Endoplasmic reticulum stress and pro-inflammatory responses induced by phthalate metabolites monoethylhexyl phthalate and monobutyl phthalate in 1.1B4 pancreatic beta cells.

In recent years, phthalates and their metabolites have been associated with metabolic diseases such as diabetes mellitus. To investigate the effects of phthalate metabolites exposure on insulin production and release, 1.1B4 pancreatic beta cells were treated with different concentrations (0.001-1000 µM) of monoethylhexyl phthalate (MEHP) and monobutyl phthalate (MBP). For such purpose, the 1.1B4 cells were evaluated for their viability, apoptosis rate, lysosomal membrane permeabilization (LMP), mitochondrial membrane potential (ΔΨm), oxidative stress, ER stress status, in addition to their secretory functions. MEHP, not MBP, exhibited a notable reduction in metabolic viability, particularly at higher concentrations (500 and 1000 µM) following 24-hour exposure. Similarly, both MEHP and MBP induced decreased metabolic viability at high concentrations after 48- and 72-hour exposure. Notably, neither MEHP nor MBP demonstrated a significant impact on apoptosis rates after 24-hour exposure, and MBP induced mild necrosis at 1000 µM concentration. Cell proliferation rates, indicated by PCNA expression, decreased with 10 and 1000 µM MEHP and 0.1 and 10 µM MBP exposures. LMP analysis revealed an increase in 1000 µM MBP group. Exposure to 0.001 µM of both MEHP and MBP significantly reduced cellular glutathione (GSH) levels. No significant change in intracellular reactive oxygen species (ROS) levels and ΔΨm was observed, but MBP-exposed cells exhibited elevated levels of lipid peroxidation. Functional assessments of pancreatic beta cells unveiled reduced insulin secretion at low glucose concentrations following exposure to both MEHP and MBP, with concurrent alterations in the expression levels of key proteins associated with beta cell function, including GLUT1, GCK, PDX1, and MafA. Moreover, MEHP and MBP exposures were associated with alterations in ER stress-related pathways, including JNK, GADD153, and NF-κB expression, as well as PPARα and PPARγ levels. In conclusion, this study provides comprehensive insights into the diverse impacts of MEHP and MBP on 1.1B4 pancreatic beta cells, emphasizing their potential role in modulating cell survival, metabolic function, and stress response pathways.

Comparative developmental toxicity evaluation of di- n-hexyl phthalate and dicyclohexyl phthalate in rats.

To investigate the effects of di- n-hexyl phthalate (DHP) and dicyclohexyl phthalate (DCHP) on the development of fetus and placenta in utero, pregnant rats were exposed to DHP or DCHP at dosages of 0, 20, 100, and 500 mg/kg bw/day, by gavage, on gestational days 6-19. Anogenital distance (AGD) and AGD-body weight1/3 ratio of female fetuses decreased in all treatment groups in a non-dose-response way. The ossification centers of bones and the intensity of Alizarin red stain of the fetuses decreased in all treatment groups. The white blood cell levels of fetuses in DHP and DCHP exposed groups increased at all dosages. Mean cell hemoglobin, hemoglobin concentrations, and hemoglobin levels of all DHP and DCHP treated male and female fetuses were reduced. Histopathologic changes (hemorrhage in labyrinth, degeneration of spongiotrophoblast, hemorrhage, decreased and irregular vessel formation, and edema in the basal zone) were observed in placentas at high dosages of DHP and DCHP. In contrast, there was no change in weight gain of dams in DHP and DCHP exposed groups compared to control, but resorption rate, reduced fetal weight, delayed ossification, placental disruption, and hematologic parameters clearly indicated that in utero DHP and DCHP exposure resulted in intrauterine growth retardation in rats.

The toxicological effects of bisphenol A and octylphenol on the reproductive system of prepubertal male rats.

The aim of the present study was to assess and compare the individual adverse effects of bisphenol A (BPA) and octylphenol (OP) on the reproductive system of prepubertal male rats. Rats were exposed to BPA and OP at doses of 125 and 250 mg/kg/day, by gavage, for 90 days. At the end of the study, the testes, epididymis, prostate gland, and seminal vesicle were removed and examined histopathologically. Also, 3-ß-hydroxysteroid dehydrogenase expressions were analyzed and serum testosterone and luteinizing hormone (LH) levels were measured. Sperm head count of caput epididymis was performed using a hemocytometer. Seminiferous and epididymal round tubules were evaluated for tubule diameter, lumen diameter, and height of tubule epithelium. There were significant increases in relative testes weights in BPA125, OP125, and OP250 groups compared with the control. Atrophic tubules, pyknotic tubules, combined tubules, congestion, vacuolization of Sertoli cell, cell debris in the lumen, tubules without sperm, and degeneration of tubules were noted in the tissue specimens obtained from the treatment groups compared with the control group. Sperm head counts were decreased in all treatment groups except for the low-dose BPA group. Testosterone (T) levels decreased in the BPA and high-dose OP treatment groups. LH levels increased in BPA treatment groups and the low-dose OP treatment group and decreased in the high-dose OP group. Epithelial height of high-dose BPA and OP treatment groups increased compared with the control group. Furthermore tubular height of low-dose BPA and high-dose OP groups increased with respect to control levels. In the OP250 treatment group, thyroxine hormone level was increased compared to other groups. Also, in the OP125 treatment group, triiodothyronine hormone level was increased compared with other groups. The results of this study showed that BPA and OP affect the steroidogenic enzyme expression and T production in Leydig cells. In conclusion, BPA and OP have adverse effects on the male reproductive system of prepubertal rats.

An in vivo assessment of the genotoxic potential of bisphenol A and 4-tert-octylphenol in rats.

Bisphenol A (BPA) and octylphenol (OP) are industrial chemicals used in the manufacture of polycarbonate plastics, epoxy resins, and non-ionic surfactants. In the present study, we investigated the possible in vivo genotoxic effects of these compounds in rats using single-cell gel electrophoresis, the so-called comet assay. Adult male Wistar albino rats were divided randomly into six groups as follows: BPA125 (received 125 mg/kg bw BPA; n = 6), OP125 (received 125 mg/kg bw OP; n = 6), BPA250 (received 250 mg/kg BPA; n = 6), OP250 (received 250 mg/kg bw OP; n = 6), control (n = 5), and MMS (positive control group that received methyl methanesulfonate; n = 3). Both BPA and OP were orally administrated for 4 weeks. Controls were orally inoculated with corn oil for 4 weeks as well. Comet parameters including tail length and tail moment were evaluated for possible genotoxic effects. There were no significant differences in the OP125 and in the BPA125 compared with the control group, regarding tail length and tail moment (P > 0.05). However, there were significant differences in the OP250 and in the BPA250 compared with the control group, regarding tail length and tail moment (P < 0.05 and P < 0.01, respectively). The genotoxic potential of BPA and OP was investigated in vivo; there is a need for further studies exploring further mechanisms of the genotoxic potential of these chemicals in vivo.

Influence of vitamin C on bisphenol A, nonylphenol and octylphenol induced oxidative damages in liver of male rats.

The purpose of this study was to investigate whether bisphenol A (BPA), nonylphenol (NP) and octylphenol (OP) induce oxidative stress in the liver of male rats and co-administration of vitamin C can prevent any possible oxidative stress. Wistar male rats were divided into seven groups (vehicle, BPA, NP, OP, BPA+C, NP+C, OP+C). BPA, OP and NP groups (25 mg kg(-1)day(-1)) were administered orally to rats three times a week for 50 days. In BPA+C, NP+C, OP+C groups, vitamin C (60 mg kg(-1)day(-1)) was administered along with BPA, OP and NP (25 mg kg(-1)day(-1)) treatments. Aspartate transaminase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH), thiobarbituric acid-reactive substances (TBARS) were increased, glutathione (GSH) levels were decreased in treatment groups. AST, ALT, LDH and TBARS levels were increased whereas GSH levels were decreased in BPA+C, NP+C and OP+C groups compared to BPA, NP, and OP groups, respectively. Hepatic necrosis and congestion were observed in livers of rats treated. In conclusion, the present results demonstrate that BPA, NP, and OP cause oxidative damage by disturbing the balance between ROS and antioxidant defenses system in liver of male rats. Vitamin C co-administration along with BPA, NP, OP aggravates the damage in liver of male rats.