Chronic toxicity of diethyl phthalate—A three generation lactational and gestational exposure study on male Wistar rats (original) (raw)
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Environmental science and pollution research international, 2016
With the limited but ongoing usage of di-n-butyl phthalate (DBP) as plasticizer, the health effects of both phthalate and its alternatives are far from being understood. Multigenerational effects of phthalates were evaluated in rats upon exposure to DBP, aiming to provide some evidences about its potential in causing developmental teratogenicity. Gestational rats were exposed to DBP (500 mg/kg bw/day) and control groups with olive oil. On the 18th day of gestation, fetuses (F1) isolated from a few dams were subjected to prenatal screening, and the other rats were allowed to litter, and later postnatal screening was made. DBP-toxicated (F1) rats were crossed and reared up to three generations (F2 and F3) by adopting the same experimental design. A considerable decrease in the weight of placenta, low number of corpora lutea and increased resorptions, and pre- and postimplantation loss were observed in F1, F2, and F3 generations. Further, there was a decrease in the number of live birt...
Developmental toxic potential of di-n-propyl phthalate administered orally to rats
Journal of Applied Toxicology, 2011
The objective of this study was to evaluate the developmental toxic potential of di-n-propyl phthalate (DnPP) in rats. Pregnant Sprague-Dawley rats were given DnPP at doses of 0 (olive oil), 0.5, 1 and 1.5 g kg -1 per day, by gavage, on gestation days 6-20. Benchmark doses were calculated for the effects of DnPP on fetal weight and anogenital distance of the male fetuses. Maternal body weight gain was significantly reduced at 1.5 g kg -1 per day, over gestation days 6-9. DnPP-treated dams also showed a statistically significant increase in liver weight and a mild but statistically significant peroxisomal enzyme induction at 1 or 1.5 g kg -1 per day. Male and female fetal body weights were significantly reduced at 1.5 g kg -1 per day. There was a statistically significant decrease in the anogenital distance of the male fetuses at 1 and 1.5 g kg -1 per day, and three males (of 75) showed malpositioned testis at the high dose. The mean percentage of fetuses per litter with cervical and thoracic rudimentary ribs was significantly increased at 1 and 1.5 g kg -1 per day. Delayed ossification was seen at 1 g kg -1 per day (phalanges) and 1.5 g kg -1 per day (hyoid, sternebrae, and phalanges). No treatment-related effects on prenatal viability or on fetal external or visceral malformations or variations were observed at any dose. Thus, there was no evidence of teratogenicity up to the high dose of 1.5 g kg -1 per day. The no-observed-adverse-effect level (NOAEL) for developmental toxicity was 0.5 g kg -1 per day.
Reproductive Toxicology, 2010
Phthalates are environmental contaminants used in the production of plastics, cosmetics and medical devices. Studies on the effects of phthalates on female reproductive health are particularly sparse and mostly restricted to high-dose exposure in rats. In the present study, pregnant rats were treated with 100 mg/kg-d of di-η-butyl-phthalate (DBP) or only the vehicle (control group), from GD 12 to GD 20 for evaluation of reproductive outcomes and fetal gonads analysis (F0), and from GD 12 to PND 21 to evaluate reproductive development and function on F1 female offspring. Results showed that all parameters were comparable between groups, although there was a significant increase in the fetal weight after DBP exposure. However, the body weight at birth was normal. Based on these data we can conclude that, in these experimental conditions, DBP did not disturb the reproductive development or function of female rats.
Journal of Immunotoxicology, 2005
Di-(2-ethylhexyl)phthalate (DEHP) helps provide flexibility to plastic products including food containers and medical IV devices. Age-based sensitivity to DEHP-induced immunotoxicity was compared in female CD strain rats following administration for 16 consecutive days in utero vs. adult exposure. Pregnant and nonpregnant rats received 0, 37.5, 75, 150, or 300 mg/kg/day of DEHP in soybean oil daily by oral gavage. In pregnant animals, this corresponded to days 6-21 of gestation. In exposed offspring, anogenital distance (AGD) was measured at one and three weeks of age. For a subset of offspring, immune assessment was conducted at 5 weeks of age following KLH immunization at 3 and 4 weeks. KLH immunizations occurred in remaining offspring at 11 and 12 weeks with immune assessment at 13 weeks. Nonpregnant adults were immunized concurrently with adult offspring and underwent immune assessment 13 weeks post-DEHP exposure. Litter size, sex ratio, and 1-week body weights were unaffected by treatment. However, AGD was altered at both ages assessed. Three-week (but not 5week) body weights were elevated in exposed offspring. Immune organ weights, thymus histology, antibody levels (IgG and IgE), DTH reaction to KLH, total and differential leukocyte counts, ex vivo cytokine production (IL-2,-4,-10,-12, interferon-gamma), as well as TNF-alpha and nitric oxide production by macrophages were not altered by treatment at any age. Flow cytometry analysis of splenocytes showed no differences during the juvenile assessment. In conclusion, in utero exposure of female rats to DEHP alters some developmental parameters (i.e., AGD) but has no persistent effect on the immune system based on the assessment parameters. Adult female rats also had no detectable immune alteration following similar exposures.
Toxicological Sciences, 2009
In the rat, some phthalates alter sexual differentiation at relatively low dosage levels by altering fetal Leydig cell development and hormone synthesis, thereby inducing abnormalities of the testis, gubernacular ligaments, epididymis, and other androgen-dependent tissues. In order to define the dose-response relationship between di(2-ethylhexyl) phthalate (DEHP) and the Phthalate Syndrome of reproductive alterations in F1 male rats, Sprague-Dawley (SD) rat dams were dosed by gavage from gestational day 8 to day 17 of lactation with 0, 11, 33, 100, or 300 mg/kg/day DEHP (71-93 males per dose from 12 to 14 litters per dose). Some of the male offspring continued to be exposed to DEHP via gavage from 18 days of age to necropsy at 63-65 days of age (PUB cohort; 16-20/dose). Remaining males were not exposed after postnatal day 17 (in utero-lactational [IUL] cohort) and were necropsied after reaching full maturity. Anogenital distance, sperm counts and reproductive organ weights were reduced in F1 males in the 300 mg/kg/day group and they displayed retained nipples. In the IUL cohort, seminal vesicle weight also was reduced at 100 mg/ kg/day. In contrast, serum testosterone and estradiol levels were unaffected in either the PUB or IUL cohorts at necropsy. A significant percentage of F1 males displayed one or more Phthalate Syndrome lesions at 11 mg/kg/day DEHP and above. We were able to detect effects in the lower dose groups only because we examined all the males in each litter rather than only one male per litter. Power calculations demonstrate how using multiple males versus one male/litter enhances the detection of the effects of DEHP. The results at 11 mg/kg/day confirm those reported from a National Toxicology Program multigenerational study which reported no observed adverse effect levels-lowest observed adverse effect levels of 5 and 10 mg/kg/day DEHP, respectively, via the diet.
Toxicology, 2004
To investigate the influence of dibutyl phtalate (DBP) given in a soy-free rat chow on pre-pubertal development, 46 Long Evans female rats 2-month-old were divided into three experimental groups and fed three different chows: (1) control; (2) DP 0.61 g/kg chow (12 mg/kg rat/day); (3) DP 2.5 g/kg chow (50 mg/kg rat/day) for 2 months. While under this treatment, they were mated and their offspring studied. Litter size and female:male ratio were recorded. At 14 days of age 6, male pups of each group were sacrificed and testis and thymus were excised and weighed. Pups were weaned at 22 days of age and continued into three experimental groups according to diet. From day 22 onwards, vaginal opening, occurrence of first estrous, and pre-putial separation were recorded. Results: The percent of pregnancies showed a marked decrease in group 3, while no difference was observed between groups 1 and 2. Sex prevalence and litter size were not affected by the different diets. Pup survival showed a decrease when mothers were fed diet 2, but it was similar in diets 1 and 3. Pup weights on day 2 showed an evident (P < 0.05) reduction in groups 2 and 3, the decrease being more marked (P < 0.001) in group 3. On day 6, pups of group 2 showed lower weights (P < 0.01) as compared with the other groups. Weight gain was significantly higher in pups of group 3. Eye opening was not affected by the different diets. Fourteen-day-old male pups' relative weight of thymus and testis showed a decrease in animals whose mothers had been fed diets 2 and 3. Vaginal opening and occurrence of first estrous showed an evident delay (P < 0.05; P < 0.01) in females fed diets 2 and 3. Significant differences (P < 0.001) in pre-putial separation were observed between treated and untreated groups. Conclusion: Offspring pre-pubertal development seems to be affected by oral intake of DBP by their mothers during pregnancy, the effects being more evident in the reproductive development of male pups.
Environmental Toxicology and Pharmacology, 2006
Polychlorinated biphenyls (PCBs) are persistent environmental pollutants and known to act as xenoestrogens. PCBs and diethyl phthalate (DEP) are ubiquitous environmental pollutants because both are used as plasticizers and in various other industrial applications. Therefore, a study was undertaken to evaluate the interactive toxicity of DEP and PCBs in young female Wistar rats. Healthy young female albino rats of Wistar strain weighing 100 g (7-8 weeks old) were randomly assigned to five groups of six each. Group I female rats were fed on normal diet and water ad libitum. Group II female rats were maintained on normal diet mixed with corn oil at 16.5 mg/kg diet/day and 0.94 mg/kg body weight/day as oil control. Groups III and IV female rats were given Clophen A60 and DEP dissolved in corn oil mixed with the diet at 50 mg/(kg diet day), which is approximately equal to 2.85 mg/(kg body weight day), individually to each group. Group V female rats received a mixture of DEP and Clophen A60, each dissolved in corn oil mixed with the diet at 50 mg/(kg diet day), which is approximately equal to 2.85 mg/(kg body weight day). Treatment was carried out for 150 days and after the completion of treatment, serum and liver enzymes and other biochemical parameters in the serum and liver were assessed. Liver weight to body weight ratio showed significant increase in Clophen A60 and Clophen A60 + DEP treated rats. In the three treated groups, there was significant decrease in liver glutathione (GSH) and glutathione reductase (GR). Alanine amino transferase (ALT) was significantly increased in the liver of the three treated groups and in the serum of Clophen A60 and DEP alone treated groups and significant decrease only in the serum of Clophen A60 + DEP treated rats. Significant increase in liver and serum lactate dehydrogenase (LDH) and acid phosphatase (ACP) activity was observed in the three treated groups. Alkaline phosphatase (ALP) activity was significantly increased only in the serum of the Clophen A60 and Clophen A60 + DEP treated rats, whereas significant decrease in the serum and liver of DEP alone treated rats was observed. Aspartate aminotransferase (AST) activity and cholesterol levels were highly significant in the liver and serum of DEP treated rats. In addition, cholesterol level was significantly increased in the liver and serum of Clophen A60 treated rats and only in the liver of Clophen A60 + DEP treated rats. Succinate dehydrogenase (SDH) activity was significantly increased in the liver of Clophen A60 and Clophen A60 + DEP treated rats and highly significant increase in the serum of Clophen A60 + DEP treated rats. There was significant increase in triglyceride levels in the liver and serum of Clophen A60 and Clophen A60 + DEP treated rats, whereas significant increase in triglyceride levels in the serum of DEP alone treated rats was observed. Glycogen levels were significantly increased in the liver of Clophen A60 + DEP treated rats, whereas serum glucose levels showed significant decrease, but in Clophen A60 alone treated rats showed significant increase in liver glycogen and serum glucose, whereas DEP alone treated rats showed significant increase in only serum glucose levels. Lipid peroxidation was increased in the liver of DEP treated rats, which was highly significant, compared to significant increase in Clophen A60 and Clophen A60 + DEP treated rats. Histology of liver showed severe vacuolation, loss of hepatic architecture and granular deposits in the hepatocytes of DEP and Clophen A60 + DEP treated rats, whereas in Clophen A60 alone treated rats, hepatocytes showed hyper pigmentation mild loss of hepatic architecture in centrilobular and periportal area.
Neurotoxicology and Teratology, 2012
Phthalates are industrial chemicals widely used in consumer products, plastics and children toys, and the risk of exposure to phthalates, especially prenatal exposure, is a growing concern justifying the development of an animal model to better understand their effect. The present study was designed to evaluate the suitability of a chick model for phthalate DEHP teratogenicity and neurobehavioral teratogenicity, a model which is simple and devoid of potential confounding factors such as maternal toxicity, maternal-fetal unit and maternalneonatal interactions; major findings were confirmed in the DBP study. Prehatch exposure to DEHP in doses ranging from 20 to 100 mg/kg, reduced the percent hatching from 80% in control eggs to 65%, and increased late hatchings from 12.5% in control eggs to 29.4%. In addition it induced developmental defects characterized by an opening or weakening of abdominal muscles allowing internal organs to protrude externally with or without a sac, omphalocele or gastroschisis, respectively. The effect was dose dependent ranging from 8% with DEHP (20 mg/kg) to 22% (100 mg/kg). Similar treatment with DBP 100 mg/kg has reduced percentage hatching to 57% and increased late hatching to 37.5%, with a 14% increase in gastroschisis. Biochemical evaluation revealed elevated levels of alkaline phosphatase, which reflects non-specific toxicity of DEHP at such a high dose. Behavioral evaluation using an imprinting test and locomotor activity on chicks pretreated with DEHP (100 mg/kg) has shown an abolishment of imprinting performance from the control (0.65) preference ratio. DNA damage measurements of the metabolite 8-hydroxydeoxyguanosine (8-OH-dG) in blood samples showed an increase of 39.7% after prehatch exposure to phthalates. This was statistically significant for DEHP and indicates genetic toxicity, since part of the teratogenic activity is associated with oxidative stress and DNA damage.
Reproductive Toxicology, 2003
Di(2-ethylhexyl) adipate (DEHA) has replaced the phthalates in thin plasticized polyvinyl chloride films used for food packaging, mainly because some phthalates induce testis toxicity and antiandrogenic effects. A dose-range finding study followed by a dose-response/effect study in Wistar rats investigated whether pre-and postnatal DEHA doses of 0, 800, or 1200 mg/kg/day body weight and doses of 0, 200, 400, or 800 mg/kg/day (main study) elicited developmental toxicity including antiandrogenic effects. In the main study, DEHA induced a prolonged gestation period (800 mg/kg/day) and a dose-related increase in postnatal death (400 and 800 mg/kg/day). DEHA also induced a permanent decrease in offspring body weight (800 mg/kg/day). No antiandrogenic endpoints were affected. We conclude that DEHA induced developmental toxicity and the NOAEL is 200 mg/kg. DEHA did not induce antiandrogenic effects similar to those of di(2-ethylhexyl) phthalate even though the chemical structures have similarities and the two chemicals have a common metabolite.