Antibacterial Properties of a Boswellia serrata Nanoemulsion Gel in Comparison to Its Hydroalcoholic Extra

Introduction: Bacterial infections are a major health concern worldwide. Although antibiotics are widely used as cost-effective treatments, the rise of multidrug-resistant bacteria has limited their efficacy, increasing the search for alternative antimicrobial agents, particularly plant-derived products. Boswellia serrata, rich in bioactive compounds, has recently been investigated for antibacterial potential. This study evaluated the antibacterial activity of a B. serrata nanoemulsion-based gel compared with its hydroalcoholic extract. Methods: Bacterial strains, including Escherichia coli (ATCC ۲۵۹۲۲), Pseudomonas aeruginosa (ATCC ۲۷۸۵۳), Klebsiella pneumoniae (ATCC ۹۹۹۷), Staphylococcus aureus (ATCC ۲۵۹۲۳), and Enterococcus faecalis (ATCC ۲۹۲۱۲), were tested. Nanoemulsions were characterized using dynamic light scattering and transmission electron microscopy. Moreover, the functional groups of the extract and gel were examined by Fourier-transform infrared spectroscopy. Antibacterial activity was assessed by the microbroth dilution method to determine the minimum inhibitory concentration (MIC). Results: The hydroalcoholic extract demonstrated MICs of ۲۰ mg/mL for S. aureus and P. aeruginosa,>۲۰ mg/mL for E. coli and K. pneumoniae, and ۲.۵ mg/mL for E. faecalis. Furthermore, the nanoemulsion showed MICs of<۵۰ mg/mL for E. coli, K. pneumoniae, and P. aeruginosa, as well as ۲۵ mg/mL and ۶.۵ mg/mL for S. aureus and E. faecalis. The gel formulation also displayed MICs of<۵۰ mg/mL for E. coli, K. pneumoniae, and P. aeruginosa, as well as ۱۲.۵ mg/mL and ۶.۲۵ mg/mL for S. aureus and E. faecalis. Conclusion: Both formulations displayed antibacterial activity, particularly against Gram-positive bacteria. The hydroalcoholic extract was more potent, suggesting promise as a natural antimicrobial agent.