Comparative Anticancer Potential of Biologically and Chemically Synthesized Gold Nanoparticles

The present study was aimed to evaluate the anticancer behaviour of the biogenic and chemically synthesized gold nanoparticles (GNPs) towards cancerous (HeLa, MCF-7, A549 and H1299) and normal (HEK293) cell lines. We observed that biologically synthesized particles were spherical with average size ranging from 2 to 10 nm, whereas the chemically synthesized particles were polydispersed with average size ranging from 5 to 20 nm. SEM analysis suggested the crystalline behaviour of the synthesized particles. Imaging results revealed that the particles were able to penetrate the cells with localization in cytosol or in the nucleus. Cell viability assay suggested the biologically synthesized particles significantly inhibited the growth of cancerous cells in a dose dependent manner with an IC50 value of around 200 µg/mL and were found to be non-toxic towards normal cells (HEK293). While the citrate capped particles were observed to be able to kill only around 20–25% of cells even at a high concentration of 400 µg/mL. Colony suppression studies, intracellular ROS estimation, cell cycle arrest and deregulation of mitochondrial membrane potential showed the high anticancer efficiency of biologically synthesized particles in comparison to chemically synthesized particles. Based on these observations we confirm Ocimum tenuiflorum extract stabilized GNPs have potentially promising antitumor substrates.