Investigation of Di-(2-ethylhexyl) phthalate-induced toxicity histopathologically and biochemically in Gammurus pulex

Phthalates are chemicals that are added to reduce the hardness of plastic materials, to give materials flexibility and softness. Nowadays, many cosmetic products, detergent, toys and personal care products, such as products used in daily life is used for permanent odor and coloring. In this thesis, biochemical and histopathological changes in Gammarus pulex exposed to different doses of Di- (2-Ethylhexyl) Phthalate (DEHP) are investigated and it is aimed to reveal the toxicity caused by DEHP. For this purpose, the LC50 (lethal concentration 50) value of DEHP was determined primarily using a static test. The DEHP LC value was found to be 0.079 ± 0.01 ppm, and then three sublethal doses of DEHP (1/4; 1/8 and 1/16 of the LC value) were administered to G. Pulex for 24 and 96 hours. Superoxide Dismutase (SOD), Catalase (KAT), Cytochrome p450 (CYP1A1), Glutathione S-transferase (GST) activities were measured by using ELISA kit. Kaspaz method that is a immunohistochemical analysis method was used to determine apoptosis in Gammarus pulex. CYP1A1 activities decreased in groups exposed to different DEHP doses but these changes were not statistically significant. It was observed that the CAT activity showed an overall increase after 24 and 96 hours after the application of DEHP. SOD and GST activities increased after 96 hours. In light microscope examination of the model organism; hemolymphatic filled hemolymph filled with hemolymphatic duct, hemolymphatic reduction or hemolymphatic ducts were observed especially in the Gammarus pulex gills. After 96 hours, gill collapse and hyperplasia were determined. As a result, it is suggested that changes in SOD, CAT and GST can potentially be used as sensitive biomarkers for risk assessment in the environment and DEHP caused increased immunoreactivity in Gammarus pulex depending on increased application doses and application times.