Study of biochemical changes in tissues of Phrynops geoffroanus (Schweigger, 1812) (Testudines: Chelidae), as biomarkers of environmental contamination and exposure to benzo[a]pireno

• Grant number: 11/06680-8
• Support Opportunities: Scholarships in Brazil - Doctorate
• Effective date (Start): July 01, 2011
• Effective date (End): February 28, 2014
• Field of knowledge: Biological Sciences - Biochemistry - Metabolism and Bioenergetics
• Principal Investigator: Eduardo Alves de Almeida
• Grantee: Maria Isabel Afonso da Silva
• Host Institution: Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil

Abstract

Aquatic organisms are often exposed to a wide range of toxic chemicals, whose individual pollutants may produce different responses among the organisms and/or interact to produce additive toxic effects, synergistic or antagonistic. Most of these substances are potentially cytotoxic, genotoxic and carcinogenic, such as polycyclic aromatic hydrocarbons (PAHs). Environmental chemical contamination, associated with habitat loss and destruction, has resulted in the decline or disappearance of many populations. Among all vertebrates groups, the turtles are most threatened of extinction, and show concern conservation status. The species Phrynops geoffroanus (Schweigger, 1812), popularly known as "Geffroy's-Side-Necked-Turtle" is widely distributed in tropical and temperate areas from South America, being present in almost all Brazilian territory. This species is commonly found in impacted areas, such as polluted rivers which cross urban areas and receive domestic and industrial effluents. In these environments, the turtles are exposed to ecological pressures that threaten its conservation and can influence their life habits and physiological conditions. Studies on oxidative stress and biochemical responses to pollutants in reptiles are scarce in the literature, especially in aquatic turtles. In this context, assessing the effect of contaminants on physiological and biochemical level is of great importance for better understanding of how these animals respond to environmental pollutants exposure. The aim of this study is assess the biochemical changes in tissues (liver, pancreas, heart, lung, brain, small intestine, large intestine and kidney) of Phrynops geoffroanus as biomarkers of environmental contamination by anthropogenic activities (urban and industrial effluents) and exposure to benzo[a]pyrene, a model compound of PAHs. For this, we'll analyze the systems responses related to the xenobiotics biotransformation of phase I and phase II, activities of major antioxidant enzymes and MDA levels, indicative of oxidative stress, as biomarkers for biomonitoring of pollutants impact. Based on enzymatic responses are expected to understand the biochemical effects of contaminants in turtle's specific organs, and to characterize the biomarkers and tissues sensitivity to pollutants such as benzo[a]pyrene. Thus, we intent to understand the biochemical mechanisms of detoxification and antioxidant defense in Phrynops geoffroanus species, which will be very important for understanding the physiology of turtles in general, and contribute in designing better strategies for the group conservation. (AU)