Comparison ofin vitrotoxicity of silver ions and silver nanoparticles on human hepatoma cells

Abstract

Scientific information on the potential harmful effects of silver nanoparticles (AgNPs) on human health severely lags behind their exponentially growing applications in consumer products. In assessing the toxic risk of AgNP usage, liver, as a detoxifying organ, is particularly important. The aim of this study was to explore the toxicity mechanisms of nano and ionic forms of silver on human hepatoblastoma (HepG2) cells. The results showed that silver ions and citrate-coated AgNPs reduced cell viability in a dose-dependent manner. The IC50 values of silver ions and citrate-coated AgNPs were 0.5 and 50 mg L(-1) , respectively. The LDH leakage and inhibition of albumin synthesis, along with decreased ALT activity, indicated that treatment with either AgNP or Ag ions resulted in membrane damage and reduced the cell function of human liver cells. Evaluation of oxidative stress markers demonstrating depletion of GSH, increased ROS production, and increased SOD activity, indicated that oxidative stress might contribute to the toxicity effects of nano and ionic forms of silver. The observed toxic effect of AgNP on HepG2 cells was substantially weaker than that caused by ionic silver, while the uptake of nano and ionic forms of silver by HepG2 cells was nearly the same. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 679-692, 2016.

Cytotoxicity of β-D-glucose/sucrose-coated silver nanoparticles depends on cell type, nanoparticles concentration and time of incubation

“…Several reports show that AgNPs enter HepG2 cells localizing in the cytoplasm [34][35][36][37][38][39][40], nuclei [41] and mitochondria [35] at large amount irrespective of agglomeration state [35]. Current studies confirm the toxicity of AgNPs to HepG2 and the impact are very contradictory depending on different NPs sizes, coating types and amounts considered: in general, the smaller AgNPs enter into HepG2 cells more efficiently and are more toxic than the larger ones.…”

Toxic effects of silver nanoparticles in mammals – does a risk of neurotoxicity exist?

“…Both decreased [6,130] and increased [141] SOD activity has been observed. It was also found that exposure to AgNPs leads to a decrease in the activity levels of glutathione peroxidases in a human liver cell line [130].…”

“…This mechanism of AgNPs toxicity may be confirmed by the fact that weak antioxidants with -SH groups such as 2,3-dithiopropanol [26], N-acetylcysteine (NAC) [62], methionine and cysteine are more effective against AgNP-induced cytotoxicity than the most potent antioxidants without thiol groups such as Trolox (water soluble vitamin E analog) or Tempol [126]. Overproduction of ROS during exposure to AgNPs has been proven directly in several in vitro investigations [15,26,78,141] and also in vivo [30,103]. Among the oxidative stress-related changes caused by AgNPs, depletion of reduced glutathione (GSH) has been observed in human skin carcinoma cells [6], rat liver cells [60], mouse macrophage cells [100], human liver cells [106,141] and mouse embryonic fibroblasts [74].…”

“…Overproduction of ROS during exposure to AgNPs has been proven directly in several in vitro investigations [15,26,78,141] and also in vivo [30,103]. Among the oxidative stress-related changes caused by AgNPs, depletion of reduced glutathione (GSH) has been observed in human skin carcinoma cells [6], rat liver cells [60], mouse macrophage cells [100], human liver cells [106,141] and mouse embryonic fibroblasts [74]. Results of studies on aquatic organisms strongly support these in vitro observations [3,38,86], whereas limited in vivo studies demonstrate a lack of changes in GSH levels in liver of exposed rodents [32,39].…”

Silver nanoparticles induced neurotoxicity through oxidative stress in rat cerebral astrocytes is distinct from the effects of silver ions

“…_ 6 ) T D $ F I G ] coated AgNPs and silver ions were 84 and 25 mg/L in zebrafish (Bilberg et al, 2012). The 24-h IC 50 values of silver ions and citratecoated AgNPs were 0.5 and 50 mg/L for HepG2 cells (Vrček et al, 2014). In this study, the 24-h IC 50 values based on rat astrocyte cultures also showed that silver ions caused relatively higher cytotoxicity than AgNPs and the difference in the toxicities between these two silver species was approximate 10 folds.…”