Antibacterial effects of Trigonella foenum-graceum L. and Kellusia odoratissima Mozaff versus 0.2% chlorhexidine on Streptococcus mutans count: An in vitro study

Introduction: Tooth decay is a prevalent chronic disease worldwide; preventive care is essential for its management.Despite some side effects, Chlorhexidine mouthwash is the gold standard for controlling plaque and preventing caries.This study evaluates the antibacterial effects of "Trigonella foenum-graceum" L. and "Kellusia odoratissima" Mozaff extracts on "Streptococcus mutans" compared to 0.2% chlorhexidine mouthwash. Materials & Methods:This laboratory study involved preparing herbal extracts of "Trigonella foenum-graceum" L. and "Kellusia odoratissima" Mozaff.The Well Diffusion Agar test measured the inhibition zone diameter at a concentration of 100,000 ppm for the extracts and chlorhexidine mouthwash, with chlorhexidine and distilled water serving as positive and negative controls, respectively.The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined for the extracts and mouthwash.Finally, the "Streptococcus mutans" count was assessed after exposure to the extracts and mouthwash.Data were analyzed using SPSS 26.0, applying the Kruskal-Wallis test for group comparisons and the Mann-Whitney U test for pairwise comparisons. Results:The study reported three key findings.The inhibition zone diameters were 19 mm for chlorhexidine mouthwash, 0 mm for "Trigonella foenum-graceum" L., and 13 mm for "Kellusia odoratissima" Mozaff.MIC values were 6250 ppm for chlorhexidine, >100000 ppm for "Trigonella foenum-graceum", and 50000 ppm for "Kellusia odoratissima", with corresponding MBC values of 12500 ppm, >100000 ppm, and 100000 ppm.Significant differences in bacterial reduction percentages were noted after 30 minutes and 6 hours (both: p<0.001), with chlorhexidine showing the highest efficacy at 30 minutes, while "Kellusia odoratissima" Mozaff had the highest efficacy at 6 hours. Conclusion:This study demonstrated that "Kellusia odoratissima" Mozaff extract has antibacterial effects comparable to chlorhexidine, while "Trigonella foenumgraceum" L. showed limited antibacterial activity against "Streptococcus mutans".