Green synthesis of silver nanoparticles via Cynara scolymus leaf extracts: The characterization, anticancer potential with photodynamic therapy in MCF7 cells

In this study, we report on the synthesis of silver nanoparticles (AgNPs) from the leaf extracts of Cynara scolymus (Artichoke) using microwave irradiation and the evaluation of its anti-cancer potential with photodynamic therapy (PDT). Silver nanoparticles formation was characterized by scanning electron microscopy with energy dispersive x-ray spectroscopy and Fourier transform infrared (FTIR) spectroscopy. Silver nanoparticles formation was also investigated the surface charge, particle size and distribution using zetasizer analysis. The cytotoxic effect of AgNPs and/or PDT was studied by MTT assay and migration by the scratch assay. The apoptotic inducing ability of the AgNPs and/or PDT was investigated by intracellular ROS analysis, antioxidant enzyme levels (SOD, CAT, GPx and GSH), Hoechst staining and Bax/Bcl-2 analysis using western blotting. The mean particle size of produced AgNPs was found 98.47 +/- 2.04 nm with low polydispersity (0.301 +/- 0.033). Zeta potential values of AgNPs show -32.3 +/- 0.8 mV. These results clearly indicate the successful formation of AgNPs for cellular uptake. Mitochondrial damage and intracellular ROS production were observed upon treatment with AgNPs (10 mu g/mL) and PDT (0.5 mJ/cm(2)) showed significant reducing cell migration, expression of Bax and suppression of Bcl-2. Significantly, biosynthesized AgNPs showed a broad-spectrum anti-cancer activity with PDT therapy and therefore represent promoting ROS generation by modulating mitochondrial apoptosis induction in MCF7 breast cancer cells.