Urinary bisphenol A levels in Turkish girls with premature thelarche.

There is a growing concern over the timing of pubertal breast development and its possible association with exposure to endocrine disrupting chemicals (EDCs), such as bisphenol A (BPA). BPA is abundantly used to harden plastics. The aim of this study was to investigate the relation between premature thelarche (PT) and BPA by comparing the urinary BPA levels of PT girls with those of healthy subjects. Twenty-five newly diagnosed nonobese PT subjects (aged 4-8 years) who were admitted to the Pediatric Endocrinology Department at Akdeniz University were recruited. The control group composed of 25 age-matched girls without PT and other endocrine disorders. Urinary BPA levels were measured by high pressure liquid chromatography. The median urinary concentrations of BPA were found to be significantly higher in the PT group compared to the healthy control group (3.2 vs. 1.62 µg/g creatinine, p < 0.05). We observed a weak positive correlation between uterus volume and urinary BPA levels. There was a weak correlation between estradiol and urinary BPA levels ( r = 0.166; p = 0.37); and luteinizing hormone and urinary BPA levels ( r = 0.291; p = 0.08) of PT girls. Our results suggest that exposure to BPA might be one of the underlying factors of early breast development in prepubertal girls and EDCs may be considered as one of the etiological factors in the development of PT.

Urinary zearalenone levels in girls with premature thelarche and idiopathic central precocious puberty.

AIM: Recently, it was reported that the development of breast tissue and secondary sex characteristics in girls occurred at much younger age and the incidences of premature thelarce (PT) and central idiopathic precocious puberty (ICPP) are increasing. In this context, we wanted to evaluate the mycoestrogen exposure as triggering factor for premature sexual development. METHODS: The girls living in Mediterranean region of Turkey were divided in to three groups: control (N.=25; mean age: 6.45 ± 1), PT (N.=28; mean age: 6.86 ± 0.95) and ICPP (N.=25; mean age: 6.97 ± 0.87). Urinary ZEN levels were measured by using ELISA technique and were normalized by urinary creatinine levels. Body Mass Index (BMI) was evaluated and sex hormone levels were also measured. RESULTS: We found that urinary ZEN was detectable in ~81% of all samples and observed an increase of ~2-fold in PT and a significant increase ~2.8-fold in ICPP group vs. control. We did not find any significant correlations between urinary ZEN levels and BMI and sex hormones in any of the groups. CONCLUSION: To our knowledge, this is the first study evaluating urinary ZEN levels in PT and ICPP Turkish patients. We can postulate that ZEN exposure can contribute to the etiology of PT and PP; however further studies on large number of subjects are needed to confirm the present data.

Induction of ROS, p53, p21 in DEHP- and MEHP-exposed LNCaP cells-protection by selenium compounds.

This study was designed to investigate the hypothesis that the toxic effects of di(2-ethylhexyl)phthalate (DEHP), the most abundantly used plasticizer and ubiquitous environmental contaminant that cause alterations in endocrine and spermatogenic functions in animals is mediated through the induction of reactive oxygen species (ROS) and activation of nuclear p53 and p21 proteins in LNCaP human prostate adenocarcinoma cell line. Protective effects of two selenocompounds, sodium selenite (SS) and selenomethionine (SM) were also examined. It was demonstrated that 24 h exposure of the cells to 3 mM DEHP or its main metabolite, mono(2-ethylhexyl)phthalate (MEHP, 3 µM) caused strongly amplified production of ROS. Both SS (30 nM) and SM (10 µM) supplementations reduced ROS production, and p53 and p21 activation that induced significantly only by MEHP-exposure. The overall results of this study indicated that the induction of oxidative stress is one of the important mechanisms underlying the toxicity of DEHP and this is mainly through the effects of the metabolite, MEHP. Generated data also emphasized the critical role of Se in modulation of intracellular redox status, implicating the importance of the appropriate Se status in cellular response against testicular toxicity of phthalates.