Dual Antioxidant and Antibacterial Activities of Natural Compounds: Evaluating Their Efficacy Against Pathogenic Bacteria

The rise of antibiotic-resistant bacteria presents a significant global health challenge, emphasizing the urgent need for alternative antimicrobial agents. This study investigates the antioxidant and antibacterial properties of several natural organic acids and flavonoids against common bacterial pathogens, including Escherichia coli (ATCC 25222), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), Salmonella enterica (ATCC 13076), and Bacillus subtilis (ATCC 6633). To evaluate antibacterial activity, minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined through microdilution methods. Among the compounds tested, oxalic acid emerged as the most promising antibacterial agent, showing significant activity against Bacillus subtilis (MIC 0.087 μg/μl, MBC 0.35 μg/μl) and Escherichia coli (MIC 22.5 μg/μl, MBC 22.5 μg/μl). Additionally, oxalic acid exhibited potent antibacterial effects against Staphylococcus aureus (MIC 0.70 μg/μl, MBC 1.40 μg/μl) and Salmonella enterica (MIC 0.70 μg/μl, MBC 5.62 μg/μl). Succinic acid demonstrated moderate efficacy against Pseudomonas aeruginosa (MIC 0.18 μg/μl, MBC 0.73 μg/μl), while gallic acid proved particularly effective against Salmonella enterica (MIC 0.36 μg/μl, MBC 2.89 μg/μl). Other compounds tested, including quercetin, vanillin, ferulic acid, and ascorbic acid, showed varied antibacterial profiles.

In addition to antibacterial activity, the antioxidant properties of these compounds were evaluated, revealing a significant correlation between their antioxidant capacity and antimicrobial effects. This suggests that the antioxidant potential of these compounds may contribute to their antibacterial activity. Overall, the results highlight the potential of natural compounds as alternative antimicrobial agents, with a dual action as both antioxidants and bactericidal agents. These findings support the further exploration of natural products for developing new antimicrobial strategies to combat resistant bacterial infections.