Zaluzanin-D enriched Vernonia arborea extract mediated copper oxide nanoparticles synthesis and their anti-oxidant, anti-inflammatory and DNA methylation altering properties

Abstract

Metal oxide nanoparticles synthesized with the aid of medicinal plant extracts are showing potential as treatment options for inflammatory diseases. Two key benefits of this synthesis method is: the synthesis process is environmentally benign and the utilization of medicinal plant-derived extracts adds to the medicinal value of the synthesized nanoparticle. Earlier, sesquiterpene lactone zaluzanin-D (ZD) has been isolated from leaves of Vernonia arborea. ZD showed ability to reduce inflammation in activated monocytes. Copper oxide nanoparticles (bCuO-NPs) were synthesized using ZD-enriched leaf extract of V. arborea and characterized by UV-vis spectroscopy, FT-IR, XRD, particle size analyzer, and TEM. Synthesized bCuO-NPs did not show significant toxicity to human monocytic cell lines (THP-1) at the tested concentrations. The bCuO-NPs showed radical scavenging ability indicating anti-oxidant properties. Flow cytometry experiments proved the capability of bCuO-NPs to reduce intracellular ROS in peroxide-activated THP-1 cells. The NPs also showed a significant ability to reduce inflammatory adhesion in PMA-activated THP-1 cells. In the DNA methylation studies, bCuO-NPs behaved similarly to ZD and prevented DNA hypomethylation at the MMP-9 promoter region. These properties strongly indicate the ability of bCuO-NPs to reduce inflammation in the activated monocytes. Furthermore, in zebrafish (Danio rerio) embryos, the developmental toxicity of bCuO-NPs was assessed. The studies indicated the reduced toxicity and compatibility of the NPs with biological organisms. Based on the results, it can be concluded that the bCuO-NPs produced from ZD-enriched leaf extract have significant anti-oxidant capabilities and the ability to reduce inflammation in monocytic cell lines. Overall, reduced in vitro and in vivo toxicity, along with its antioxidant and anti-inflammatory properties, makes bCuO-NPs a potential candidate for anti-inflammatory drugs.