Green synthesis of MgO nanoparticles using Pentatropis capensis: potential to antibacterial, antioxidant, cytotoxic effects and toxicity assessments of Danio rerio

Abstract

Pentatropis capensis is a medicinal plant with diverse therapeutic applications; however, its potential as a bioresource for the eco-friendly synthesis of MgO NPs remains largely unexplored. The current study focused in the green synthesis MgO NPs using P. capensis leaf extract and evaluate their physicochemical characteristics, biological activities, and developmental toxicity. Characterization of the biosynthesized MgO nanoparticles were analyzed by FE-SEM, UV–Vis, XRD, FTIR and EDX analyses. UV–Vis spectroscopy showed a characteristic absorption peak at 274 nm, while FE-SEM revealed predominantly rod-shaped and the mean particle size of the obtained nanoparticles was determined to be 27.37 nm. EDX confirmed the elemental composition of MgO NPs. The biosynthesized MgO NPs exhibited significant antibacterial activity against Escherichia coli, producing a maximum inhibition zone of 19 mm at 100 µg mL⁻¹. They also demonstrated potent antioxidant activity showing IC₅₀ values of 59.74 µg mL⁻¹ for ABTS and 54.31 µg mL⁻¹ for DPPH, along with strong anti-inflammatory activity as evidenced by showing an IC₅₀ of 21.17 µg/mL for HRBC membrane stabilization and 23.13 µg/mL for protein denaturation assay. Furthermore, the nanoparticles exhibited promising cytotoxic activity against HT-29 human colon cancer cells, with an IC₅₀ value of 53.93 µg/mL in the MTT assay. Zebrafish embryo toxicity assessment revealed minimal developmental abnormalities at concentrations below 80 µg/mL, indicating low developmental toxicity and negligible effects on growth and neurobehavior. These findings demonstrate that green-synthesized MgO NPs from P. capensis possess promising antibacterial, antioxidant, anti-inflammatory, and anticancer properties with acceptable biocompatibility, supporting their future use in biomedical and environmental applications.

Graphical Abstract