Author(s): Muhammad Faiq Luthfan, Helmia Farida, Winarto and Tri Nur Kristina

Abstract: Bitter melon with phytochemical contents has been proven to contain anti-microbial activity. However, previous studies only used diffusion method with uncertain breakpoint for the inhibition zone diameter (IZD) produced. The aim of this research was to examine the effect of Bitter Melon Extract (BME) on S. aureus and S. pyogenes by the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) methods as well as IZD. The method of this research was experimental research with post-test only control group design was carried out using 6 groups consisted of 1 positive control (K+) as the indicator of visual clarity, 4 different concentrations of BME (100%, 50%, 25% and 12,5%) inoculated with bacteria and 1 negative control (K-). MIC was determined by comparing the turbidity of inoculated tubes with K+. MBC was evaluated by plating the culture on agar plate to examine whether sterile growth produced. This study showed that MIC of BME against S. aureus and S. pyogenes are 50% and 25%. MBC study showed bacterial growth. IZD of S. aureus and S. pyogenes for BME to be claimed as sensitive were 12 mm and 9 mm. The higher the concentration of BME, the wider the IZD.