Abstract:

Di-(2-ethylhexyl)-phthalate (DEHP) is used in polyethylene terephthalate plastics and bisphenol-A (BPA) is used to make polycarbonate plastics. The health-concerning effects of DEHP and BPA indicate their potential toxic effects. The Wnt/β-catenin signaling pathway is necessary for embryonic development. The c-MYC proto-oncogene (MYC) has been identified as a Wnt/β-catenin target gene, and MYC is a transcription factor that regulates the expression of many gene products related to cell proliferation, growth, differentiation, and apoptosis. Activation and overexpression of the MYC gene has been reported in many human cancers and during tumorigenesis. The aim of this study was to investigate the relationship between oxidant-antioxidant balance and c-myc in BPA- and DEHP-exposed zebrafish embryos. The real-time-polymerase chain reaction was used to determine c-myc expression. Lipid peroxidation (LPO), nitric oxide (NO) levels, and superoxide dismutase (SOD) and glutathione-S-transferase (GST) activities were determined in homogenates prepared from pooled embryo samples. Increased expression of c-myc and decreased GST activity were observed in the BPA and DEHP groups. NO levels increased and SOD activity decreased in the BPA group, whereas LPO increased in the DEHP group. Disruption of oxidant-antioxidant balance in DEHP- and BPA-exposed zebrafish embryos was associated with increased c-myc expression and may be an important mechanism for the toxic effects of these chemicals. 

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