1.In vitro CYP1A activity in the zebrafish: temporal but low metabolite levels during organogenesis and lack of gender differences in the adult stage.
Saad M1, Verbueken E1, Pype C1, Casteleyn C1, Van Ginneken C1, Maes L2, Cos P2, Van Cruchten S3. Reprod Toxicol. 2016 Apr 1. pii: S0890-6238(16)30050-8. doi: 10.1016/j.reprotox.2016.03.049. [Epub ahead of print]
The zebrafish (Danio rerio) is increasingly used as a screening model for acute, chronic and developmental toxicity. More specifically, the embryo is currently investigated as a replacement of in vivo developmental toxicity studies, although its biotransformation capacity remains a point of debate. As the cytochrome P450 1 (CYP1) family plays an important role in the biotransformation of several pollutants and drugs, a quantitative in vitro protocol was refined to assess gender- and age-related CYP1A activity in the zebrafish using the ethoxyresorufin-o-deethylase (EROD) assay. Microsomal protein fractions were prepared from livers of adult males and females, ovaries and whole embryo homogenates of different developmental stages. A large biological variation but no gender-related difference in CYP1A activity was observed in adult zebrafish. Embryos showed distinct temporal but low CYP1A activity during organogenesis. These in vitro data raise questions on the bioactivation capacity of zebrafish embryos in developmental toxicity studies.
2.Thesis Abstract Study of biochemical changes in blood and various organs of Phrynops geoffroanus (Schweigger, 1812) (Testudines: Chelidae) collected in contaminated environment or exposed to benzo[a]pyrene.
Silva MI1, Silva TL1, Almeida EA1. Genet Mol Res. 2016 Feb 19;15(1). doi: 10.4238/gmr.15018568.
The aquatic organisms are often exposed to a wide variety of chemicals, whose individual components are likely to produce different responses within the organisms and/or interact producing additive, synergistic or antagonistic toxic effects. Most of these substances are potentially cytotoxic, genotoxic or carcinogenic, such as polycyclic aromatic hydrocarbons (PAHs). The Phrynops geoffroanus species ("Geoffroy's side-necked turtle", Schweigger, 1812) is widely distributed in tropical and temperate areas of South America. This species is commonly found in impacted areas, and polluted rivers that cross the urban area and receive domestic and industrial wastewater effluents. In these environments, freshwater turtles are exposed to ecological pressures that threaten their conservation and can influence the animal life habits and physiological conditions. The objective of this study was to evaluate the biochemical changes in various organs (liver, heart, lung, pancreas, brain, small and large intestines) of P.
3.Biomarkers in the freshwater bivalve Corbicula fluminea confined downstream a domestic landfill leachate discharge.
de Oliveira LF1, Santos C1, Dos Reis Martinez CB2. Environ Sci Pollut Res Int. 2016 Apr 4. [Epub ahead of print]
Landfills represent a severe environmental problem mainly due to the generation of leachates, and this study aimed to evaluate sublethal effects of a domestic landfill leachate in the freshwater bivalve Corbicula fluminea. Clams were submitted to in situ tests along a stream, at three sites, representing increasing distances from the leachate discharge (Pq1, Pq2, and Pq3), for 1, 5, and 15 days. The following biomarkers were analyzed in the gills and digestive glands: 7-ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST) activities, multixenobiotic resistance mechanism (MXR), total antioxidant capacity (TAC), reactive oxygen species (ROS), and lipid peroxidation (LPO). Metallothionein (MT) content was determined in the gills and DNA damage in hemocytes. The mortality rate of animals during in situ tests was reduced as the distance from the leachate discharge source increased. On the other hand, biomarker results showed sublethal effects on C.
4.Biological responses to contaminants in darters (Etheostoma spp.) collected from rural and urban regions of the Grand River, ON, Canada.
Diamond SR1, Sultana T1, Servos MR2, Metcalfe CD1. Comp Biochem Physiol B Biochem Mol Biol. 2016 Feb 26. pii: S1096-4959(16)30021-5. doi: 10.1016/j.cbpb.2016.02.005. [Epub ahead of print]
Urban and agricultural activities may introduce chemical stressors, including contaminants of emerging concern (CECs) and current use pesticides (CUPs) into riverine systems. The objective of this study was to determine if fish collected from various sites in the Grand River, ON, Canada show biomarkers of exposure to these classes of contaminants, and if the biomarker patterns vary in fish collected from urbanized and agricultural sites. Female rainbow darters (Etheostoma caeruleum) and female fantail darters (Etheostoma flabellare) were collected from the Grand River in June, 2014 for biomarker analysis from two urbanized sites and three agricultural sites. Over the same period of time, Polar Organic Chemical Integrative Samplers (POCIS) were deployed for 2weeks at each site to monitor for the presence of CUPs and CECs. Data on the liver somatic index for darters indicate site-specific differences in this condition factor (p<0.05). Significant differences in the levels of thiobarbituric acid reactive substances (TBARS) in gill tissue (p<0.