Phytochemical Screening and Antibacterial Activity of Jatropha multifida L. (Coral Bush) Leaf Extract-Based Soap Against Staphylococcus aureus and Escherichia coli

The development of bio-based hygiene products offers a sustainable approach to managing infectious topical pathogens while reducing dependence on synthetic antimicrobials. This study evaluated the antibacterial efficacy of soap formulated with Jatropha multifida leaf ethanolic extract (25%, 50%, and 75% v/v) against Staphylococcus aureus and Escherichia coli. Antibacterial activity was determined using the Kirby–Bauer disk diffusion method alongside positive and negative controls. All extract-infused soap formulations exhibited distinct, measurable zones of inhibition (ZOI) ranging from 16.33 mm to 17.67 mm for S. aureus and 16.33 mm to 18.00 mm for E. coli, consistently achieving an “Active” qualitative classification. A one-way analysis of variance (ANOVA) demonstrated highly significant differences across the entire dataset (p < 0.001). However, Tukey’s Honestly Significant Difference (HSD) post hoc test revealed no statistically significant differences in antibacterial performance among the 25%, 50%, and 75% concentrations (p > 0.05). This indicates a performance plateau caused by agar diffusion limits or micellar entrapment within the soap base. J. multifida maintains antibacterial integrity within a soap matrix, offering a viable plant-based antiseptic alternative against S. aureus and E. coli. Formulating at a 25% concentration represents the optimal commercial choice, maximizing antimicrobial performance while minimizing raw material costs.