Differential impact of biogenic and chemically synthesized zinc oxide nanoparticles on anti-aging, anti-oxidant and anti-cancerous activities: a mechanism based study

Abstract

Zinc oxide nanoparticles (ZnONPs), characterized by their nanoscale dimensions and unique properties, have emerged as promising materials in various applications. From electronics to biomedicine, their versatility and biocompatibility makes them valuable assets to address multifaceted challenges. This study aimed to comparatively analyze chemically synthesized ZnONPs (CS-ZnONPs) and Illicium verum-mediated ZnONPs (IV-ZnONPs) in terms of characteristics and biological activities. Characterization of both types of synthesized ZnONPs were done by using various techniques namely XRD, UV-vis spectroscopy, FTIR, TEM, and EDX. TEM and XRD results revealed the variability in size and shape of IV-ZnONPs (∼13.75 nm; triangular) and CS-ZnONPs (∼38.9 nm; flower-shaped). FTIR spectra showed the presence of different phytochemicals present in I. verum extract involved in the capping of IV-ZnONPs. Both types of ZnONPs were found to be biocompatible in nature. Furthermore, variations in their biological properties were observed using different in vitro assays, such as FRAP (242.3 ± 18.9 and 101.5 ± 9.5 μM TEAC), CUPRAC (249.8 ± 8.9 and 149.5 ± 8.2 μM TEAC), ABTS (I36.2 ± 0.5 and 28.2 ± 0.8 μM TEAC), and ORAC cell-free assays (19.9 ± 0.6 and 11.9 ± 0.9 μM TEAC) for anti-oxidant investigations of IV-ZnONPs and CS-ZnONPs, respectively. Percentage Inhibition of Vespelysine-like AGEs and pentosidine-like AGEs for anti-aging analysis were reported. In addition to these, the anti-cancerous potential of both types of ZnONPs was also studied based on MTT assay, ROS/NOS production, mitochondria membrane potential, activity of caspase 3/7 measurements, and expression of caspase-3 gene in mammalian HepG2 cell lines. Our findings revealed that both types of ZnONPs were found to be more active through electron-transfer anti-oxidant mechanism. Likewise, the findings of anti-aging analyses revealed significant difference of inhibitory potential between CS-ZnONPs and IV-ZnONPs. As far as anti-cancerous potential is concerned, both IV-ZnONPs and CS-ZnONPs were found to have promising potential against HepG2 cells. However, CS-ZnONPs were observed to have a slight edge over IV-ZnONPs. Nonetheless, the overall results indicated that ZnONPs synthesized through the green route exhibit outstanding biological potential, positioning them as promising candidates for future biomedical applications, particularly in the realm of cancer therapeutics.