Potential bactericidal activity of S. nux-vomica–ZnO nanocomposite against multidrug-resistant bacterial pathogens and wound-healing properties

Abstract

Multidrug resistance in bacterial strains has become the greatest challenge for healthcare professionals for treating non-healing ulcers such as diabetic foot infections (DFI). Plant-mediated synthesis of S. nux-vomica–ZnO nanocomposite appears as a potential new alternative therapeutic agent that might be capable of tackling antibiotic-resistant bacterial pathogens and for treating a non-healing ulcer. The aim of the study was to investigate the antibacterial potential of S. nux-vomica–ZnO nanocomposite biosynthesised from Strychnos nux-vomica against multidrug-resistant organisms (MDROs) from DFU, wound-healing properties, and cytotoxic effects. The antibacterial potential was assessed by minimum inhibitory concentration (MIC)/ minimum bactericidal concentration (MBC) assays, time-kill kinetics, protein-leakage, and flow cytometric analysis. The wound-healing properties were assessed by scratch assay on mouse L929 fibroblastic cell line to quantify cell migration towards the injured area. Cytotoxicity was assessed using 3-[4,5-dimethyl-2-thiazol-yl]-2,5-diphenyl- 2H-tetrazolium bromide (MTT) cellular viability assay on the L929 cell line and human embryonic kidney epithelial (HEK-293) cell line. Strychnos nux-vomica–ZnO nanocomposite at a size range of 10–12 nm exhibited significant bactericidal potency at a concentration of 100–200 μg/ml against MDR–Methicillin-resistant Staphylococcus aureus, MDR–Escherichia coli, MDR–Pseudomonas aeruginosa, MDR–Acinetobacter baumannii, and also against standard bacterial strains S. aureus ATCC 29213, E. coli ATCC 25922, P. aeruginosa ATCC 27853, E. faecalis ATCC 29212. S. nux-vomica–ZnO nanocomposite also exhibited wound-healing and reduced cytotoxic properties at the antimicrobially active concentrations. Our findings thus suggested remarkable bactericidal properties of S. nux-vomica–ZnO nanocomposite and can be further exploited towards for the development of an antibacterial agent against the threatening superbugs