Kei-apple-mediated NiO nanoparticles and biological studies: anti-inflammatory and cytotoxicity study against HeLa and HEK 293 cell lines

Abstract

Nickel oxide (NiO) nanoparticles are gaining popularity in multiple fields owing to their useful properties. The application in biomedicine has been further enhanced by combining them with plant extracts that possess unique biological properties. In this report, NiO nanoparticles were synthesized by mediating the reaction process with the leaf extracts of Kei-apple (Dovyallis Caffra), a local fruit tree found in South Africa. Various characterization techniques such as x-ray diffraction (XRD), V–Vis spectroscopy (UV–Vis), transmission electron microscope (TEM), Scanning electron microscope (SEM), and Energy dispersive x-ray analysis (EDX) were employed to establish the different physicochemical properties of the prepared NiO material. The XRD report obtained confirmed the formation of NiO nanoparticles with an average crystallite size of 9 mm. Furthermore, the microscopic techniques showed that the material possessed a spherical-shaped structure, with diameter sizes smaller than 27.18 nm (average size of about 11 nm). The purity of the material was shown in the EDX analysis, in which the primary composition was only the elemental constituents of the NiO nanoparticles. The nanoparticles exhibited good cytotoxicity comparable to the 5-Fluorouracil in both the Human embryo kidney (HEK 293) and Human cervical cancer (HeLa) cell lines, with a half maximal inhibitory concentration (IC50) value of 0.00015 and 13.8 μg ml−1, respectively. The anti-inflammatory study, on the other hand, exhibited a weak anti-inflammatory effect in the used Bovine serum albumin denaturation assay. The finding here thus suggests that the Kei-apple mediated NiO nanoparticles can be safely used in different fields without causing any appreciable harm to the human body due to the specificity to the cancerous cell line and the observed weak viability in the used non-cancerous embryonic kidney cells.