Silver nanoparticles instigate physiological, genotoxicity, and ultrastructural anomalies in midgut tissues of beetles

Abstract

Silver nanoparticles (AgNPs) have long been materials of great interest in numerous fields; however, there is escalating alarm over their toxicity to public health since exposure to these particles is inevitable. This study sheds light on the deleterious impacts of AgNPs on the midgut tissues of beetles (Blaps polychresta) collected from Egypt as a biological model. The investigations were conducted on the beetles administered with a sublethal dose of AgNPs (0.03 mg/g body weight) after 30 days. Oxidative stress parameters and antioxidant enzyme activities were assessed, which exposed critical disruption in the antioxidant defense system of treated beetles. Remarkably, metallothionein (MT) gene expression was significantly increased, while reduced glutathione (GSH) level was notably decreased in midgut tissues subjected to AgNPs. These findings manifestly imply the presence of overproduction in terms of reactive oxygen species (ROS) inside the cells. Additionally, DNA impairment and apoptosis of midgut cells were appraised employing comet and flow cytometry analyses, respectively. The comet results revealed a significant increase in comet cells for the AgNPs treated beetles compared with the control group. Furthermore, the apoptosis results demonstrated a substantial diminution in viable cells with significant growth in apoptotic cells in midgut cells exposed to AgNPs, manifesting their striking correlation with comet and biochemical findings. Noticeably, the histopathological and ultrastructural inspections revealed substantial aberrations in the midgut tissues in the AgNPs treated group, substantiating the previous results. As far as we know, no research has been found that surveyed how the AgNPs at low doses affect the midgut tissues of beetles. Overall, these findings evince the aberrant influences of AgNPs on living organisms.