Genotoxic Effects on Daphnia magna Fed with Aquatic Green Algae Exposed to Silver Nanoclusters

Abstract

Ag nanoclusters (AgNCs) have gained widespread applications in recent years due to their excellent antimicrobial efficacy and distinctive molecule-like characteristics. However, concerns about their potential effects on environmental and human health have been raised. Despite the fact that abundant research has been carried out to examine the possible ecotoxicology of AgNCs in a variety of living organisms, these studies have mostly concentrated on the toxicology of individual organisms and only a few have attempted to look into the impact of AgNCs across the aquatic food chain. This work evaluated the transcriptome level genotoxicity of AgNCs and their degraded Ag ions in two model species food chains: the aquatic green algae Scenedesmus obliquus and the invertebrate Daphnia magna. Daphnia magna’s digestive system and glycerophospholipid metabolism were hindered after feeding on Ag-containing algae as a result of down-regulation of the crucial gene PLA2G(SPLA2) that codes for secretory phospholipase A2. Our research also showed that the genotoxicity of AgNCs to Daphnia magna was mediated by a synergic interaction between the particulate form of AgNCs and their degraded Ag ions. The current work offers a fresh viewpoint on the mechanisms underlying AgNCs’ harmful effects and the possible ecological concern that metal-based nanoparticles provide to aquatic life.