Copper and zinc impact on stress biomarkers and growth parameters in a model organism, Galleria mellonella larvae.

The objective of the present study was to investigate the impact of zinc and copper on some biomarkers in a model organism Galleria mellonella L. We investigated the effects of Cu and Zn (10, 50, and 100 mg/100 g diets) on different biomarkers such as oxidative stress parameters (SOD and CAT activities and MDA levels), energy resources (protein, lipid and glycogen levels), electrolyte contents (Ca, Na, and K levels), total hemocyte count (THC), and growth and development of G. mellonella. Additionally, the accumulation levels of the used metals were also studied. Cu caused a significant decrease in protein, lipid and glycogen levels. SOD and CAT activities significantly increased at all concentrations of Cu, while they significantly increased at only high concentrations of Zn (50 and 100 mg). Lipid peroxidation levels (MDA) significantly elevated at high concentrations of both metals. It was determined that the Cu and Zn accumulation increased depending on the increase of the concentration. Zn caused an alteration in Ca level at the concentrations of 50 and 100 mg, and K and Na levels at all concentrations. While, THC significantly reduced at all Cu concentrations, this reduction was observed only at higher Zn concentrations (50 and 100 mg). Larval and pupal development time significantly extended at the highest concentration (100 mg) of Cu, and females' lifespan significantly shortened at all concentrations of Cu. Zinc caused an extension in larval development time at the highest concentration (100 mg), and caused a shortening in females and males' lifetime at all concentrations. The observed changes in biomarkers can be used as the illustration of potential toxic effects of high levels of Cu and Zn in organisms.