Antibacterial activity of Sonoran propolis and some of its constituents against clinically significant Vibrio species.
The aim of the present study was to evaluate the anti-Vibrio activity of propolis collected from three different areas of the Sonoran Desert in northwestern, Mexico [Pueblo de Alamos (PAP), Ures (UP), and Caborca (CP)]. The anti-Vibrio spp. activity of Sonoran propolis was determined by the broth microdilution method. UP propolis showed the highest antibacterial activity [minimal inhibitory concentration (MIC(50))<50 μg mL(-1)] against Vibrio spp. (UP>CP>PAP). UP propolis significantly inhibited the growth of Vibrio cholerae O1 serotype Inaba (MIC(50)<50 μg mL(-1)), V. cholerae non-O1 (MIC(50)<50 μg mL(-1)), V. vulnificus (MIC(50)<50 μg mL(-1)), and V. cholerae O1 serotype Ogawa (MIC(50) 100 μg mL(-1)), in a concentration-dependent manner. The UP propolis constituents, galangin and caffeic acid phenethyl ester (CAPE), exhibited a potent growth inhibitory activity (MIC(50) 0.05-0.1 mmol l(-1)) against V. cholerae strains (non-O1 and serotype Ogawa). The strong anti-Vibrio activity of Sonoran propolis and some of its chemical constituents (galangin and CAPE) support further studies on the clinical applications of this natural bee product against different Vibrio spp., mainly V. cholerae.