Enhanced Extraction of Antishigellosis Compounds from <I>Ficus elastica</I> Leaves: A Response Surface Methodology Approach

The leaves of Ficus elastica Roxb. ex Hornem exhibit strong antishigellosis activity against Shigella dysenteriae. This study investigated the effects of varying reflux conditions, including temperature and time, using response surface methodology (RSM) to optimize the extraction of antishigellosis compounds. Reflux conditions for F. elastica leaf extraction were designed using the Central Composite Design (CCD) method under RSM. A total of nine variations in reflux conditions were generated, with temperature ranging from 20°C to 80°C and time ranging from 1 to 3 h. The agar diffusion method was employed to evaluate the antibacterial activity of the extracts against S. dysenteriae ATCC 13313, with inhibition zone diameters used as the response variable. The interaction between temperature and time was analyzed using ANOVA. Optimization using RSM demonstrated that under optimal conditions (50°C and 2 h), the extraction yield increased significantly by 165.65%, achieving a yield of 16.23% (w/w) compared to 6.11% (w/w) under standard conditions. Furthermore, the antibacterial activity against Shigella spp. improved by 54.55%, with the inhibition zone diameter increasing from 11 mm under normal conditions to 17 mm under optimal conditions. This study highlights the importance of determining precise reflux parameters tailored to the sample and target compounds to enhance extraction efficiency and bioactivity.