Pudilan Keyanning mouthwash inhibits dextran-dependent aggregation and biofilm organization of Streptococcus mutans

This research aimed to investigate the inhibitory effects of Pudilan mouthwash (PDL) on Streptococcus mutans (S. mutans) biofilms and identify its chemical components. The impacts of 100% concentrated PDL on S. mutans biofilm were detected by colony-forming unit (CFU) assays, crystal violet staining, confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM) and quantitative real-time PCR (qRT‒PCR). The biocompatibility with human gingival fibroblasts (HGFs) was evaluated by Cell-Counting-Kit-8 (CCK-8) assay. And chemical components were identified by UPLC-HRMS. PBS and 0.12% chlorhexidine were used as negative control and positive control, respectively. Results indicate early 8 h S. mutans biofilms are sensitive to PDL. Additionally, it leads to a decrease in bacterial activities and dextran-dependent aggregation in 24 h S. mutans biofilms. PDL significantly downregulates the gene expression of gtfB/C/D and smc. And 114 components are identified. PDL has an inhibitory effect on S. mutans and favorable biocompatibility. It has potential to be exploited as a novel anti-biofilm agent.