Evaluation of the efficacy of rutin, rutin nanocrystals, and rutin spanlastics nanoparticles as antitumor and antioxidant drug delivery systems

Abstract

Flavonoids comprise an exclusive class of biomolecules with extensive therapeutic features. Rutin is one of the flavonoids that has antioxidant, anticancer, and other pharmacological actions, but its clinical use is deterred by poor solubility, poor bioavailability, and incomplete absorption. Development of nanotechnology-based delivery platforms is a promising solution to counter these issues. We evaluated the antioxidant and anticancer properties of nanocrystals and spanlastic nanoparticles of rutin against the human breast adenocarcinoma cell line MCF-7 to establish effective delivery methods with improved therapeutic efficacy. The physicochemical characteristics of the nano-formulations were investigated through particle size and zeta potential measurement, Fourier Transform Infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), electronic bandgap energy, and dissolution behavior. Antioxidant activity was investigated through DPPH and ABTS radical scavenger assays. Anticancer potential was established through a viability assay, cell cycle analysis, dual labeling with annexin-V/propidium iodide (PI) (using fluorescence-activated flow cytometric methods), and Caspase 3 activity. Rutin spanlastic nanoparticles showed a considerably smaller particle size, homogeneous dispersion, and negative zeta potential, indicating stability. Rutin spanlastic nanoparticles exhibited greater antioxidant activity compared with free rutin and rutin nanocrystals, as manifested through stronger inhibition of the viability of MCF-7 cells, stronger induction of apoptosis (annexin-V/PI double staining and Caspase 3 activity), and significant G1/0 phase cell cycle arrest. These observations imply an increased solubilization and elastovesicular behaviour of spanlastic nanoparticles with enhanced bioactivity of rutin. In conclusion, rutin spanlastic nanoparticles are an efficient delivery vehicle compared to rutin nanocrystals or free rutin in amplifying both antioxidant and anticancer activity, hence warranting further in vivo experiments to treat breast carcinoma.