Investigation of the Effects of Silicon Dioxide Nanoparticles and Environmental Contaminants on Immunocytotoxic and Antioxidant Defence Systems in Model Organism Galleria mellonella L

Silicon dioxide (SiO₂) nanoparticles are chemically stable, biocompatible, abundant and inexpensive. Moreover, they have highly surface-reactive. These properties make them suitable for environmental applications but also raise questions about their reactivity with environmental contaminants. In the study, enzyme activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), cytochrome P450 (Cyt P450), glutathione-s-transferase (GST), acetylcholinesterase (AChE) and total, differential haemocyte counts and apoptotic index were investigated in haemolymph, midgut and fat body of Galleria mellonella exposed to LD ₅₀ value of SiO ₂ NP, environmental concentration of abamectin, cadmium sulphate (CdSO ₄ ) and copper sulphate (CuSO ₄ ) singly and in mixture. The total hemocyte count decreased in the SiO ₂ and CdSO ₄ singly applied groups however an increased were observed in the SiO ₂ NPs + CdSO ₄ mixture and a decreased were observed in the SiO ₂ NPs + abamectin group compared with the control. As for differential hemocyte counts, prohemocytes, plasmatocytes, spherulocytes, granulocytes, and oenocytoids was altered following treatment with SiO ₂ NPs, CdSO ₄ , and abamectin singly and in mixture. As a result of this study, it was determined that SiO ₂ NPs, CdSO ₄ and Abamectin lead to toxic effects in G. mellonella larvae as a result of single and mixture applications and it was also observed that SiO ₂ NPs may increase the toxic effects of environmental pollutants on antioxidant defence and immune system depending on tissue differences as a result of mixture applications.