Rosmarinic acid – plant polyphenol with antimicrobial and antibiofilm potential

Abstract

Increasing antimicrobial resistance accompanied by range of side effects linked to antibiotics overuse are urging the demand for the novel antimicrobials with the ones obtained from natural sources considered as an appealing alternative. Rosmarinic acid is naturally occurring plant polyphenol. This study aimed to enlighten its potential role as inhibitor of planktonic and biofilm microorganism growth, along with its antifungal mechanisms. In this study, rosmarinic acid has shown promising anticandidal (MIC 0.1-0.2 mg/mL) (Table 1) and antibacterial (MIC 0.05->0.8 mg/mL) activity. To some extent rosmarinic acid was able to reduce attachment of fungal cells to abiotic surface, first stage in biofilm formation process, and eradicate preformed biofilms. Rosmarinic acid antifungal mode of action involves interference with membrane integrity, but not binding to membrane lipid, ergosterol, or reduction in protease production; while its antibiofilm activity is moderately attributed to decrease in exopolysaccharide production. Considering its wide antimicrobial and antibiofilm capacity rosmarinic acid could be further examined as antimicrobial agent along with range of medicinal plants with rosmarinic acid as the dominant compound.