Antimicrobial potential of boron-containing compounds: Antibacterial, antifungal, and antimycobacterial activities

The global rise in multidrug-resistant (MDR) pathogens necessitates the discovery of new antimicrobial agents. Boron-containing compounds (BCCs) are increasingly studied for their broad-spectrum biological activities. The current study aimed to investigate the antibacterial, antifungal, and antimycobacterial activities of four different BCCs (Zinc borate, boric acid, borax, and Etidot-67) by determining their minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentrations (MBC/MFC). For the first time, the antimycobacterial activity of BCCs was evaluated against both reference and clinical strains. All tested compounds exhibited notable antimicrobial activity. Among them, boric acid and zinc borate showed strong antibacterial effects, particularly against Staphylococcus aureus and Salmonella typhimurium at 64 μg/mL. Borax displayed the most potent antimycobacterial activity, with a MIC of 64 μg/mL against Mycobacterium tuberculosis H37Ra (MT-H37Ra). Antifungal tests revealed boric acid to be highly effective against Candida albicans and Saccharomyces cerevisiae, with MIC values as low as 8-16 μg/ mL. These findings suggest that BCCs, especially borax and boric acid, may serve as viable candidates for the development of alternative antimicrobial therapies. However, further in vivo studies, toxicological assessments, and mechanistic investigations are necessary to support their clinical application.