Phytofabricated zinc oxide nanoparticles (ZnO-NPs) from a medicinal salt-tolerant Oxystelma esculentum (L.f.) Sm. extract and their multifunctional biological activities

Abstract

This study accounts for the green synthesis of zinc oxide nanoparticles (ZnO-NPs) using Oxalis esculentum extract, aiming to evaluate their physicochemical properties and biomedical potential. The synthesized ZnO-NPs were characterized using UV–Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). XRD confirmed the hexagonal nanocrystalline nature of the ZnO-NPs, having a particle size of 13 nm, while FTIR indicated the existence of functional groups from plant phytochemicals. SEM revealed a quasi-spherical shape with agglomeration tendency, and EDX confirmed the presence of zinc (60.4%) and oxygen (22%) elements. The ZnO-NPs exhibited notable antifungal activity, with maximum inhibition rates of 72.3% against Aspergillus niger, 72.2% against Penicillium notatum, and 69.3% against Fusarium oxysporum at 4 mg/mL. Antibacterial activity against Escherichia coli peaked at a 13.9 mm inhibition zone at 8 mg/mL. The highest antileishmanial activity was 57.33% at 160 µg/mL, while hemolytic activity remained low at 1.41 ± 0.22% at 200 µg/mL, indicating biocompatibility. Additionally, the ZnO-NPs showed 79% anti-inflammatory activity at 800 µg/mL, 63.11 ± 0.22% alpha-amylase inhibition at 400 µg/mL, 17.66 ± 0.55% α-glucosidase inhibition at 400 µg/mL, and antioxidant activities, including 51.7 ± 1.2% TAC, 42.4 ± 0.02%TRP, and 55.6 ± 1.4%FRSA at 200 µg/mL of the NPs. In conclusion, the phyto-fabricated ZnO-NPs demonstrated significant antimicrobial, anti-inflammatory, antidiabetic, and antioxidant properties, highlighting their potential for future biomedical applications.