Wound-Healing and Antibacterial Activity of the Quercetin–4-Formyl Phenyl Boronic Acid Complex against Bacterial Pathogens of Diabetic Foot Ulcer

[Image: see text] Complications of diabetic foot can be prevented using a naturally occurring, efficient, and newly synthesized antimicrobial agent. The purpose of the study was to improve wound healing and antibacterial effects of quercetin and its esterified complex with 4-formyl phenyl boronic acid (4FPBA–Q) compared with phenytoin. The formation of the 4FPBA–Q complex was confirmed by thin-layer chromatography (TLC), Fourier transform infrared (FTIR) spectroscopy, and mass spectrometry (MS). The prepared 4FPBA–Q complex was used against Gram-positive bacteria along with Gram-negative bacteria, and more than 2-fold decrease in minimum inhibitory concentrations (MIC) was observed compared to pure quercetin. Scanning electron microscopic images of Pseudomonas aeruginosa and Staphylococcus aureus showed their complete destruction after incubation with the 4FPBA–Q complex even after 3 h. Interestingly, wound-healing properties of the 4FPBA–Q complex in infected diabetic rats increased from 64 to 99% as compared to phenytoin, which were increased from those of noninfected diabetic rats. Furthermore, histopathological evaluations showed significantly enhanced wound healing, re-epithelialization, fibroblasts, and angiogenesis in wounds of diabetic rats after 10 days. Conclusively, reduction in the primary irritation index (PDII) and improved antibacterial and wound-healing properties render the 4FPBA–Q complex ideal for diabetic foot ulcer treatment.