Facile green synthesis approach for the production of chromium oxide nanoparticles and their different in vitro biological activities.

Green synthesis of nanoparticles using plants has become a promising substitute for the conventional chemical synthesis methods. In the present study, our aim was to synthesize chromium oxide nanoparticles (Cr₂ O₃ NPs) through a facile, low-cost, eco-friendly route using leaf extract of Rhamnus virgata (RV). The formation of Cr₂ O₃ NPs was confirmed and characterized by spectroscopic profile of UV-Vis, EDX, FTIR, and XRD analyses. The UV-visible spectroscopy has confirmed the formation of Cr₂ O₃ NPs by the change of color owing to surface plasmon resonance. The bioactive functional groups present in the leaf extract of RV involved in reduction and stabilization of Cr₂ O₃ NPs were determined by FTIR analysis. Based on XRD analysis, crystalline nature of Cr₂ O₃ NPs was determined. The morphological shape and elemental composition of Cr₂ O₃ NPs were investigated using SEM and EDX analyses, respectively. With growing applications of Cr₂ O₃ NPs in biological perspectives, Cr₂ O₃ NPs were evaluated for diverse biopotentials. Cr₂ O₃ NPs were further investigated for its cytotoxicity potentials against HepG2 and HUH-7 cancer cell lines (IC₅₀ : 39.66 and 45.87 μg/ml), respectively. Cytotoxicity potential of Cr₂ O₃ NPs was confirmed against promastigotes (IC₅₀ : 33.24 μg/ml) and amastigotes (IC₅₀ : 44.31 μg/ml) using Leishmania tropica (KMH₂₃ ). The Cr₂ O₃ NPs were further evaluated for antioxidants, biostatic, alpha-amylase, and protein kinase inhibition properties. Biocompatibility assay was investigated against human macrophages which confirmed the nontoxic nature of Cr₂ O₃ NPs. Overall, the synthesized Cr₂ O₃ NPs are biocompatible and nontoxic and proved to possess significant biopotentials. In future, different in vivo studies are needed to fully investigate the cytotoxicity and mechanism of action associated with these Cr₂ O₃ NPs.