Due to their versatile applications, ZnONPs have been formulated by several approaches, including green chemistry methods. In the current study, convenient and economically viable ZnONPs were produced using Elaeagnus angustifolia (EA) leaf extracts. The phytochemicals from E. angustifolia L. are believed to serve as a non-toxic source of reducing and stabilizing agents. The physical and chemical properties of ZnONPs were investigated employing varying analytical techniques (UV, XRD, FT-IR, EDX, SEM, TEM, DLS and Raman). Strong UV–Vis absorption at 399 nm was observed for green ZnONPs. TEM, SEM and XRD analyses determined the nanoscale size, morphology and crystalline structure of ZnONPs, respectively. The ZnONPs were substantiated by evaluation using HepG2 (IC₅₀: 21.7 µg mL⁻¹) and HUH7 (IC₅₀: 29.8 µg mL⁻¹) cancer cell lines and displayed potential anticancer activities. The MTT cytotoxicity assay was conducted using Leishmania tropica “KWH23” (promastigotes: IC₅₀, 24.9 µg mL⁻¹; and amastigotes: IC₅₀, 32.83 µg mL⁻¹). ZnONPs exhibited excellent antimicrobial potencies against five different bacterial and fungal species via the disc-diffusion method, and their MIC values were calculated. ZnONPs were found to be biocompatible using human erythrocytes and macrophages. Free radical scavenging tests revealed excellent antioxidant activities. Enzyme inhibition assays were performed and revealed excellent potential. These findings suggested that EA@ZnONPs have potential applications and could be used as a promising candidate for clinical development.

Chemically nickel oxide nanoparticles (NiONPs) involve the synthesis of toxic products, which restrict their biological applications. Hence, we developed a simple, eco-friendly, and cost-efficient green chemistry method for the fabrication of NiONPs using fresh leaf broth of Rhamnus triquetra (RT). The RT leaves broth was used as a strong reducing, capping, and stabilizing agent in the formation of RT-NiONPs. The color change in solution from brown to greenish black suggests the fabrication of RT-NiONPs which was further confirmed by absorption band at 333 nm. The synthesis and different physicochemical properties of RT-NiONPs were investigated using different analytical techniques such as UV-Vis (ultraviolet−visible spectroscopy), XRD (X-ray powder diffraction), FT-IR (Fourier-transform infrared spectroscopy), SEM (scanning electron microscopy), TEM (transmission electron microscopy), EDS (energy-dispersive X-ray spectroscopy), DLS (dynamic light scattering) and Raman. Further, RT-NiONPs were subjected to different in vitro biological activities and revealed distinctive biosafe and biocompatibility potentials using erythrocytes and macrophages. RT-NiONPs exhibited potential anticancer activity against liver cancer cell lines HUH7 (IC₅₀: 11.3 µg/mL) and HepG2 (IC₅₀: 20.73 µg/mL). Cytotoxicity potential was confirmed using Leishmanial parasites promastigotes (IC₅₀: 27.32 µg/mL) and amastigotes (IC₅₀: 37.4 µg/mL). RT-NiONPs are capable of rendering significant antimicrobial efficacy using various bacterial and fungal strains. NiONPs determined potent radical scavenging and moderate enzyme inhibition potencies. Overall, this study suggested that RT-NiONPs can be an attractive and eco-friendly candidate. In conclusion, current study showed potential in vitro biological activities and further necessitate different in vivo studies in various animal models to develop leads for new drugs to treat several chronic diseases.