Novel antibacterial efficacy of ZnO nanocrystals/Ag nanoparticles loaded with extract of Ximenia americana L. stem bark for wound healing

Abstract

Wound healing is a dynamic process that depends on external factors, such as the possibility of infection in the lesion area by different bacteria. In addition to synthetic drugs, other alternative substances have been proposed for healing purposes, such as medicinal plants, herbs, and bactericidal nanomaterials. In this research, we evaluated the combination of stem bark Ximenia americana L. ethanolic extract with zinc oxide (ZnO) nanocrystals/silver nanoparticles (AgNPs) for in vivo wound healing activity in Mus musculus mice. Moreover, we explain the phytochemical profile of X. americana (stem bark), and the morphological features of ZnO nanocrystals/AgNPs. The identification of bioactive compounds present in the ethanolic extract of X. americana using high-performance liquid chromatography (HPLC) showed catechin, (-)-epicatechin, rutin, and myricetin flavonoids. HPLC spectra prove that catechin is the majority component with a 3.88 g/kg concentration. X-ray diffraction patterns indicated that ZnO nanocrystals/AgNPs are pristine with a hexagonal structure. Field emission scanning electron microscope image demonstrated the presence of spherical ZnO nanocrystals with an average size of ∼ 55 nm. The mice treated with the combination of ZnO/AgNPs/Extract showed higher values of skin resistance (5 Kgf) in the treatment periods as compared to the other groups, which reduces the number of neutrophils and macrophages inducing of significative forms in the negative control group. A better process of fibroplasia was observed in the group treated with ZnO/AgNPs/Extract, evidenced by the increase in fibroblasts and collagen fibers. The results showed that using X. americana stem bark extract in combination with ZnO/AgNPs contributed to the healing of skin lesions by reducing the inflammatory process and increasing the deposition of collagen fibers.