Effects of Cu, Zn and their mixtures on bioaccumulation and antioxidant enzyme activities in Galleria mellonella L. (Lepidoptera: Pyralidae).

The effects of Cu, Zn and their mixture on bioaccumulation and antioxidant enzyme activities of midgut and fat body of Galleria mellonella larvae were investigated. Exposure to mixtures of both metals showed a synergistic effect and the accumulation levels were increased in both tissues. When the metals were exposed separately the concentration of Zn increased in both tissues, whereas the concentration of Cu increased in midgut and decreased in fat body. Also, it was determined that, oxidative stress occurred in the midgut and fat body when G. mellonella larvae were fed singly and in a mixture with different concentrations of Cu and Zn. In addition, significant changes were observed in antioxidant and detoxification enzyme activities, which are an indicator of oxidative stress. Larvae of G. mellonella showed immune responses similar to vertebrates, and could be used as bioindicator species due to being grown easily in the laboratory and reduced research costs Understanding the detoxification mechanism in insects is an important parameter for future ecotoxicological studies on the genotoxic, cytotoxic and physiological effects that different environmental pollutants such as heavy metals can cause.

Effects of Copper Oxide Nanoparticles on Immune and Metabolic Parameters of Galleria mellonella L.

In this study, the effects of dietary CuO nanoparticles (NPs) on metabolic enzyme activity, biochemical parameters, and total (THC) and differential hemocyte counts (DHC) were determined in Galleria mellonella larvae. Using concentrations of 10, 100, 1000 mg/L and the LC10 and LC30 levels of CuO NPs, we determined that the NPs negatively impacted metabolic enzyme activity and biochemical parameters in larval hemolymph. Compared with the control, the greatest increase in THC was observed in larvae fed on diets with 100 mg L-1 of CuO NPs. Plasmatocytes and granulocytes were among the most numerous hemocytes in all treatments. These results suggest that dietary CuO NPs effects the metabolic metabolism and immune system of G. mellonella and provide indirect information regarding the toxic effects of CuO NPs in mammalian immune system given similarities between mammalian blood cells and insect hemocytes.

Ecotoxicological effects of dietary titanium dioxide nanoparticles on metabolic and biochemical parameters of model organism Galleria mellonella (Lepidoptera: Pyralidae).

Nanoparticles (NPs) are now being used in many industrial activities, such as mining, paint and glass industries. The frequent industrial use of NPs contributes to environmental pollution and may cause cellular and oxidative damage in native organisms. In this study, the toxic effects of titanium dioxide nanoparticles (TiO2 NPs) were investigated using Galleria mellonella larvae as a model insect species. Alterations in cell damage indicators, such as alanine transferase, aspartate transferase, lactate dehydrogenase, non-enzymatic antioxidants and biochemical parameters, were determined in the hemolymph of G. mellonella larvae exposed to TiO2 NPs at different concentrations (5, 50, 250 and 1250 µg/mL) in their diets. TiO2 NPs caused concentration-dependent cellular damage in the hemolymph of G. mellonella larvae and increased the levels of the non-enzymatic antioxidants uric acid and bilirubin. In addition, total protein in hemolymph significantly decreased at the highest concentration (1250 µg/mL) of TiO2 NPs. Level of the urea increased at the highest concentration (1250 µg/mL) of TiO2 NPs, whereas the amount of glucose was not affected. These findings demonstrated that TiO2 NPs caused concentration-dependent toxic effects on G. mellonella larvae.

Effects of Copper Oxide Nanoparticles on Tissue Accumulation and Antioxidant Enzymes of Galleria mellonella L.

Effects of copper oxide nanoparticles (CuO NPs) were investigated in the midgut and fat body of Galleria mellonella. Fourth instar larvae were exposed to 10 µg Cu/L of CuO until becoming last instar larvae, and catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione-s-transferase (GST) and acetylcholinesterase (AChE) and metal accumulation were evaluated. Copper accumulation was observed in midgut and fat body tissues of G. mellonella larvae exposed to CuO NPs. CuO NPs increased CAT activities in midgut and fat body, while SOD activities were decreased. CuO NPs exhibited significant increases in GST activity in fat body, while no significant differences were observed in the midgut of G. mellonella larvae. AChE activity significantly decreased in the midgut of G. mellonella whereas there is no significant effect on fat body in CuO NPs exposed larvae. In overall, these findings demonstrate that tissue accumulation and oxidative stress that is countered by antioxidant enzymes occur when G. mellonella larvae exposed to environmental concentration of CuO nanoparticles.