Reproductive toxicity following in utero and lactational exposure to a human-relevant phthalate mixture in rats.

This rodent (Wistar rats) study examined reproductive effects of in utero/lactational exposure to a mixture of 6 antiandrogenic phthalates (PMix): diisobutyl phthalate, di-n-butyl phthalate, diisopentyl phthalate, butylbenzyl phthalate, di-2-ethylhexyl phthalate, and diisononyl phthalate. The PMix was defined based on exposure data from pregnant women in Brazil. Experimental groups were established by extrapolating the estimated human dose to rats (0.1 mg/kg/day), followed by up to 3 additional doses corresponding to 5, 1000, and 5000 times the starting rat dose: 0 (control), 0.1, 0.5, 100, and 500 mg/kg/day. The fetal experiment assessed gestational exposure effects on fetal gonads, whereas the postnatal experiment evaluated reproductive parameters in males and females after in utero and lactational exposure. Prenatal exposure decreased fetal testicular testosterone production at 0.5 and 500 mg/kg/day. PMix 500 also reduced mRNA expression of steroidogenesis-related genes, upregulated transcript expression of the retinoic acid-degrading enzyme Cyp26b1, and increased multinucleated gonocytes incidence in fetal testes. Postnatal assessment revealed antiandrogenic effects at the highest dose, including reduced anogenital distance, nipple retention, and decreased weight of reproductive organs. Early puberty onset (preputial separation) was observed at the lowest dose in males. In contrast, females did not show significant changes in fetal and adult endpoints. Overall, the PMix recapitulated early and late male rat phthalate syndrome phenotypes at the highest dose, but also induced some subtle changes at lower doses, which warrant confirmation and mechanistic assessments. Our data support the use of epidemiologically defined mixtures for exposure risk assessments over traditional toxicological approaches.

The Analgesic Dipyrone Affects Pregnancy Outcomes and Endocrine-Sensitive Endpoints in Female and Male Offspring Rats.

Dipyrone is an analgesic and antipyretic drug commonly used in many countries. Although generally not recommended during pregnancy, it is known that many women use dipyrone during the gestational period. In this study, we investigated the endocrine and reproductive effects of dipyrone in female and male offspring rats exposed in utero from gestational days 10-21. Pregnant rats were treated with dipyrone at 25, 75, and 225 mg/kg/day via oral gavage. Developmental landmarks-anogenital index (AGI), number of nipples, vaginal opening, first estrus, and preputial separation-were evaluated in the offspring. Reproductive parameters, including estrous cycle regularity, daily sperm production, weight and histopathology of reproductive organs, steroid hormone levels, and gene expression of selected markers of reproductive function were assessed at adulthood. At the highest dose, dipyrone induced a significant increase in postimplantation losses/fetal death and delayed parturition in dams. Offspring exposed in utero to the highest dose also exhibited significant changes in some early life markers of endocrine disruption, in particular increased AGI in females, indicating a proandrogenic effect, and increased rate of retained nipples in males, indicating an antiandrogenic response. No changes were observed in markers of puberty onset or reproductive parameters at adulthood. These results suggest that exposure to therapeutically relevant doses of dipyrone may induce mild endocrine disruptive effects that can be detected in late pregnancy and early life. Such effects may be relevant considering dipyrone use by pregnant women and the possibility of coexposures with other endocrine disruptors.

Effects of diisopentyl phthalate exposure during gestation and lactation on hormone-dependent behaviours and hormone receptor expression in rats.

Phthalates are found in different plastic materials, such as packaging, toys and medical devices. Some of these compounds are endocrine disruptors, comprising substances that are able to induce multiple hormonal disturbances and downstream developmental effects, including the disruption of androgen-dependent differentiation of the male reproductive tract and changes in pathways that regulate hormone-dependent behaviours. In a previous study, metabolites of diisopentyl phthalate (DiPeP), a potent anti-androgenic phthalate, were found in the urine of Brazilian pregnant women. Therefore, the present study aimed to evaluate the effects of DiPeP exposure during critical developmental periods on behaviours controlled by sex hormones in rats. Pregnant Wistar rats were treated with DiPeP (1, 10 or 100 mg kg day-1 ) or canola oil by oral gavage between gestational day 10 and post-natal day (PND) 21. Male offspring were tested in a behavioural battery, including the elevated plus maze task, play behaviour, partner preference and sexual behaviour. After the behavioural tests, the hypothalamus and pituitary of these animals were removed on PND 60-65 and PND 145-160 to quantify gene expression for aromatase, androgen receptor (Ar) and oestrogen receptors α (Esr1) and ß (Esr2). Male rats exposed to 1 and 10 mg kg day-1 DiPeP displayed no preference for the female stimulus rat in the partner preference test and 1 mg kg day-1 DiPeP rats also showed a significant increase in mount and penetration latencies when mated with receptive females. A decrease in pituitary Esr1 expression was observed in all DiPeP treated groups regardless of age. A reduction in hypothalamic Esr1 expression in rats exposed to 10 mg kg day-1 DiPeP was also observed. No significant changes were found with respect to Ar, Esr2 and aromatase expression in the hypothalamus. These results suggest that DiPeP exposure during critical windows of development in rats may induce changes in behaviours related to mating and the sexual motivation of males.

In Utero and Lactational Exposure to Diisopentyl Phthalate Induces Fetal Toxicity and Antiandrogenic Effects in Rats.

A previous study has demonstrated exposure of Brazilian pregnant women to diisopentyl phthalate (DiPeP), which reduces fetal rat testosterone production in a dose-responsive manner. In this study, we examined gene expression of steroidogenic proteins in rat fetal testes and investigated the effects of in utero and lactational DiPeP exposure on male rat reproductive development and function. For the prenatal experiment, we orally exposed pregnant Wistar rats to DiPeP or di-n-butyl phthalate (reference phthalate) at 0, 125, 250, and 500 mg/kg/day from gestation day 14-18 and the fetal testis was evaluated for transcript expression of Star, Cyp11a1, Cyp17a1, Cyp19a1, Insl3, Ar, Esr1, Esr2, and Gper1 by real-time quantitative PCR (RT-qPCR). Diisopentyl phthalate lowered mRNA levels of key steroidogenic proteins, lending support to the previously reported reductions in fetal testosterone production. Diisopentyl phthalate also lowered fetal testis transcript levels of Insl3 and changed gene expression of some steroid hormones receptors. For the postnatal experiment, pregnant rats were exposed orally to vehicle (canola oil) and 4 DiPeP doses (1, 10, 100, and 300 mg/kg/day) between gestation day 10 and postnatal day 21. Diisopentyl phthalate induced a range of reproductive and antiandrogenic effects that are typical of the rat phthalate syndrome, including reduced anogenital distance at the highest dose, reduced weight of seminal vesicles at 10 mg/kg/day and above, and testicular morphological and functional changes. Signs of fetal toxicity were observed at the highest dose. Together, our results indicate that DiPeP, a compound relevant to the human exposure scenario, is one of the most active antiandrogenic phthalates.

Anchietea pyrifolia A. St.-Hil. as a Cardiovascular-Endowed Species: A Whole-Biological Investigation.

Although leaves of Anchietea salutaris are used in Brazilian traditional medicine, there is no available data in the literature proving its efficacy and safety. Thus, the aim of the study was to perform a meticulous botanical, phytochemical, toxicological, and pharmacological investigation of A. salutaris in Wistar rats. At first, a morphoanatomical characterization of Anchietea pyrifolia leaves and stems was performed. Then, a purified infusion (ethanol-soluble fraction obtained from A. pyrifolia [ESAP]) was obtained followed by its chemical profile elucidation. Furthermore, an acute toxicity test was performed, and the acute and prolonged diuretic and hypotensive effects were also evaluated in Wistar rats. Finally, the vasodilatory responses of ESAP in mesenteric vascular beds were investigated. The main secondary metabolites identified from ESAP were O-glycosylated flavonoids, chlorogenic acids, and phenylpropanoic acid derivatives. ESAP did not promote any toxic effects in female rats nor increased urinary excretion in male rats after a single exposure. However, ESAP significantly reduced renal elimination of sodium, potassium, and chloride after prolonged treatment. An ESAP highest dose promoted significant acute hypotension without affecting blood pressure levels after prolonged use. Furthermore, its cardiovascular effects seem to be related with the calcium-activated potassium channel activation in resistance vessels.