Green synthesis of copper oxide nanoparticles using Artemisia annua aqueous extract and its characterization, antioxidant, and burn wound healing activities

The current study reports a simple and eco-friendly method for synthesis of copper oxide nanoparticles (CuO NPs) using an aqueous extract of Artemisia annua. The green synthesized CuO NPs were characterized using UV–Vis, FT-IR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy, and energy dispersive X-ray analysis (EDX). The UV–Vis spectroscopy showed maximum absorption at 250 nm, and the average diameter of the biosynthesized NPs was found to be 35 nm. FTIR showed the presence of functional groups, especially C=O and O–H in bioactive constituents present that acted as reducing and capping agents during the biosynthesis of CuO NPs. The antioxidant activity of the biosynthesized CuO NPs was evaluated by DPPH assay, which showed that at 100 µg/ml, the highest antioxidant activity of 67% with an IC50 value of 73.48 µg/ml. In the in vivo experiment, after inducing 2nd degree burn wounds, the rats were randomly divided into five groups, including the untreated control, treatment groups with eucerin ointment, 0.2% CuO NPs ointment, 0.2% biosynthesized CuO NPs ointment, and 5% Artemisia annua extract, respectively, twice a day for 21 days. Application of biosynthesized CuO NPs ointment significantly increased the levels of transforming growth factor-beta1 (TGF- β 1) and hydroxyproline compared to the control. Additionally, histopathology studies showed significant progress in re-epithelization, collagen fiber deposition, and angiogenesis in the biosynthesized CuO NPs. The green synthesized CuO NPs had enhanced antioxidant, and wound healing properties and, therefore, could be considered a promising candidate in the biomedical field.