Bioaccumulations of aluminum and the effects of chelating agents on different organs of Cirrhinus mrigala

Abstract

The study of biological indicator organisms may be more informative than analyzing water or sediments for monitoring heavy metal pollution in the aquatic environment. Non-essential elements enter into the animals and accumulate at the different organs so that chelating agents are most versatile and effective antidotes to eliminate the metals toxicities. The aim of our present study is to find out bioaccumulations of aluminum and the effects of chelating agents DFO and DFP in Muscle, gill, kidney, brain and liver tissues of Cirrhinus mrigala by using inductively coupled atomic emission spectrometry (ICP-AES). This study determined that the accumulation pattern of aluminum is muscle > gill > kidney > brain > liver. The present result suggests that DFO and DFP reduce the aluminum concentration in the tissues of C. mrigala fish and both are efficient chelators. Aluminum toxicity is a widespread problem in all forms of life, including humans, animals, fish, plants, and causes wide spread degradation of the environment and health.

Introduction

Aluminum is the most abundant metal and comprises about 8% of the Earth's crust and it is found in combination with oxygen, silicon, fluorine and other elements in soil, rocks, clays and gems (Sigel and Sigel, 1988) although it has no known biological function (Farina et al., 2002). Presently, aluminum utensils are widely used throughout the world, especially in developing countries (Lin et al., 1997). The use of such tools may increase an individual's aluminum exposure, particularly when these are used with salty, acidic or alkaline foods (Sharma and Mishra, 2006). Additionally, aluminum and its salts are commonly used in daily life as it they are perceived to be non-toxic and quickly excreted by urine. However, this element can have negative impact human and animal health (Osinska et al., 2004). Aluminum is potentially toxic to humans and the Agency for Toxic Substances and Disease Registry (ATSDR) (Agency for Toxic, 2008), reported that aluminum is distributed mainly in the bone, liver, testis, kidneys and brain. In patients on dialysis (Alfrey et al., 1976) or on long-term total parenteral nutrition (Klein, 1993), this metal accumulates in different organs. The toxicological effects of aluminum in human include encephalopathy (Ward et al., 1978) bone disease, anemia and skeletal system disease (Short et al., 1980). Furthermore, aluminum is possibly a contributing factor in the development of Alzheimer's disease (Gupta et al., 2005). However, this remains controversial (Campbell, 2002, Flaten, 2001).

Chelating agents possess the common ability to form complexes with heavy metals and thereby prevent or reverse the binding of metallic captions to body legends. Chelating therapy is recommended for heavy metal poisoning and these metals exert their toxic effects by combining with one or more reactive groups essential for normal physiological functions. Deferroxamine (DFO) and deferiprone (DFP) chelating agents are designed specifically to compete with these groups for the metals and thereby prevent or reverse toxic effects and enhance the excretion of metals. DFO is the principal product of the various side amines obtained from Streptomyces pilosus (Keberle, 1964). In the present study Cirrhinus mrigala fish was selected for experimental investigation because it is highly sensitive to various toxicants, as well as being a perennially abundant, fast breeding fish, which tolerates a wide range of water quality parameters and temperatures. These fish are also commercially and nutritionally important.

Inductively couple plasma atomic emission spectroscopy (ICP-AES) as employed in this report, is an important technique to study the trace elements at molecular level in various biological samples. It is particularly effective in this context due to its high sensitivity for detecting the major trace elements (Karl and Peter, 1995).