Plant-mediated synthesis of nickel oxide nanoparticles (NiO) via Geranium wallichianum: characterization and different biological applications

In the current study, we reported green synthesis of NiO nanoparticles (NiONPs) using Geranium wallichianum as both reducing and capping agent. The formation, morphology, crystalline structure, elemental composition, surface charge and stability were studied using different characterization techniques; x-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), FTIR, Energy-dispersive spectroscopy (EDS), Raman spectroscopy, dynamic light scattering (DLS) and UV spectroscopy which confirmed the synthesis of pure NiONPs (similar to 21 nm). Detailed in vitro biological activities have revealed significant therapeutic potentials for NiONPs. Strong antifungal and antibacterial activities are reported for NiONPs. NiONPs have shown potential cytotoxicity against HepG2 cancer cells (IC50 : 37.84 mu g ml(-1)). Moderate antileishmanial activities against Leishmania tropica (KMH23) promastigotes (IC50 : 22.12 mu g ml(-1)) and amastigotes (IC50 : 26.58 mu g ml(-1)) cultures are revealed. For toxicological assessment, NiONPs were found compatible towards human RBCs and macrophages (IC50 : >200 mu g ml(-1)), deeming particles safe for various biomedical applications. In addition, antioxidant activities, protein kinase and alpha amylase inhibition assays were also performed. In conclusion, NiONPs have shown potential biological applications and should be subjected to further in vivo studies on toxicity in animal models to develop its nano-pharmacological relevance in biomedical applications.