Coadministration of active phthalates results in disruption of foetal testicular function in rats.

The reproductive effects of the coadministration of di-2-(ethylhexyl) phthalate (DEHP) and di-butyl phthalate (DBP) were studied in both foetal and adult male rat offspring exposed in utero. Pregnant Wistar rats were treated by oral gavage from gestation day 13 to 21 with vehicle control, 150 mg DEHP/kg body weight (bw)/day, 100 mg DBP/kg bw/ or a combination of the two compounds (DEHP 150 + DBP 100 mg/kg bw/day). An additional group of dams received 500 mg DBP/kg bw/day. A significant decrease in foetal testicular testosterone levels was observed in animals exposed to 500 mg DBP/kg/day or the phthalate mixture. Similarly, histological analysis of the foetal testis revealed that the coadministration of DEHP and DBP was able to increase the diameter of seminiferous cords and induce gonocyte multinucleation at doses that individually had no significant effects on these variables. However, in the phthalate mixture group, no significant changes were observed in anogenital distance and nipple retention, variables that are used to indicate possible anti-androgenic effects. Also, the adult endpoints investigated, that included reproductive organ weights and the number of spermatids per testis, were unaffected by any treatment regimen. Overall, coadministration of DEHP and DBP in utero significantly reduced testicular testosterone levels and resulted in misshapen seminiferous cords and gonocyte multinucleation in rat foetal testis. Our results also confirm that these foetal endpoints seem to be the most sensitive markers of prenatal phthalate exposure.

Morinda citrifolia Linn (Noni): in vivo and in vitro reproductive toxicology.

UNLABELLED: Morinda citrifolia Linn (syn. Noni) is a plant widely used as food and medicine worldwide but there are no toxicological tests about this plant focused on reproduction. AIM OF THE STUDY: To investigate possible endocrine activity and toxic effect on the reproductive system of Wistar rats by exposure of aqueous extract of the Morinda citrifolia. MATERIALS AND METHODS: Two experimental protocols in vivo were developed, (a) uterotrophic assay and (b) in utero and lactational assay, and one test in vitro to investigate the effect on the contractility of pregnant uteri isolated from rats (doses of the extract: 7.5, 75 and 750 mg/kg). RESULTS: The uterotrophic assay indicates presence of in vivo antiestrogenic activity of extract at doses of 7.5 and 750 mg/kg. The in utero and lactation exposure showed that the treatment with extract at the dose of 7.5mg/kg induced a reduction of 50% in parturition index and an increase of 74% in postimplantation losses index. The in vitro test showed that uteri from rats treated with 7.5mg/kg of the extract presented a 50% reduction on contraction induced by arachidonic acid. CONCLUSION: The exposure of aqueous extract of Morinda citrifolia in Wistar rats induced reproductive toxicity in nonlinear dose-response.

Reproductive effects of di(2-ethylhexyl)phthalate in immature male rats and its relation to cholesterol, testosterone, and thyroxin levels.

Phthalates are chemicals employed in several industrial products and there is a growing body of evidence demonstrating that they induce numerous adverse effects on the reproductive system. This study was carried out to assess possible alterations induced by the plasticizer di(2-ethylhexyl phthalate (DEHP) on cholesterol, testosterone, and thyroxine (total T4) levels, as well as to discuss the significance of these data in global changes observed in the reproductive tract of pubertal animals. Wistar rats aged 21 days received DEHP orally at 0, 250, 500, and 750 mg/kg/day for 30 days and were examined for different reproductive endpoints. At the end of the treatment, significant decreases in relative weight of testosterone-dependent organs, delayed preputial separation, and low serum testosterone were observed at the highest DEHP dose. The plot of the relationship between DEHP dose and serum cholesterol revealed a biphasic effect. The concentration of cholesterol in serum was significantly reduced at 250 mg/kg/day DEHP but returned to control values at 750 mg/kg/day. Cholesterol levels measured in testicular tissue increased with DEHP treatment. Serum T4 levels were not affected by DEHP at any dose, indicating the absence of a link between total thyroxin concentration and phthalate effects on cholesterol levels. Taken together these results indicate that effects observed in serum and testicular cholesterol levels may reflect distinct effects of DEHP on cholesterol synthesis and usage. These results confirm and extend previously reported findings showing that alterations in cholesterol balance may play a role in the suppression of steroidogenesis induced by DEHP in rats.

Vitamin C and resveratrol supplementation to rat dams treated with di(2-ethylhexyl)phthalate: impact on reproductive and oxidative stress end points in male offspring.

This study was carried out to assess the influence of di(2-ethylhexyl)phthalate (DEHP) alone or associated with antioxidants on the male reproductive system in newborn rats, emphasizing the implications of oxidative stress and hormonal balance during prenatal and early postnatal periods. Wistar females were exposed by oral route to DEHP alone or associated with antioxidants from gestational day 7 to lactational day 2 according to the following treatment regimens: (C) vehicle control (canola oil + 1% Tween-80); (V) vitamin C (200 mg/kg) + canola oil; (R) resveratrol (10 mg/kg) + canola oil; (D) DEHP (500 mg/kg) + 1% Tween-80; (DV) DEHP (500 mg/kg) + vitamin C (200 mg/kg); and (DR) DEHP (500 mg/kg) + resveratrol (10 mg/kg). Two male pups per litter were randomly selected and necropsied on postnatal day 2. The brain and liver were removed and weighed and anogenital distance (AGD) was measured. Additionally, the testes were removed for assessment of intratesticular testosterone levels and histopathology; the liver was used to measure biomarkers of oxidative stress. Vitamin C and resveratrol alone did not affect the reproductive end points and did not induce oxidative stress. Exposure of dams to DEHP alone and associated with antioxidants resulted in hepatomegaly in offspring and significantly increased the incidence of multinucleated gonocytes in seminiferous cords. Testosterone and AGD presented a trend to decrease in DEHP-exposed groups. Catalase activity increased only in groups exposed to DEHP associated with antioxidants, although GST (gluthatione-S-transferase) activity decreased in all DEHP-exposed groups. The levels of hydroperoxides increased only in group exposed to DEHP associated with vitamin C. These results indicate that the association of DEHP with antioxidants was unable to ameliorate DEHP-induced reproductive changes, and the coadministration of DEHP and these antioxidants might even contribute to an overall increase in oxidative stress.

Toxicity of artemisinin [Artemisia annua L.] in two different periods of pregnancy in Wistar rats.

Artemisinin compounds are important for treating multidrug-resistant malaria; however, the possible resorption and abnormalities observed in animal reproduction studies may contraindicate artemisinin use during the first trimester. To evaluate whether artemisinin interferes with developmental outcomes at different periods of pregnancy, Wistar rats were treated by gavage with increasing doses of 7, 35 and 70 mg/kg/day from gestational day [GD] 7 to 13 or 14 to 20. Viable embryos and post-implantation losses, and progestagens and testosterone levels, were monitored in the former treatment group and pregnancy and outcomes data, post-implantation losses and male and female developmental endpoints of the offspring were evaluated in the latter treatment group. Results indicate toxicity for both periods of treatment, with lower sensitivity at later stages of pregnancy. The results showed that dosing with 35 or 75 mg/kg of artemisinin caused high percentages of post-implantation losses that correlated with a trend to lower maternal progestagens and a significant maternal testosterone decrease. These findings demonstrate that oral administration of artemisinin can adversely effect post-implantation development and pregnancy in the rat.

Chlorpyrifos induces anxiety-like behavior in offspring rats exposed during pregnancy.

Chlorpyrifos is a pesticide, member of the organophosphate class, widely used in several countries to manage insect pests on many agricultural crops. Currently, chlorpyrifos health risks are being reevaluated due to possible adverse effects, especially on the central nervous system. The aim of this study was to investigate the possible action of this pesticide on the behaviors related to anxiety and depression of offspring rats exposed during pregnancy. Wistar rats were treated orally with chlorpyrifos (0.01, 0.1, 1 and 10mg/kg/day) on gestational days 14-20. Male offspring behavior was evaluated on post-natal days 21 and 70 by the elevated plus-maze test, open field test and forced swimming test. The results demonstrated that exposure to 0.1, 1 or 10mg/kg/day of chlorpyrifos could induce anxiogenic-like, but not depressive-like behavior at post-natal day 21, without causing fetal toxicity. This effect was reversed on post-natal day 70.

Reproductive evaluation of two pesticides combined (deltamethrin and endosulfan) in female rats.

Data from in vitro studies suggest that the pesticides deltamethrin (D) and endosulfan (E) exert estrogen-like effects. There is concern that interaction between weakly estrogenic compounds can increase their estrogenic potency. The aim of the present study was to determine estrogenic activity in an animal model and the possible female reproductive adverse effects of these pesticides combined. Wistar rats received daily (po), from day 6 of pregnancy to day 21 of lactation, deltamethrin and endosulfan concomitantly: D: 2.0 mg/kg+E: 1.5 mg/kg, or D: 3.0 mg/kg+E: 2.0 mg/kg, or D: 4.0 mg/kg+E: 3.0mg/kg. Some offspring also were exposed directly after weaning. Maternal and reproductive outcome data were assessed. An uterotrophic assay to screen in vivo estrogenic activity of D+E was also performed. A group of female offspring was analyzed for vaginal opening (VO), first estrus, estrous cycle regularity, and weights of the uterus and ovaries. No signs of maternal toxicity were detected. Results from the uterotrophic assay indicate absence of in vivo estrogenic activity of D+E. No significant variations in reproductive endpoints of females were observed. These results suggest that administration of D+E does not pose a reproductive hazard to female rats exposed during critical periods of development, indicating that the combination does not exert estrogen-like effects in vivo or is not delivered to target organs.

Reproductive evaluation of aqueous crude extract of Achillea millefolium L. (Asteraceae) in Wistar rats.

The present study was conducted to evaluate the toxicity of the exposure to the aqueous extract from leaves (AE) of Achillea millefolium L. on reproductive endpoints in Wistar rats. Adult male rats were treated daily with yarrow extract (0.3, 0.6 and 1.2 g/kg/day) during 90 days by oral gavage. Endpoints including reproductive organ weights, sperm and spermatid numbers as well as sperm morphology were evaluated. No clinical signs of toxicity were detected over the treatment period, and body weight gain was similar in all groups. A significant increase in the percentage of abnormal sperm in the group treated with the highest dose of yarrow extract was detected with no other important changes in the other reproductive endpoints studied in the male rats. Furthermore, a possible estrogenic/antiestrogenic activity of the yarrow extract screened after a 3-day treatment of immature female rats which did not show any uterotrophic effects.

Pre and postnatal exposure to endosulfan in Wistar rats.

The possible reproductive adverse effects of the pesticide endosulfan on male offspring rats exposed in utero and during lactation were investigated. Dams were treated orally with 0, 0.5 or 1.5 mg of endosulfan/kg 21 days prior to mating, during the mating, pregnancy and lactation. Maternal and reproductive outcome data and male sexual development landmarks (testis descent and preputial separation) were assessed. Reproductive endpoints of the male offspring were examined at adulthood: sex organ weights, daily sperm production, spermatid number, sperm transit, sperm morphology and testosterone level. No signs of maternal toxicity were detected at the dose levels tested. Sexual development landmarks were also unaffected. Moreover, with the exception of a significant increase in the relative epididymis weight seen in the group treated with the lowest dose, we have not found any statistically significant adverse effect in the reproductive endpoints investigated at adulthood. The results of the present study indicate that pre and postnatal exposure to low doses of endosulfan (0.5 and 1.5 mg/kg) do not induce significant adverse effects in the reproductive system of male offspring Wistar rats at adulthood.

In utero and lactational exposure to fluoxetine in Wistar rats: pregnancy outcomes and sexual development.

This study evaluated the reproductive effects of fluoxetine exposure in utero and during lactation on pregnancy outcomes and the sexual development of offspring. Pregnant Wistar rats were treated daily with fluoxetine (0.4, 1.7 and 17 mg/kg/day) or distilled water by gavage from gestation day (GD) 7 to lactation day (LD) 21. A significant reduction in maternal body weight was observed during pregnancy and lactation in dams exposed to 17 mg/kg fluoxetine. Hormone analysis revealed an increase in progestagen and glucocorticoid metabolites on GD 15 and oestrogen and progestagen metabolites on LD 7 in dams treated with 17 mg/kg fluoxetine. Oestrogen metabolites also were increased on LD 7 in dams treated with 0.4 mg/kg fluoxetine. Besides that, an increase in the weight of the adrenal glands and a reduction in uterine weight in dams exposed to highest dose of fluoxetine were observed. Finally, pup birthweight and the viability and weaning indices also were reduced in animals exposed to 17 mg/kg fluoxetine. Overall, maternal hormonal changes were only observed at the highest dose tested, which also induced maternal and foetal toxicity. No significant changes were seen in dams or offspring exposed to therapeutic-like doses.

In vivo and in vitro estrogenic activity of the antidepressant fluoxetine.

Recent years have seen an increase in the use of antidepressant drugs, especially fluoxetine (FLX), in sensitive populations, such as pregnant and lactating women. Although some evidence suggests a possible endocrine action of FLX, no specific studies have been performed to investigate this hypothesis. In the present study, we investigated the possible (anti)androgenic and (anti)estrogenic actions of FLX using Hershberger, uterotrophic (0.4, 1.7, and 17mg/kg), and reporter gene (7.6-129µM) assays. In the Hershberger assay, no differences were observed in androgen-dependent organ weights. However, the uterotrophic and gene reporter assays indicated a possible estrogenic action of FLX. Uterine weight increased in the 1.7 and 17mg/kg/day groups in the 3-day uterotrophic assay in immature rats. Additionally, noncytotoxic concentrations of FLX induced estrogenic responses and increased the estrogenic response of estradiol in MCF-7 breast cancer cells transfected with luciferase.

Tipagem molecular e resistência aos antimicrobianos em isolados de Escherichia coli de frangos de corte e de tratadores na região metropolitana de Curitiba, Paraná / Molecular typing and antimicrobial resistance in isolates of Escherichia coli from poultry and farmers in the metropolitan region of Curitiba, Paraná

Este estudo verificou o perfil de resistência aos antimicrobianos entre isolados de Escherichia coli de frangos de corte de criação intensiva e de subsistência e dos respectivos tratadores e a similaridade genotípica entre isolados de E.coli de frangos de corte de criação intensiva e isolados de E. coli de tratadores de frangos de criação intensiva pela técnica de Eletroforese em Gel de Campo Pulsado (PFGE). 60 amostras de fezes de frangos de criação intensiva, 60 de frangos de corte de criação de subsistência (caipira) e 20 amostras dos tratadores de frangos de criação intensiva e 20 de tratadores de frangos de criação de subsistência. E. coli foram isoladas, identificadas e submetidas ao teste de suscetibilidade a 12 antimicrobianos. Pela PFGE foram analisados 24 isolados de E. coli de frangos de corte de criação intensiva e oito de tratadores. Em isolados E. coli de frangos de criação intensiva a resistência para a ampicilina foi de 100%, cefotaxima 43%, ceftriaxona 48%, ácido nalidíxico 62%, enrofloxacina 23%, ciprofloxacina 23%, tetraciclina 83% e 45% para trimetoprim-sulfametoxazol. Nos isolados de frangos de criação de subsistência foi de 20%, 0%, 0%, 5%, 2%, 4%, 33% e 8%, respectivamente...

This study examined the profile of antimicrobial resistance among isolates of Escherichia coli from poultry intensive farming and free-range systems and their farmers. For technique of Gel Electrophoresis Pulsed Field (PFGE) examined the similarity between isolates from poultry intensive farming and their farmers. From 60 samples of poultry feces from intensive farming systems, 60 of free-range extensive systems and 20 of farmers of each segment, the E. coli was isolated and submitted to the test of susceptability to 12 antimicrobials. 24 isolates of E. coli of poultry from intensive farming systems and eight E. coli isolates from farmers poultry intensive farming were analyzed via technique of PFGE. In intensive farming systems poultry, 100% resistence to ampicillin was verified, 43% to cefotaxime, 48% to ceftriaxone, 62% to nalidixic acid, 23% to enrofloxacin, 23% to ciprofloxacin, 83% to tetracycline and 45% to trimetroprim-sulfametoxazol. In the strains of free-range extensive systems, resistance was 20%, 0%, 0%, 5%, 2%, 4%, 33% and 8%, respectively...

Effects of Tribulus terrestris on endocrine sensitive organs in male and female Wistar rats.

AIM OF THE STUDY: Investigate the possible effects of Tribulus terrestris (TT) on endocrine sensitive organs in intact and castrated male rats as well as in a post-menopausal rat model using ovariectomized females. MATERIALS AND METHODS: Three different dose levels of TT (11, 42 and 110 mg/kg/day) were administered to castrated males for 7 days and to intact males and castrated females for 28 days. In addition to TT treatment, all experiments also included a group of rats treated with dehydroepiandrosterone (DHEA). In experiments using castrated males and females we also used testosterone and 17 alpha-ethynylestradiol, respectively, as positive controls for androgenicity and estrogenicity. RESULTS: Neither DHEA nor TT was able to stimulate androgen sensitive tissues like the prostate and seminal vesicle in both intact and castrated male rats. In addition, administration of TT to intact male rats for 28 days did not change serum testosterone levels as well as did not produce any quantitative change in the fecal excretion of androgenic metabolites. However, a slight increase in the number of homogenization-resistant spermatids was observed in rats treated with 11 mg/kg/day of TT extract. In ovariectomized females, TT did not produce any stimulatory effects in uterine and vaginal epithelia. CONCLUSIONS: Tribulus terrestris was not able to stimulate endocrine sensitive tissues such as the prostate, seminal vesicle, uterus and vagina in Wistar rats, indicating lack of androgenic and estrogenic activity in vivo. We also showed a positive effect of TT administration on rat sperm production, associated with unchanged levels of circulating androgens.

Pre- and postnatal toxicity of the commercial glyphosate formulation in Wistar rats.

Glyphosate is the active ingredient and polyoxyethyleneamine is the surfactant present in the herbicide Roundup formulation commercialized in Brazil. The aim of this study was to assess the reproductive effects of glyphosate-Roundup on male and female offspring of Wistar rats exposed during pregnancy and lactation. Dams were treated orally with water or 50, 150 or 450 mg/kg glyphosate during pregnancy (21-23 days) and lactation (21 days). These doses do not correspond to human exposure levels. The results showed that glyphosate-Roundup did not induce maternal toxicity but induced adverse reproductive effects on male offspring rats: a decrease in sperm number per epididymis tail and in daily sperm production during adulthood, an increase in the percentage of abnormal sperms and a dose-related decrease in the serum testosterone level at puberty, and signs of individual spermatid degeneration during both periods. There was only a vaginal canal-opening delay in the exposed female offspring. These findings suggest that in utero and lactational exposure to glyphosate-Roundup may induce significant adverse effects on the reproductive system of male Wistar rats at puberty and during adulthood.

Reproductive effects of deltamethrin on male offspring of rats exposed during pregnancy and lactation.

The effects of low doses of deltamethrin administered to female rats on the reproductive system of male offspring were examined. The dams (n=10-12/group) were treated daily by oral gavage with 0, 1.0, 2.0, and 4.0 mg deltamethrin/kg from day 1 of pregnancy to day 21 of lactation. Maternal and reproductive outcome data and male sexual development landmarks were assessed. Fertility, sexual behavior, and a large number of reproductive endpoints, such as organ weights, sperm evaluations, testosterone concentration, and testicular histology were examined on adult male offsprings. No signs of maternal toxicity were detected at the dose levels tested. Significantly adverse effects were only seen on testicular and epididymal absolute weights and the diameter of seminiferous tubules in the group treated with the highest dose of deltamethrin (4.0 mg/kg). The results indicate that in utero and lactational exposure to deltamethrin may induce subtle changes in reproductive behavior and physiology of male offspring rats at dose levels that do not cause maternal toxicity.