In vitro anti-bacterial activity of diosgenin on Porphyromonas gingivalis and Prevotella intermedia

Diosgenin (Dios), a natural steroidal sapogenin, is a bioactive compound extracted from dietary fenugreek seeds. It has a wide range of applications, exhibiting anti-oxidant, anti-inflammatory and anti-cancer activities. However, whether the extracts have beneficial effects on periodontal pathogens has so far remained elusive. The aim of the present study was to investigate the anti-bacterial effects of Dios on Porphyromonas gingivalis (P. gingivalis) and Prevotella intermedia (P. intermedia) in vitro. The anti-microbial effect of Dios on P. gingivalis and P. intermedia was assessed by a direct contact test (DCT) and the Cell Counting Kit (CCK)-8 assay at 60, 90 and 120 min. In addition, counting of colony-forming units (CFU) and live/dead cell staining were used to evaluate the anti-bacterial effects. The results of the DCT and CCK-8 assays indicated that Dios had beneficial dose-dependent inhibitory effects on P. gingivalis and P. intermedia. The CFU counting results also indicated that Dios had dose-dependent anti-bacterial effects on P. gingivalis and P. intermedia. Of note, Dios had significant anti-bacterial effects on the biofilms of P. gingivalis and P. intermedia in vitro as visualized by the live/dead cell staining method. In conclusion, the present results demonstrated that Dios had a marked anti-bacterial activity against P. gingivalis and P. intermedia in vitro, both in suspension and on biofilms. The present study highlighted the potential applications of Dios as a novel natural agent to prevent and treat periodontitis through its anti-bacterial effects.