Conclusion
Therefore, it can be concluded that higher concentrations of gAgNPs may induce significant cytotoxicity and cause DNA damage and apoptosis.
Discussion
It was clear from the observations of this experiment that higher concentrations of gAgNPs reduce cell viability. The production of reactive oxygen species (ROS) was evaluated by using DCFDA. The gAgNPs induced more ROS in the HuH-7 cells than in the CHANG cells. The fragmentation of DNA was evaluated by alkaline single-cell gel electrophoresis and the maximum DNA strand breakage was found at a higher concentration exposure of gAgNPs for 24 h. It is important to notice that the HuH-7 cells showed an increased sensitivity to gAgNPs than the CHANG cells. The apoptotic and necrotic effects of gAgNPs on both the cells were evaluated using annexin-V-FITC and propidium iodide staining. An increased count of apoptotic and necrotic cells was found following a higher concentration exposure of gAgNPs. The apoptotic protein expression in these cells due to gAgNPs exposure was determined using immunoblotting techniques and the level of Bcl2 was decreased. However, the expression of BAX and protein was increased in both cells. Conclusion: Therefore, it can be concluded that higher concentrations of gAgNPs may induce significant cytotoxicity and cause DNA damage and apoptosis.
Methods
The synthesized green silver nanoparticles (gAgNPs) were characterized by dynamic light scattering (DLS) and high-resolution transmission electron microscope (HR-TEM). The gAgNPs had a round shape and the mean size was 20-50 nm. The cytotoxic effects of gAgNPs were determined in human hepatic normal (CHANG) and cancer (HUH-7) cells by using tetrazolium salt (MTT) and lactate dehydrogenase (LDH) assays for 24 h.