Comparative Evaluation of Antimicrobial Activity between Clove and Ginger Extracts against Streptococcus mutans: An...

Dental caries, primarily caused by Streptococcus mutans, is a prevalent oral health issue. Natural compounds such as clove and ginger exhibit antibacterial properties. The plant-derived compounds release phytochemicals, which aid in controlling the risk of the development of dental caries. This study aims to evaluate the efficacy of clove and ginger extracts against S. mutans in vitro, potentially offering new insights into alternative antimicrobial agents for caries prevention.

To compare and assess the antimicrobial activity of the spice extract-clove (Syzygium aromaticum) and ginger (Zingiber officinale) against S. mutans.

Approximately, 10 gm of ginger and clove powder was mixed with 10 mL of 70% ethanol. S. mutans [American Type Culture Collection (ATCC) 25175] were subcultured in brain heart infusion (BHI) broth and incubated at 37°C for 18-24 hours. The antimicrobial activity of ginger and clove extracts was evaluated using the microbroth dilution method in sterile 96-well microtiter plates.

Growth of S. mutans was observed for two concentrations of clove (3.125 and 1.6%) and one concentration of ginger (1.6%). The median value for clove was 24 [Interquartile range (IQR): 20.25-29.25] and for ginger was 11.5 (IQR: 8.75-12.75). The comparison between ginger and clove at 1.6% concentration yielded a Z-value of -1.826 with a p-value of 0.068 (p > 0.05). While the lower median CFU count suggests ginger may have stronger antimicrobial activity, the difference was not statistically significant, indicating comparable efficacy of both extracts at this concentration.

Both ginger and clove extracts demonstrated antimicrobial activity against S. mutans. Ginger maintained complete growth inhibition up to 3.125% concentration, whereas clove showed bacterial growth at 3.125%. At an identical 1.6% concentration, ginger demonstrated a lower median CFU count (11.5, IQR: 8.75 - 12.75) compared to clove (24, IQR: 20.25 - 29.25), indicating stronger antimicrobial activity. However, this difference was not statistically significant (p = 0.068), suggesting comparable efficacy under the tested conditions. Both extracts show potential as natural antimicrobial agents for dental caries prevention.

Rajkumar M, Ganesh A, Vignesh KC, et al. Comparative Evaluation of Antimicrobial Activity between Clove and Ginger Extracts against Streptococcus mutans: An In Vitro Study. Int J Clin Pediatr Dent 2025;18(12):1489-1492.