Effects of Talinum paniculatum (Jacq.) Gaertn. leaf extract on general toxicity and pubertal development of rats.

Talinum paniculatum (Jacq.) Gaertn. (Talinaceae), popularly known as "major gomes," is a Brazilian Cerrado plant used in traditional medicine and as a food source. Recent studies have demonstrated its diuretic effects. However, no studies have been performed on its effects on the reproductive system. Therefore, we aimed to investigate the effects of the ethanol-soluble fraction of T. paniculatum leaves (ESTP) on general toxicity and on the pubertal development of male and female Wistar rats. For this purpose, the uterotrophic and the pubertal assays were performed. In the uterotrophic test, female immature rats were treated for three consecutive days with 30, 100, or 300 mg/kg of ESTP. Uterus without luminal fluid was weighed and the relative weight calculated. For the pubertal assay, male and female immature rats were submitted to 30-day treatment with 30 or 300 mg/kg of ESTP. Clinical signs of toxicity, biochemical, and histopathological parameters were evaluated. ESTP treatment did not promote estrogenic effects in female rats. In the pubertal test, no daily signs of toxicity or weight loss were observed. Moreover, ESTP did not affect the onset of vaginal opening and preputial separation and did not cause significant changes in biochemical parameters as well as in organ weight and histopathological analyses of animals.

Experimental cryptorchidism enhances testicular susceptibility to dibutyl phthalate or acrylamide in Sprague-Dawley rats.

Cryptorchidism (CPT), the most common male congenital abnormality, is variably associated with other male reproductive tract problems. We evaluated if cryptorchid rats develop enhanced testicular susceptibility to dibutyl phthalate (DBP) or acrylamide (AA) after extended exposure. Three studies with rats were performed: (1) in utero and postnatal exposure to DBP or AA; (2) establishment of CPT and orchiopexy; and (3) in utero and postnatal exposures to DBP or AA associated with CPT/orchiopexy. Seminiferous tubules were histologically scored according to the severity of lesions: (1) Rats exposed to DBP (score 1.5) or AA (score 1.1) presented mostly preserved spermatogenesis. Some seminiferous tubules showed vacuolated germinative epithelium, germ cell apoptosis, and a Sertoli cell-only (SCO) pattern. (2) CPT (score 3.3) resulted in decreased absolute testes weights, degenerated and SCO tubules, and spermatogenesis arrest that were reversed by orchiopexy (score 1.1). (3) Exposure to DBP or AA with CPT/orchiopexy led to atrophic testes, spermatogenesis arrest, germ cell exfoliation/multinucleation, and SCO tubules (both chemicals score 2.5). Exposure to chemicals such as DBP or AA prevented the recovery of cryptorchid testes by orchiopexy. The possible role of environmental contaminants should be considered when looking for factors that modulate human testicular disorders associated with CPT.

Timing of prenatal phthalate exposure in relation to genital endpoints in male newborns.

Prior studies report that penile size and male anogenital distance (AGD), sensitive markers of androgen action in utero, may be shortened by prenatal exposure to certain phthalates, including diethylhexyl phthalate (DEHP), but no human study has investigated the importance of exposure timing in these associations. The aim of this study was to examine the significance of exposure timing on the action of prenatal phthalates in particular DEHP, on male infant penile size and AGD. In The Infant Development and the Environment Study (TIDES) we measured penile width (PW) as well as anoscrotal distance (AGDAS ) and anopenile distance (AGPAP ) in newborn males. We modeled these endpoints in relation to phthalate metabolite concentrations in maternal urine samples collected in each trimester (T1, T2, and T3) in a subset of TIDES mothers (N = 168). PW was inversely associated with T2 oxidized DEHP metabolites, mono-2-ethyl-5-oxohexyl (MEOHP, ß=-0.48; 95% confidence interval, -0.93, -0.02), MEHHP (-0.48; -0.92, -0.05), mono-2-ethyl-5-carboxypentyl (MECPP, -0.51; -1.01, -0.004), although no appreciable associations were seen between PW and T1 and T3 DEHP metabolite concentrations in this subset. Concentrations of DEHP metabolites in T1 urine samples were inversely related to male AGD. For example, in T1 samples in this subset of women mono-2-ethyl-5-hydroxyhexyl (MEHHP) was inversely associated with male AGDAP (ß = -1.73; 95% confidence interval, -3.45, 0.0004). However, no appreciable associations were seen between AGD measures and any DEHP metabolite in T2 and T3 samples. These data suggest that DEHP exposure is inversely associated with AGD and PW, with PW primarily associated with T2 exposure and AGD associations seen only for T1 exposure, but no associations were found between T3 DEHP metabolites and any of these genital endpoints. These findings are consistent with data on critical windows in rodent studies, supporting the biological plausibility of these associations in humans.

The plasticizer dibutyl phthalate (DBP) potentiates chemical allergen-induced THP-1 activation.

Recent studies suggest that phthalates may have a role in the development of allergic diseases, probably due to an adjuvant effect. The present study aimed to investigate the possible adjuvant effect of dibutyl phthalate (DBP) in two in vitro models of contact-allergen induced cell activation, namely the NCTC 2544 IL-18 assay and the THP-1 activation assay. Results show no adjuvant effect in the human keratinocyte cell line NCTC 2544, indicated by lack of increase in interleukin 18 (IL-18) production after exposure to p-Phenylenediamine (PPD) in association with DBP. On the contrary, increased upregulation of CD86 and interleukin 8 (IL-8) production were observed in THP-1 cells exposed to combinations of citral (Cit) or imidazolidinyl urea (IMZ) with DBP, indicative of an adjuvant effect. Additionally, higher production of reactive oxygen species (ROS) in THP-1 cells treated with DBP associated to Cit supports that oxidative stress could be part of the molecular mechanism of the observed adjuvant effect. In conclusion, we demonstrate that DBP presents in vitro an adjuvant effect for immune stimulation in dendritic cells but not in keratinocytes. Future studies are necessary to elucidate the precise mechanism underlying the adjuvant effect of DBP in vitro and in vivo.

Influence of oily vehicles on fetal testis and lipid profile of rats exposed to di-butyl phthalate.

It has been hypothesized that oils containing high levels of omega-3 polyunsaturated fatty acids, such as canola and fish oil, could counteract some of the adverse effects induced by phthalates. In the present study, the influence of different oily vehicles on di-butyl phthalate (DBP)-induced testicular toxicity and lipid profile was investigated. Pregnant Wistar rats were treated by oral gavage from gestation days 13 to 20 with DBP (500 mg/kg/day) diluted in three different vehicles: corn, canola or fish oil. Male fetuses were analyzed on gestation day 20. DBP exposure lowered intratesticular testosterone levels and anogenital distance, regardless of the vehicle used. The percentage of seminiferous cords containing multinucleated gonocytes and cord diameter was increased in DBP-exposed groups, compared with vehicle controls, with no difference between the three DBP-exposed groups. Clustering of Leydig cells was seen in all DBP groups. Lipid profile indicated that administration of canola and fish oil can increase the content of omega-3 fatty acids in rat testis. However, content of omega-3 was diminished in DBP-treated groups. Overall, our results indicate that different oily vehicles did not alter fetal rat testicular toxicity induced by a high DBP dose.

Testicular testosterone: estradiol ratio in domestic cats and its relationship to spermatogenesis and epididymal sperm morphology.

The phenomenon of teratozoospermia in felids is not fully understood. In this study, we investigated the testicular androgen:estrogen balance in domestic cats and correlated these data with epididymal sperm morphology and the degree of spermatogenic activity. During spring and summer, testes and blood samples were obtained from 37 mixed-breed domestic cats (12 to 48 mo). The epididymal sperm were harvested and evaluated for sperm counts, motility, and morphology. Distal cytoplasmic droplets were not considered a defect, and samples were considered normozoospermic if they contained more than 60% normal sperm (N = 25) or teratozoospermic if they contained less than 45% normal sperm (N = 12). The testicular and serum concentrations of testosterone (T) and 17ß-estradiol (E2) were determined with an enzyme immunoassay. The gonadosomatic index and epididymal sperm numbers and motility did not differ between groups. The percentage of normal sperm was higher in normozoospermic (74.3 ± 2.0, mean ± SEM) than in teratozoospermic samples (43.1 ± 1.4). The most prevalent sperm defects in the teratozoospermic group were abnormal acrosomes (9.7 ± 2.0) and bent midpieces (12.2 ± 2.0) or tails (24.0 ± 2.7) with cytoplasmic droplets. Histomorphometric data were similar between groups, although there was a lower Leydig cell nuclear volume in teratozoospermic samples. Normozoospermic samples contained a higher percentage of haploid cells and had a higher index of total spermatogenic transformation than teratozoospermic samples. Serum concentrations of T (0.5 ± 0.1 vs. 0.8 ± 0.4 ng/mL) and E2 (9.5 ± 1.2 vs. 11.4 ± 2.3 pg/mL) and testicular T concentrations (471.6 ± 65.3 vs. 313.4 ± 57.6 ng/g) were similar between groups. However, compared with normozoospermic samples, teratozoospermic samples had higher testicular E2 concentrations (8.5 ± 3.6 vs. 5.4 ± 0.5 ng/g) and a lower T:E2 ratio (31.8 ± 4.1 vs. 87.2 ± 11.6). There were significant correlations between testicular E2 values and percentages of normal sperm (r = -0.55) as well as those with primary sperm defects (r = 0.58) or abnormal acrosomes (r = 0.64). The T:E2 ratio was also correlated with meiotic index (r = 0.45) and percentage of normal sperm (r = 0.58). In conclusion, a high testicular E2 concentration and a reduced T:E2 ratio were significantly associated with higher ratios of abnormal sperm types, suggesting that the balance between androgens and estrogens is an important endocrine component in the genesis of teratozoospermia in felids.