Curcuma caesia Roxb is a rhizomatous herb of the Zingiberaceae family, which is traditionally used in ethnomedicine for treating infections, wounds, inflammation, and respiratory disorders. The present study assessed the antimicrobial activity of successive solvent extracts of C. caesia rhizomes using agar well and disc diffusion assays against Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Candida albicans, and Penicillium chrysogenum. Among the extracts, ethyl acetate exhibited the strongest antimicrobial activity, with ZOI ranging from 4.6 ± 1.15 mm to 19.3 ± 0.57 mm in the well diffusion method and 8.6 ± 0.57 mm to 15.6 ± 0.57 mm in the disc diffusion method, followed by methanol, which showed moderate but consistent inhibition. Acetone and aqueous extracts displayed relatively weak and selective activity, being effective only against a few test organisms. Statistical analysis (ANOVA) confirmed significant differences among extracts (p < 0.05). These findings support the ethnomedicinal claims of C. caesia and highlight the ethyl acetate fraction as a promising candidate for the development of plant-based antimicrobial agents.
