Antibacterial Activity of Red Dragon Fruit (Hylocereus Polyrhizuz) On Streptococcus Mutans

Abstract

Objective: The objective of the study was to evaluate the antibacterial activity of the red dragon fruit extract (Hylocereuspolyrhizus) to the growth of Streptococcus mutans (S. mutans). Methods: Red dragon fruit peel and pulp extract were obtained by maceration using ethanol 96%. Pathological isolates S. mutans was obtained from Department of Microbiology, Faculty of Dentistry, University of Jember. The inhibition testing method has used well diffusion method. The treatment is started by giving red dragon fruit peel and pulp extract concentration of 100%, 50%, 0.2% chlorhexidine and aquadest sterile in each of the wells, then incubated for 24 h and was measured using a digital caliper. The antibacterial activities were assessed by the presence of inhibition zones after incubating the plates at 37 °C for 24 h. Results: Based on the results of inhibition zone calculation, on average the biggest inhibition zone found in the positive control group(16.84 mm), then followed by peel100% (10.34 mm), peel50%(8.57 mm), pulp100% (6.79 mm), and pulp50%(5.93 mm). The higher concentration on the peel and pulp of the fruit shows the bigger inhibition zone diameter. The Kruskall-Wallis test showed a significant difference (p<0.05) and Mann Whitney test results showed a significant difference between the study group (p<0.05). Conclusion: The red dragon fruit extract (Hylocereuspolyrhizus) showed significant antibacterial activity against S. mutans, and inhibition power ability of fruit peel extract is larger in inhibiting the S. mutans than its pulp ability.