Adverse effect of DEHP exposure on the serum insulin level of Balb/c mice

Di(2-ethylhexyl) phthalate (DEHP) is a common indoor pollutant in the world, which may cause lots of harmful effects in human including diabetes according to epidemiological studies. To explore the underlying role of DEHP in diabetes-like symptoms, Balb/c mice were chose to be the experimental animals in this paper. They were separated as eight groups as follows: (1) saline+normal diet (vehicle control), (2) 10 mg/kg.day DEHP+normal diet, (3) 50 mg/kg.day DEHP+normal diet, (4) 250 mg/kg.day DEHP+normal diet, (5) streptozotocin (STZ)+high fat diet (diabetes model), (6) 10 mg/kg.day DEHP+ STZ+high fat diet, (7) 50 mg/kg.day DEHP+STZ +high fat diet, (8) 250 mg/kg.day DEHP+STZ+high fat diet. The biomarkers of this experiment include four groups: (1) general indicates: body weight and drinking water, (2) blood biomarkers: serum insulin and fasting glucose, (3) pathological examination: pancreas section and kidney section, and (4) biomarkers of oxidative stress: reactive oxygen species (ROS) and malondialdehyde (MDA) in liver cells. Our study results demonstrate that: (1) at our treatment levels DEHP cannot directly induce diabetes, but reduce serum insulin level in DEHP-exposed non-STZ-treated animals, (2) pathological examination finds that these is a dose-dependent damage in the pancreas in DEHP- exposed STZ-treated groups, and (3) the oxidative mechanism may be involved in this pathological process.