid is abundant in medicinal plants. The aim of this study was to elucidate its possible role as an inhibitor of Streptococcus mutans biofilm growth. The amount of biofilm formed by S. mutans bacteria was estimated using colorimetric method and optical profilometry. In this study, rosmarinic acid showed significant inhibitory activity at 5 mg/mL concentration on S. mutans biofilm formationin 1% sucrose containing medium. Considering the broad antimicrobial and antibiofilm spectrum of activity, rosmarinic acid can be used as an antimicrobial agent along with a number of medicinal plants containing rosmarinic acid as a dominant compound. However, rosmarinic acid can serveas a basis for the development of antimicrobial and therapeutic and prophylactic drugs used in dental practice.