Oxidative stress mediated cytotoxicity of biologically synthesized silver nanoparticles in human lung epithelial adenocarcinoma cell line

Abstract

The goal of the present study was to investigate the toxicity of biologically prepared small size of silver nanoparticles in human lung epithelial adenocarcinoma cells A549. Herein, we describe a facile method for the synthesis of silver nanoparticles by treating the supernatant from a culture of Escherichia coli with silver nitrate. The formation of silver nanoparticles was characterized using various analytical techniques. The results from UV-visible (UV-vis) spectroscopy and X-ray diffraction analysis show a characteristic strong resonance centered at 420 nm and a single crystalline nature, respectively. Fourier transform infrared spectroscopy confirmed the possible bio-molecules responsible for the reduction of silver from silver nitrate into nanoparticles. The particle size analyzer and transmission electron microscopy results suggest that silver nanoparticles are spherical in shape with an average diameter of 15 nm. The results derived from in vitro studies showed a concentration-dependent decrease in cell viability when A549 cells were exposed to silver nanoparticles. This decrease in cell viability corresponded to increased leakage of lactate dehydrogenase (LDH), increased intracellular reactive oxygen species generation (ROS), and decreased mitochondrial transmembrane potential (MTP). Furthermore, uptake and intracellular localization of silver nanoparticles were observed and were accompanied by accumulation of autophagosomes and autolysosomes in A549 cells. The results indicate that silver nanoparticles play a significant role in apoptosis. Interestingly, biologically synthesized silver nanoparticles showed more potent cytotoxicity at the concentrations tested compared to that shown by chemically synthesized silver nanoparticles. Therefore, our results demonstrated that human lung epithelial A549 cells could provide a valuable model to assess the cytotoxicity of silver nanoparticles.

Combination of graphene oxide–silver nanoparticle nanocomposites and cisplatin enhances apoptosis and autophagy in human cervical cancer cells

“…13,[85][86][87][88] Recent studies suggest a potential link between ROS regulation and autophagic processes, because agents capable of inducing ROS formation play a crucial role in the induction of autophagy in embryonic kidney HEK293 cells, human fibroblast HT1080 cells, and human lung cancer cells. 84,89,90 For instance, platinum-based therapy and epigallocatechin gallate-mediated cell death may also depend on the generation of ROS either directly or indirectly. 91,92 A recent study suggested that Cis induces autophagy in HeLa cells via upregulating the formation of autophagic vesicles, promoting the conversion of LCI to LCII and increasing the expression of the autophagy-related ATG7 gene.…”

“…Recently, Han et al observed that the AgNPs induced accumulation of autophagosomes and autolysosomes in human lung carcinoma cells and combination of salinomycin and AgNPs enhanced the expression of various autophagy genes and accumulation of autophagosomes, lysosomes, and autophagolysosomes in human ovarian cancer cells. 13,84 Once autophagosomes are formed, they can merge with lysosomes to form autolysosomes, whose contents are degraded by lysosomal hydrolases. 81 Although autophagy seems to protect cells against cell death under oxidative stress, extended autophagy can induce cell death in several cases, such as precancerous cells.…”

Quercetin-mediated synthesis of graphene oxide–silver nanoparticle nanocomposites: a suitable alternative nanotherapy for neuroblastoma

“…111 Furthermore, another study on the combination of AgNPs and salinomycin also resulted in extensive ROS generation in human ovarian cancer cells, and eventually, the combination induced accumulation of APs and autolysosomes/autophagic vacuoles. 81 Consistent with our results, previous studies also reported that GO can enter the cells by interacting with the plasma membrane and probably temporarily disrupting the phospholipid bilayer or causing plasma membrane invagination in HepG2 cells and neuroblastoma cell lines, including SK-N-BE(2) and SH-SY5Y.…”

Fabrication and Characterization of Electrospun PHA/Graphene Silver Nano-Composite Scaffold for Antibacterial Application

“…The peaks at 1060 cm − 1 (C-O stretching vibrations), 1245 cm−1(C-OH stretching vibration) and 1725 cm − 1 (C=O stretching vibration) were become less intense; which suggests the reduction of graphene. The peaks in between 2924 cm − 1 to 3400 cm − 1 of silver were assigned to the stretching vibrations of primary and secondary amines, while their corresponding bending vibrations were seen at 1383 cm − 1 and 1636 cm − 1 respectively [56]. The wave number positioned around 1700 cm −1 was attributed to the stretching vibration of the C=O group (ester carbonyl) in the PHA.…”