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Objective:Phthalates （PAEs） are common environmental endocrine disruptors. In this study， the effects of oxidative stress on liver and nutrient metabolism were determined in male diabetic rats exposed to di-2-ethylhexyl phthalate （DEHP）， and the mechanism of DEHP toxicity was explored. Methods:Thirty-two SPF male Wistar rats aged five weeks， weighing 150-170 g， were fed adaptively for one week to establish the model of type 2 diabetes. The model was established by intraperitoneal injection of streptozotocin （STZ） （25 mg/kg） after feeding with high sugar and high fat diet for four weeks. Second STZ injection was given two days later. The model was considered to be established successfully when the random blood glucose level was found to be higher than 16.7 mmol/L in two separate tests. Twenty diabetic rats were then randomly divided into four groups， including control group （corn oil）， 100， 300 and 900 mg/kg DEHP groups. The rats were treated with DEHP by gavage （5 mL/kg） once a day for 30 days. They were fed with normal diet during the treatment period. Caudal venous blood was collected on the 1st， 14th， and 28th days to measure the random blood glucose level. The changes of glucose tolerance were determined by oral glucose tolerance test on the 29th day. Fasting blood glucose （FPG） was measured on the next day of the last exposure. After the rats were anesthetized with pentobarbital and killed， the liver was weighed， the liver coefficient was calculated and the liver pathological section was made. Blood was taken from the abdominal aorta. The levels of aspartate aminotransferase （AST）， alanine aminotransferase （ALT）， alkaline phosphatase （ALP）， triacylglycerol （TG） and albumin （ALB） in serum were measured by spectrophotometry， and the levels of insulin， glutathione （GSH）， H2O2， malondialdehyde （MDA） and superoxide dismutase （SOD） in fasting serum were measured by radioimmunoassay. Results:There was no significant difference in body weight and random blood glucose in the type 2 diabetic rats exposed to different concentrations of DEHP （all P>0.05）. At each time point of the glucose tolerance curve， the blood glucose value of the exposure groups was higher than that of the control group. A "false plateau period" appeared after the blood glucose value reached or exceeded the upper limit at 15 minutes， and the blood glucose level in each group was higher than that of the control group at 120 minutes. The liver organ coefficient of 300 and 900 mg/kg DEHP groups was higher than that of the control group （both P<0.01）， and the liver organ coefficient was positively correlated with the exposure concentration of DEHP （r=0.80，P<0.000 1）. Under the microscope， the liver cells in diabetic rats were swollen， the cytoplasm was light stained， and there were vacuoles in the cells. The serum ALP level in diabetic rats of 900 mg/kg DEHP group was significantly higher than that in the control group （P<0.01）. The serum ALP level was positively correlated with the concentration of DEHP （r=0.75， P<0.01）. The serum MDA level in diabetic rats of 300 mg/kg and 900 mg/kg DEHP groups was significantly higher than that of the control group （both P<0.01）， and the serum MDA level was positively correlated with the concentration of DEHP （r=0.84， P<0.000 1）. The serum SOD level of 900 mg/kg DEHP group was significantly higher than that of control group （P<0.01）. Conclusion:DEHP exposure could lead to liver damage， abnormal glycolipid metabolism， and increase the level of oxidative stress and antioxidant level in male diabetic rats， but did not show a significant effect on insulin resistance.
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Objective To provide reference to food safety supervision and management by analyzing the characteristics and trends of food safety incidents reported by media in 2013 in china.Methods Data were collected and collated from food safety incidents reported by printed media,major web portals,news websites and public opinion reports of the government during 2013.1.1 and 2013.12.31 with their occurrence characteristics and trends studied.Results Food safety incidents reported by media added up to 740 cases during 2013.1.1 and 2013.12.31 in China,of which the most reported was in Guangdong province,with 130accounting for 17.6% of the total,next followed by Shandong,Zhejiang and Jiangsu provinces.The number of incidents reported by months did not show an obvious trend,yet incidents occurred more frequently in September and October.As for related food types,164 incidents (22.2% of the total) related to poultry meat and meat products;snacks were involved in 53 incidents,accounting for 7.2% of the total.Nearly 2/3 of the incidents resulted from problems of production and processing links,among which 13.9% were from the production of primary agricultural products,10.2% and 8% from sales &circulation,and catering consumption respectively.About 40% of the food safety issues reported by media were related to circulation.As for nature of the incidents,pathogenic micro organisms,pesticides or veterinary drug residues and excessive contents of heavy metals was 22%,followed by processing with non-food raw materials or adding non-food chemicals.31.8% of hazards or potential hazards in reported food safety incidents during 2013 were food additives and illegal additives.Conclusion Food safety incidents involving meat,meat products and snacks had a relatively higher occurrence.Food production,processing and circulation became high risk links in food safety issues.Pathogenic micro organisms,pesticides or veterinary drug residues,excessive contents of heavy metals and violation of food additives management were relatively serious problems.Chemical hazard was one of the major hazards in food safety issues.
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<p><b>OBJECTIVE</b>Consuming phthalates may be due to the presence of food contact materials, such as plastic containers. In this study, we investigated the association between plastic container use and phthalate exposure in 2,140 Shanghai adults.</p><p><b>METHODS</b>Participants completed a questionnaire on the frequency of using plastic containers in different scenarios in the previous year (e.g., daily, weekly) and on the consumption of plastic-packaged foods in the previous three days (yes or no). Urinary phthalate metabolites were used to assess the association between phthalate exposure and the use of plastic containers.</p><p><b>RESULTS</b>The metabolites of di-(2-ethylhexyl) phthalate (DEHP) were the most frequently detected in urine. The results revealed that phthalate exposure was associated with consumption of plastic-packaged breakfast or processed food items in the previous three days. The consumption of these two food items had strong synergistic effects on increasing urinary concentrations of most phthalate metabolites.</p><p><b>CONCLUSION</b>Our results of plastic-packaged breakfast and processed food may be explained by the use of flexible plastic containers, indicating the importance of risk assessment for the application of flexible plastic containers.</p>
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Adult , Humans , China , Cities , Data Collection , Phthalic Acids , Metabolism , Urine , Plastics , ChemistryABSTRACT
Five compounds (tenuifoliside C, tenuifoliside D, telephiose A, telephiose C and polygalaxanthone III) from polygala tenuifolia wild were incubated together with CYP probe substrate in human liver microsomes to investigate the inhibitory effect towards CYP450 enzyme. Phenacetin (CYP1A2), coumarin (CYP2A6), paclitaxel (CYP2C8), diclofenac (CYP2C9), S-mepheriytoin (CYP2C19), dextromethorphan (CYP2D6), chlorzoxazone (CYP2E1), midazolam (CYP3A) were selected as the isoforfn specific substrate. And the formation of paracetamol, 7-hydroxycoumarin, 6alpha-hydroxy paclitaxel, 4'-hydroxydiclofenac, dextrorphan, 6-hydroxychlorzoxazone, 1'-hydroxymidazolam, 4'-hydroxymephenytoin were detected respectively to measure the effect towards CYP450 by high-pressure liquid chromatography (HPLC). The result shows that five compounds from polygala tenuifolia willd significantly inhibit chlorzoxazone 6-hydroxylation catalyzed by CYP2E1, while showed no effect towards CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A. And IC50 value was 38.73, 54.14, 61.77, 62.22, 50.56 micromol x L(-1), respectively.