The <i>Aquilegia pubiflora</i> (Himalayan columbine) mediated synthesis of nanoceria for diverse biomedical applications

Abstract

Herein, we report an eco-friendly, facile, one-pot, green synthesis of nanoceria for multiple biomedical applications. In the study, cerium oxide nanoparticles (CeO₂-NPs) were synthesized using a simple aqueous extract of <i>Aquilegia pubiflora</i> as an effective reducing and capping agent. The biosynthesized nanoparticles were characterized <i>via</i> UV-vis spectroscopy, X-ray powder diffraction (XRD), high-performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. The NPs were highly stable, exhibited high purity, and had a spherical morphology and mean size of 28 nm. FTIR and HPLC studies confirmed the successful capping of bioactive compounds on the nanoparticles. The well-characterized NPs were evaluated for a number of biomedical applications, and their antimicrobial (antifungal, antibacterial, and antileishmanial), protein kinase inhibition, anticancer, antioxidant, anti-diabetic and biocompatibility properties were studied. Our results showed that the <i>Aquilegia pubiflora</i> mediated CeO₂-NPs were highly active against fungal strains, compared to the tested bacterial strains, with <i>Aspergillus niger</i> resulting in the largest zone of inhibition (15.1 ± 0.27 mm). The particles also exhibited dose dependent leishmanicidal activity with significant LC₅₀ values toward both the amastigote (114 μg mL^-1) and promastigote (97 μg mL^-1) forms of the parasite <i>Leishmania tropica</i> (KWH23). The NPs were found to be moderately active against the HepG2 cell line, showing 26.78% ± 1.16% inhibition at 200 μg mL^-1. Last but not least, their highly biocompatible nature was observed with respect to freshly isolated human red blood cells (hRBCs), making the greenly synthesized CeO₂-NPs a novel candidates for multidimensional medical applications.