Transcriptomic and in vitro analysis of red pitahaya betacyanin fraction as a natural anti-biofilm agent against oral Streptococcus mutans

Dental plaque biofilms, primarily formed by Streptococcus mutans, contribute significantly to oral diseases, necessitating effective anti-biofilm strategies. This study investigates the anti-biofilm potential of red pitahaya betacyanin fraction (BF) using transcriptomic analysis and an in vitro denture plaque model. Stringent differential gene expression analysis (p < 0.01, log₂ fold change > ± 2) revealed that BF significantly downregulates genes involved in sucrose metabolism, energy production, and cell wall biosynthesis, impairing bacterial adhesion and biofilm integrity. Notably, the suppression of pfkB (phosphofructokinase) and fructose-specific PTS transporters revealed BF's ability to disrupt carbohydrate metabolism, while the downregulation of ciaR/ciaH two-component system impairs stress response and biofilm formation. Simultaneous upregulation of genes linked to glycolysis, arginine metabolism, and oxidative stress defence suggest an adaptive response to BF-induced stress. Gene ontology enrichment and protein-protein interaction analyses further confirmed that BF disrupts multiple bacterial pathways, including ATP synthesis, quorum sensing, and cell wall integrity. In an in vitro denture biofilm model, BF treatment resulted in a 79% reduction in plaque accumulation, demonstrating efficacy comparable to chlorhexidine while avoiding adverse effects such as staining. These findings underscore the potential of BF as a natural anti-biofilm agent with broad-spectrum inhibitory effects on S. mutans. Given its efficacy and safety profile, BF holds promise for incorporation into oral hygiene formulations as a novel therapeutic for biofilm-associated dental diseases.