Alteration of cholinesterase activity as possible mechanism of silver nanoparticle toxicity

Abstract

Due to their broad-spectrum antimicrobial activity, silver nanoparticles (AgNPs) have been used in a large number of commercial and medical products. Such proliferated AgNP production poses toxicological and environmental issues which need to be addressed. The present study aimed to investigate the effects of AgNPs on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), important enzymes in areas of neurobiology, toxicology and pharmacology. Three different AgNPs, prepared by the chemical reduction using trisodium citrate, hydroxylamine hydrochloride (Cl-AgNPs), and borohydride following stabilization with poly(vinyl alcohol), were purified and characterised with respect to their sizes, shapes and optical properties. Their inhibition potential on AChE and BChE was evaluated in vitro using an enzyme assay with o-nitrophenyl acetate or o-nitrophenyl butyrate as substrates, respectively. All three studied AgNPs were reversible inhibitors of ChEs. Among tested nanoparticles, Cl-AgNP was found to be the most potent inhibitor of both AChE and BChE. Although the detailed mechanism by which the AgNPs inhibit esterase activities remains unknown, structural perturbation of the enzyme may be the common mode of ChE inhibition by AgNPs.

Protein Corona Modulates Distribution and Toxicological Effects of Silver Nanoparticles In Vivo

“…At cellular level, generation of reactive oxygen species (ROS) and oxidative stress, alteration of mitochondrial function, inflammation, and induction of DNA damage have been reported as the most plausible mechanisms of AgNP toxicity, although detailed and consistent data are still missing. We have also demonstrated a similar mode of toxic actions for AgNPs in a wide range of mammalian cells including liver, kidney, and brain cells …”

“…We have also demonstrated a similar mode of toxic actions for AgNPs in a wide range of mammalian cells including liver, kidney, and brain cells. [27][28][29][30][31] Like for all chemicals and bulk materials, biological and/or toxicological effects of NPs in every single living system will be dependent on both physicochemical properties and the characteristics of the surrounding biological environment. Thus, different types of interactions should be considered when AgNPs reach specific tissues, cells, or circulatory system.…”

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

“…Adsorption and non‐specific inactivation are two common types of interactions between proteins and NPs. Our previous studies (Šinko et al, ) and others (Auffan et al, ) have already shown that Ag + ions interact with proteins, i.e. albumin and cholinesterases.…”

The Increase in Temperature Overwhelms Silver Nanoparticle Effects on the Aquatic Invertebrate Limnephilus sp.

“…Metal‐based NPs and ionic form of metals have been reported to affect the activities of AChE in aquatic organisms (Pradhan et al 2016). Moreover, AgNPs have been reported to inhibit AChE in a dose‐dependent manner (Šinko et al 2014).…”