In vitro evaluation of antibacterial activity of berberine nano gel on standard bacterial strains associated with burn wound infections

Abstract

Objective: To evaluate the In vitro antibacterial activity of berberine nanogel against reference bacterial strains and compare it with a reference control.
Subjects and methods: In vitro experimental design. Antibacterial activity was quantified using the agar disk diffusion method (zone of inhibition, mm). Time-kill assays were conducted using twofold serial dilutions (from 1/2 to 1/128) with with bacterial growth assessed at 2, 6, and 24 hours for Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.
Results: The berberine nanogel produced zones of inhibition against both Gram-positive and some Gram-negative bacteria. Specifically: E. coli 17.11 ± 1.44 mm vs. the reference control 23.49 ± 2.16 mm (p < 0.001); P. aeruginosa 14.14 ± 1.61 mm vs. 14.25 ± 1.88 mm (p > 0.05); Acinetobacter sp. 19.79 ± 1.37 mm vs. 10.59 ± 1.19 mm (p < 0.001); Enterobacter sp. 15.26 ± 1.58 mm vs. 24.26 ± 0.97 mm (p < 0.001). For Gram-positive bacteria, S. aureus achieved 16.47 ± 1.54 mm vs. 11.20 ± 1.37 mm (p < 0.001). In time - kill testing, no bacterial growth was observed after 24 hours at dilutions ≥1/16 for E. coli and P. aeruginosa, and at ≥ 1/32 for S. aureus. At higher concentrations (≥1/4), early inhibition/bactericidal activity was evident as early as 2 hours.
Conclusion: Berberine nanogel demonstrated significant In vitro antibacterial activity, with pronounced effects against S. aureus and Acinetobacter sp., and efficacy comparable to the reference control against P. aeruginosa.