Efektivitas Antibakteri Ekstrak Kulit Rambutan (Nephelium lappaceum) terhadap Bakteri Streptococcus mutans berdasarkan KHM dan KBM

Abstract

Streptococcus mutans is a facultative anaerobic gram-positive bacterium that is the most dominant microorganism involved in the development of dental caries. S. mutans is capable of metabolizing carbohydrates into acidic products that can demineralize enamel, leading to caries formation. Inhibiting the growth of S. mutans represents a key preventive approach to reducing caries incidence. Rambutan peel is known to contain various secondary metabolites with antibacterial properties. This study aims to determine the antibacterial effectiveness of rambutan peel extract (Nephelium lappaceum) against Streptococcus mutans. This study is a laboratory experimental research using a post-test only with controlled group design. The samples used were Streptococcus mutans bacteria and rambutan peel extract (Nephelium lappaceum), tested at 8 different concentrations and 2 control groups, each with 3 replications. The Minimum Inhibitory Concentration (MIC) was determined using the Kirby-Bauer disk diffusion method, while the Minimum Bactericidal Concentration (MBC) was determined through streaking based on the MIC results. Data analysis for determining MIC and MBC values was conducted using the Kruskal-Wallis test (p<0.05), followed by the Mann Whitney test. The findings of this study indicate that rambutan peel (N. lappaceum) extract possesses antibacterial activity against Streptococcus mutans. Growth inhibition was observed starting at a concentration of 3.125%, producing a mean inhibition zone of 7.40 ± 0.19 mm, and increased up to 80%, with a mean inhibition zone of 18.34 ± iv 0.12 mm. Bactericidal activity was achieved at concentrations of 70% and 80%, both demonstrating 100% reduction of S. mutans. The study concludes that the MIC value was determined at a concentration of 3.125%, categorized as having moderate inhibitory activity. The MBC value was established at a concentration of 70%, as it was able to reduce the initial bacterial colony count by ≥99,9%. Therefore, the effective concentration of rambutan peel extract that exhibits both inhibitory and bactericidal effects, and thus has potential as an alternative antiseptic mouthwash, is 70%.