Anti-infective activity of simvastatin against Candida and selected periodontal pathogens – An in vitro study

Background: Statins, in addition to their hypolipidemic action, also show antibacterial and antifungal activity. The present research examines the antimicrobial activity of simvastatin (SMV) against periodontal microorganisms: Prevotella intermedia (Pi), Tannerella forsythia (Tf), Fusobacterium nucleatum (Fn), and Candida tropicalis (Ct). Materials and Methods: SMV was evaluated for minimum inhibitory concentration by microdilution and for antimicrobial susceptibility by agar disc diffusion. The antibiofilm effect of SMV was further compared with chlorhexidine (0.2%) (CHX) at 6 h, 24 h, 48 h, and 72 h. Results: SMV inhibited all three periodontal bacteria at 0.8 μg/ml and inhibited Ct at a minimum concentration of 50 μg/mL. The mean diameter of the zone of inhibition by SMV for Pi, Fn, Tf , and Ct was 13 ± 0.81 mm, 13.33 ± 0.47 mm, 15.33 ± 0.47 mm, and 14 ± 0.81 mm, respectively. SMV showed a peak reduction in colony-forming unit (CFU) counts from baseline (223.42 ± 10.50 CFU/mm) to 6 h (157.25 ± 8.081 CFU/mm), which was subsequently sustained. Compared with SMV, CHX demonstrated a slower but more consistent reduction in CFU counts for up to 72 h. Conclusion: The tested microorganisms were sensitive to SMV. In addition, SMV was as effective as the common antiplaque agent CHX at preventing these organisms and their proliferation in a biofilm environment during the testing periods. The study provides preliminary evidence of the antimicrobial effects of SMV, which warrants further exploration for its dual therapeutic benefits in periodontal applications.