Antimicrobial Activity of Belleric Acid against Pathogenic Microorganisms

The Belleric acid (BA) found in terminalia species (especially terminalia chebula, terminalia bellirica (TB), and terminalia arjuna) is a hydrolyzable tannin with antimicrobial activity and is widely used in folk and herbal medicine systems. It shows potent anti-inflammatory effects by inhibiting NFκB activation, antimicrobial effects, and MAPK phosphorylation. In this study, Terminalia Bellirica (TB) was used as the source of BA. TB is abundantly found in India’s deciduous forests. Studies have shown that extracts of BA exhibit antimicrobial effects against both Gram-positive and Gram-negative bacteria. This study aims to evaluate the antimicrobial activity of BA against Escherichia coli and Bacillus cereus.

BA was tested against E. coli and B. cereus using the minimum inhibition concentration (MIC), fluorescence microscopy, diameter of inhibition zone, nucleic acid leakage, membrane potential, and cell structure morphology.

BA exhibited an MIC of 150 µg/mL. The diameter of the inhibition zone for E. coli was 24.13±0.004 mm, and for B. cereus, it was observed to be 26.12±0.008 mm. BA showed membrane potentials of 308.19±0.013 to 312.23±0.014 AU and also caused physical deformities in E. coli and B. cereus such as pitting, adhesion, breakage, and shrivelling, indicating destruction of their membrane and nucleic acid leakage.

From the conducted research, it was observed that BA has good antimicrobial activity against both Gram-negative and Gram-positive foodborne pathogens, indicating its potential use in the food industry as an effective antimicrobial against foodborne pathogens, with the potential for enhancing food safety and quality.