Effects of the in-utero dicyclohexyl phthalate and di-n-hexyl phthalate administration on the oxidative stress-induced histopathological changes in the rat liver tissue correlated with serum biochemistry and hematological parameters.

Phthalates are widely used as plasticizers in the industry and are found in cosmetics, food and drink packaging, drugs, toys, households, medical devices, pesticides, personal care products, and paints. Phthalates exert endocrine disrupting and peroxisome proliferator effects in humans and wildlife associated with the pathogenesis of various diseases, including diabetes, obesity, infertility, cardiovascular diseases, metabolic syndrome, and cancer. Since phthalates are metabolized in the liver, which regulates the body's energy metabolism, long or short-term exposure to the phthalates is associated with impaired glucose, lipid, and oxidative stress metabolisms contributing to liver toxicity. However, the impact of in-utero exposure to DHP and DCHP on liver metabolism has not been studied previously. Thus, in this study, we evaluated serum biochemistry parameters, hematological markers, histopathological changes, and oxidative and pentose phosphate pathway (PPP) metabolisms in the liver following in-utero DHP and DCHP administration, respectively, in male and female rats. We found increased relative and absolute liver weights and impaired triglyceride, alanine transaminase (ALT), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP) levels upon dicyclohexyl phthalate (DCHP) and di-n-hexyl phthalate (DHP). Histopathological changes, including congestion, sinusoidal dilatation, inflammatory cell infiltration, cells with a pyknotic nucleus, lysis of hepatocytes, and degeneration of hepatic parenchyma have been observed in the liver samples of DHP and DCHP dose groups. Moreover, increased glutathione s-transferase (GST), glucose 6-phosphate dehydrogenase (G6PD), and glutathione reductase (GR) activities have been found in the liver samples of DHP and DCHP-treated rats associated with impaired pentose phosphate pathway (PPP) and oxidative stress metabolism. First time in the literature, we showed that in-utero exposure to DHP and DCHP causes liver damage associated with impaired oxidative stress metabolism in male and female rats. Our data may guide researchers and governments to regulate and restrict phthalates in industrial products.

Low dose monoethyl phthalate (MEP) exposure triggers proliferation by activating PDX-1 at 1.1B4 human pancreatic beta cells.

Phthalate plasticizers used in a wide range of common plastic products are released into the environment and may pose a risk of increased incidence of type 2 diabetes. In this work, we studied the effects of monoethyl phthalate (MEP), the metabolite of diethyl phthalate, exposure on 1.1B4 human pancreatic beta cells at low doses (1-1000 nM). We showed that MEP treatment induced proliferation in 1.1B4 cells. Also PCNA protein expression levels were increased related to proliferation induction. It has been noted that phthalates can exert estrogen mediated response by interacting with ER. In our study 24 h MEP treatment decreased ERα protein expression level conversely it increased the same protein expression level after 72 h treatment. Also MEP treatment decreased ERß expression after 72 h at 1.1B4 cells. Our results further show that insulin content of 1.1B4 cells were increased with low dose MEP treatment. Along with our insulin content results, PDX- 1 expression levels were also increased at 1.1B4 cells with MEP treatment. These findings suggest that MEP acts as an estrogenic compound and PPARγ agonist at lower concentrations. Also it should be noted that PDX-1 may be a critical regulator of 1.1B4 cells treated with MEP.

Influence of in utero di-n-hexyl phthalate and dicyclohexyl phthalate on fetal testicular development in rats.

This study investigated the effects of di-n-hexyl phthalate (DHP) and dicyclohexyl phthalate (DCHP) on male reproductive development in utero. Pregnant rats were exposed to DHP and DCHP at doses of 0 (vehicle), 20, 100 and 500mg/kg/day, by gavage, on gestational days (GD) 6-19. A significant decrease in the anogenital distance (AGD) of male fetuses was observed at all doses of DHP and DCHP. The AGD/cube root of body weight ratio in male fetuses was also significantly reduced compared to control group. The litters with resorption, percentage of resorptions and inhibin B levels increased in treatment groups. Moreover, testosterone and MIS/AMH levels in all treatment groups decreased. Although FSH and inhibin B levels of male pups exposed to DHP and DCHP increased, FSH/inhibin B ratio decreased in treatment groups. Reduced testosterone production in response to DHP and DCHP exposure appeared to be related to changes in testosterone metabolism, as shown by decreased 3ß-HSD immunoexpression. The percentages of large Leydig clusters increased after exposure to DHP and DCHP in utero. Histopathological examination of the testis on GD20 revealed changes at all doses. Relative integrated immunodensities of 3ß-HSD, MIS/AMH, PCNA and AR decreased after DHP and DCHP exposures. Altered fetal Sertoli cell development and function may be caused by disrupted PMC function revealed by reduced AR production in these cells in treatment groups.

Developmental effects of prenatal di-n-hexyl phthalate and dicyclohexyl phthalate exposure on reproductive tract of male rats: Postnatal outcomes.

The present study is to investigate the effects of in utero di-n-hexyl phthalate (DHP) and dicyclohexyl phthalate exposure (DCHP) on the development of male reproductive tract at prepubertal, pubertal and adult stages. Pregnant rats were exposed to DHP and DCHP at doses of 0, 20, 100 and 500mg/kg/day, by gavage, on gestational days (GD) 6-19. Testosterone (T) levels of prepubertal rats diminished at high dose DHP and middle dose DCHP groups. MIS/AMH levels elevated in DHP and DCHP groups. T levels of pubertal rats decreased in low and high dose DHP and DCHP groups. Inhibin B levels of adult rats diminished in DCHP groups. Atrophic and amorphous tubules, spermatogenic cell debris, apoptotic cells, adherent tubules, Sertoli cell vacuolisation, prostatic atrophic tubules and prostatic intraepithelial neoplasia (PIN) were observed in the reproductive organs of treated animals at all developmental stages. There was an increase in immunoexpression of MIS/AMH in testes of treated rats. There were no changes in sperm head count but percentages of abnormal sperms increased. The diameters of seminiferous and epididymal tubules in treatment groups were significantly lower. This study shows that DHP and DCHP may have antiandrogenic effects on male reproductive development before and after birth.