| Abstrakt: |
Di (2-ethylhexyl) phthalate (DEHP), the most used plasticizer is known to have adverse effects on humans and other mammals, mainly causing impairment of hepatic and reproductive function. As DEHP is not easily biodegradable in the anaerobic conditions, it tends to get accumulated in the sediments and leaches into the water columns and hence can endanger the aquatic fauna. The present study focused on the hepatic and gonadal toxicity of adult female zebrafish due to chronic exposure of 21 days to 0.2 μg/L and 20 μg/L DEHP concentrations. Activity of liver function enzymes, viz. aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and the oxidative stress markers, viz. superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) were estimated to assess hepatotoxicity. AST enzyme activity was significantly increased in the experimental group exposed to 20 μg/L DEHP. Decreased levels of SOD, CAT and GSH were reported for both the exposure concentrations, indicating oxidative stress. Their liver tissue showed wider sinusoid spaces, shrunken hepatocytes with pyknotic nuclei, loss of hepatic cytoarchitecture, thickened bile ducts and steatosis. Atretic oocytes, underdeveloped cortical alveolar stage oocytes with collapsed chorion, irregularly shaped mature oocytes, accumulation egg debris of degenerating immature oocytes were observed in the ovary, indicating gonadal toxicity. Embryos exposed to both the concentrations of DEHP for 96 hpf showed morphological deformities such as altered body curvature, bent spine, yolk sac edema, pericardial edema and cerebral edema. Thus, it could be concluded that chronic exposure to DEHP even at its low concentrations can cause hepatic and gonadal toxicity in female zebrafish and it also has impact on the developmental stages. [ABSTRACT FROM AUTHOR] |
