title: Impaired antioxidant gene expression by pesticide residues and its relation with other cellular biomarkers in Nile Tilapia (Oreochromis niloticus) from Lake Burullus.
abstract: Organochlorines and Organophosphorus are the most commonly used pesticides. These pesticides constitute a considerable contaminating threat due to their excessive agricultural usage which in turn contaminates the aquatic system through agricultural drainage. The aim of this study was to evaluate water and tissue residues of both pesticides in O. niloticus obtained from three different sections in Lake Burullus, Egypt. Assessment of relative change in mRNA levels of GST and Vtg (oxidative stress indicator) was done and its relation with other cellular biomarkers including apoptosis, which is assessed by Cellular apoptosis susceptibility transcript level (CAS), comet assay and micronucleus assays (genotoxicity indicator). Pesticide residue levels in water are fluctuating. In fish tissues, most residues were higher than those found in water and were associated with down regulation of hepatic GST gene and Vtg expression. CAS gene involved in apoptosis, its transcript is down regulated in middle and western sections of the lake with higher pesticide residues. Different degrees of DNA damages in O. niloticus' liver cells were demonstrated by comet assay. Significant increase in the micronucleated cells in the three sections of the lake was observed; the western section fish showed the highest number. Persistent exposures of fish to pesticide caused impairment of antioxidant gene expression. This negatively affects apoptosis associated with damaging DNA and chromosome fragments.
authors.affiliation: Animal Husbandry and Animal Wealth Department, Faculty of Veterinary Medicine, Alexandria University, Egypt. Electronic address: abeer.elnahas@alexu.edu.eg.
authors.forename: Abeer F
authors.initials: AF
authors.lastname: El Nahas
authors.affiliation: Department of Chemistry and Toxicity of Pesticides, Faculty of Agriculture, Kafrelsheikh University, Egypt.
authors.forename: Mohamed A S
authors.initials: MA
authors.lastname: Abdel-Razek
authors.affiliation: Biotechnology department, Animal Health Research Institute, Dokki, Egypt.
authors.forename: Nashwa M
authors.initials: NM
authors.lastname: Helmy
authors.affiliation: Department of Physiology, Faculty of Veterinary Medicine, Kafrelsheikh University, Egypt.
authors.forename: Shawky
authors.initials: S
authors.lastname: Mahmoud
authors.affiliation: Biotechnology department, Animal Health Research Institute, Kafrelsheikh, Egypt.
authors.forename: Haneen A
authors.initials: HA
authors.lastname: Ghazy
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D023681:Cichlids / Q000378:metabolism*; D020552:Comet Assay; D004534:Egypt; D015870:Gene Expression / Q000187:drug effects; D006843:Hydrocarbons, Chlorinated / Q000378:metabolism / Q000633:toxicity; D060106:Lakes / Q000032:analysis; D018384:Oxidative Stress / Q000502:physiology; D010573:Pesticide Residues / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D006843:Hydrocarbons, Chlorinated; D010573:Pesticide Residues; D014874:Water Pollutants, Chemical
keywords: Apoptosis; Comet assay; Micronucleus; Oreochromis niloticus; Oxidative stress; Pesticide residues