Antibiofilm activity of Clitoria ternatea flowers anthocyanin fraction against biofilm-forming oral bacteria

This study investigated the antibiofilm effects of Clitoria ternatea flowers anthocyanin fraction (AF) on Streptococcus mutans, Actinomyces viscosus and Aggregatibacter actinomycetemcomitans. AF was obtained using column chromatography, and liquid chromatography-mass spectrometry was employed for its characterization and identification. The crystal violet assay and scanning electron microscopy analysis revealed significant inhibition of early biofilm formation and destruction of preformed biofilms after AF treatment (0.94-15 mg mL-1). Anti-adhesion assay on acrylic teeth demonstrated that AF effectively hampered sucrose dependent and independent attachment. Importantly, growth curve and pH drop assays showed that AF inhibited pH reduction for all bacteria tested without hindering bacterial growth. Furthermore, the tetrazolium-based cytotoxicity assay indicated no toxicity towards normal human gingival fibroblasts (HGF-1) at 0.78-12.5 mg mL-1. These findings suggest C. ternatea anthocyanins are promising antibiofilm agents for oral biofilm control, acting during both initial formation and on mature biofilms.