Synthesis and characterization of biogenic metal nanoparticles and its cytotoxicity and anti-neoplasticity through the induction of oxidative stress, mitochondrial dysfunction and apoptosis

In the present study, we demonstrate a simple, cost-effective and eco-friendly method for biogenic synthesis of silver nanoparticles (AgNPCGs) using ethanolic extract of Calotropis gigantea latex. Attempts were made to characterize these biogenic silver nanoparticles AgNPCGs and also to test its cytotoxic, anti-neoplastic and apoptotic potential through the induction of oxidative stress, mitochondrial dysfunction. AgNPCGs were characterized by UV-vis spectroscopy, dynamic light scattering (DLS) and surface zeta potential measurement, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM) and selected area electron diffraction, scanning electron microscopy (SEM), energy-dispersive X-ray fluorescence spectrometry (EDX). UV visible spectroscopy showed an intense surface plasmon resonance band at 431nm which clearly reflected the formation of silver nanoparticles. FTIR study revealed that latex extract acted as reducing and stabilizing agent for the synthesis of AgNPCGs. Energy dispersive X-ray spectroscopy confirmed the presence of silver as a major component of synthesized AgNPCGs. SEM and TEM studies showed that the synthesized AgNPCGs were nearly spherical in shape with an average size of 2.338nm. The selected area electron diffraction pattern and XRD studies confirmed the crystalline nature of AgNPCGs. AgNPCGs exhibited in-vitro cytotoxic activity against Ehrlich's ascites carcinoma (EAC), Jurkat and MCF-7 cells at respective IC₅₀ doses without producing cytotoxicity to mice and human lymphocytes. Significant chromatin condensation, DNA fragmentation, cell cycle arrest at G₂/M phase, up-regulation of Bax and caspase-3 and down-regulation of Bcl-2 were observed in AgNPCGs treated EAC cells. The results suggest that biogenic silver nanoparticles AgNPCGs could be a potential chemotherapeutic formulation for cancer therapy.