Comparison of the Antibacterial Effect of the Essence and Hydroalcoholic Extract of Celery (<i>Apium graveolens</i>) Against <i>Streptococcus mutans</i> in Vitro

Abstract

Background: Streptococcus mutans is the microorganism associated with dental caries, a process involving the demineralization of teeth. Apium graveolens Linn. (celery), belonging to the family Apiaceae, is recognized as a medicinal plant. Some secondary metabolites produced by celery act as bioactive compounds with potential antimicrobial effects. Objectives: The present study investigates the antibacterial activity of A. graveolens against S. mutans and compares the antibacterial effects of celery extract and essence against S. mutans in vitro, aiming to provide herbal prophylactic agents. Methods: In this in-vitro study, the antibacterial activity of celery (essence) was assessed after preparing celery seed essence and celery ethanolic extract with six different concentrations. The antibacterial effects against S. mutans were evaluated using three methods: The agar well diffusion method, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). Mean comparisons were performed using the Kruskal-Wallis H test and Dunn’s post-hoc test for pairwise comparisons. Data analysis was conducted with SPSS version 22. Results: The hydroalcoholic extract exhibited almost similar antibacterial activity across all evaluated concentrations, while the essence of celery seeds inhibited S. mutans proliferation only at a concentration of 100 µg/mL, with an inhibition zone of 21 mm. The MIC and MBC of the three evaluated groups (hydroalcoholic extract of celery leaves and stems, essence of celery seeds, and penicillin) showed significant differences (P-value = 0.005). The MIC and MBC of the second group were lower than those of the first group but higher than penicillin. The MIC and MBC values of celery extract and celery seed essence against S. mutans were 3.9 ± 1.56 µg/mL and 100 µg/mL, respectively. Conclusions: The ethanolic extract and essence of celery exhibited notable antibacterial properties against Streptococcus mutans.