Impact of DBP on histology and expression of HSP 70 in gill and liver tissue of Cyprinus carpio.

Di-n-butyl phthalate (DBP) widely used plasticizer in the plastic industry, affects regulation of the endocrine system and causes toxicity in animals. In the present study, the aim was to study the toxic effects/damages of DBP exposure using Hsp70 levels and histopathological changes in Carp liver and gill. Hsp70 expression levels were assessed as specific biomarker of in vivo ecotoxicological stress. Carp (Cyprinus carpio) were exposed to sub-lethal concentration of DBP (di-n-butyl phthalate, 1 mg/L) for 4, 24 and 96 h. Gill and liver tissues were evaluated histopathologically and RNA quantifications for Hsp70 expression levels were carried out using a two-step real-time RT-PCR. In liver, a rapid but non-significant increase in mRNA levels in the first 4 h was observed. mRNA levels significantly increased up to 2-3 fold after 24 and 96 h (p < 0.05). However, irregular mRNA level changes were also recorded: Gill specific and time-dependent regulation of Hsp70 expression were 4-5 fold inhibition after 4 and 24 h (p < 0.05), then increased up to 4 fold after 96 h (p < 0.05). Histopathological findings support altered transcription results as: Epithelial lifting, hyperplasia, fusion of secondary lamellae, telangiectasis, passive hyperemia and hydropic degeneration. Significant alterations of Hsp70 levels were likely due to a tissue specific response against chemical stress, cellular damage and lesions due to DBP. Carp was found to be a suitable experimental model for toxicology, and Hsp70 mRNA levels are reliable, specific biomarkers.

Toxicity and molecular effects of di-n-butyl phthalate (DBP) on CYP1A, SOD, and GPx in Cyprinus carpio (common carp).

Di-n-butyl phthalate (DBP), a widely used plasticizer in the plastic industry, affects regulation of the endocrine system and causes toxicity in animals. In the present study, we evaluated a series of ecotoxicological stress biomarkers in the common carp (Cyprinus carpio) as an experimental model to test for alterations in gene expression at a sublethal concentration of 1 mg/L DBP for 4, 24, and 96 h. In gills, an immediate increase in CYP1A messenger RNA (mRNA) levels was observed within the first 4 h and persisted for 96 h. Protein levels were nearly consistent with mRNA levels. However, a time-dependent inhibition was observed in CYP1A levels in the liver within 96 h. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) levels increased gradually in liver with exposure time to a maximum level of 11-fold. Varied responses of different tissues were likely due to xenobiotic metabolism of DBP. In conclusion, evaluating the tissue-specific alterations of CYP1A, SOD, and GPx levels can be used as specific and effective biomarkers for ecotoxicological monitoring of DBP pollution. We strongly recommend using molecular tools to ecotoxicologists for aquatic monitoring of newly emerging pollutants.

Investigation of DNA damage by the alkaline comet assay in 131I-treated thyroid cancer patients.

OBJECTIVE: To assess the possible applicability of comet assay in the evaluation of DNA damage caused by ionizing radiation. The alkaline comet assay or single-cell gel electrophoresis has been used as a standard method for measuring and analyzing DNA damage. STUDY DESIGN: Peripheral blood samples were collected from papillary thyroid cancer patients who received 131I by oral administration. Blood samples were taken just before the treatment, on the first day of treatment, and 1 week posttreatment. To determine the radiation-induced DNA damage, alkaline comet assay was performed. RESULTS: It was found that significantly high levels of DNA damage occurred in first day samples when compared to control samples according to tail moment measurements. Also, a decrease in the level of damage was observed in the 1-week samples. CONCLUSION: Our observations and data confirmed that treatment with 131I for papilloma thyroid cancer can cause DNA damage in circulating lymphocytes, and the comet assay seemed suitable to assess the effect of radioactive iodine for the patients.