Toxic effects of Aroclor 1254 on rat liver and modifying roles of selenium

Polychlorinated biphenyls (PCBs) were used in different industrial areas and banned due to their high toxicity. Aroclor 1254 (A1254), commercial PCB congener, accumulates in environment leading to high human exposure. A1254 may cause hepatotoxicity, metabolic and endocrine disorders. In our study, 3-week-old male rats were separated into 6 groups: C (0.15 mg/kg Se in diet); SeS (1 mg/kg Se in diet); SeD (0.05 mg/kg Se in diet); A1254 receiving groups (A; ASeS; ASeD) were given 10 mg/kg/day A1254 orally for last 15 days of feeding period with control, SeD or SeS diet, respectively, for 5 weeks. Histopathology, oxidant/antioxidant balance, apoptosis and cell cycle proteins (p53, p21) in liver were evaluated. Our results suggest that A1254 leads to changes in histology, oxidative stress and apoptosis. Selenium deficiency augments oxidative stress and apoptosis while selenium supplementation is partially protective. More mechanistic in vivo experiments are necessary for evaluation of hepatotoxicity of PCBs.

The evaluation of possible role of endocrine disruptors in central and peripheral precocious puberty

Exposure to environmental chemicals can affect genetic and epigenetic molecular pathways and may cause altered growth and development. Among those exposures, endocrine-disrupting chemicals (EDCs) are of particular concern as humans are abundantly exposed to these chemicals by various means in every period of life. Several well-known environmental chemicals, including phthalates and bisphenol A (BPA), are classified as EDCs. These EDCs are suggested to play roles in early onset of puberty in girls. The aim of this study is to determine plasma phthalate (di(2-ethylhexyl)phthalate [DEHP] and its main metabolite mono(2-ethylhexyl)phthalate [MEHP]) and urinary BPA levels in girls with idiopathic central precocious puberty (CPP) and peripheral precocious puberty (PPP). This study was performed on newly diagnosed idiopathic central precocious puberty (CPP) patients (n = 42) and peripheral precocious puberty (PPP) (n = 42) patients, who were admitted to Keçiören Training and Research Hospital, Clinic of Pediatric Endocrinology between August 2012 and -July 2013. Nonobese healthy girls (n = 50) were used as the control group. Urinary BPA levels were not statistically different in control, PPP and CPP groups (medians 10.91, 10.63 and 10.15 μg/g creatinine, respectively; p > 0.05). Plasma DEHP levels were significantly higher in PPP group when compared to control. Plasma MEHP levels were not significantly different in control and PPP groups (p > 0.05). However, in CPP group, both plasma DEHP and MEHP levels were significantly higher than control and PPP groups. This study showed that phthalates might play a role in the occurence of CPP in girls.