For centuries, pesticides have been used in agriculture to enhance food production by eradicating unwanted insects and controlling disease vectors. Among common pesticides are organophosphorus compounds which are widely used in agriculture, medicine and industry. The main advantages of pyrethroids that made it successively replacing organophosphrus pesticides are their photostability, high effectiveness even in low concentration, easily disintegration, and low toxicity in birds and mammals [1
Fish and various other aquatic organisms are extremely susceptible to pyrethroids as the 96
h Lc50 value determined in laboratory tests, generally lies below 10
μg/l. In addition, deltamethrin is based on pyrethroids that have established significantly lower rates of metabolism and removal in fish than those recorded for birds and mammals [2
Effluents of agricultural and industrial processes contain highly toxic chemicals like pesticides that lead to pollution of aquatic environments including rivers, ponds and lakes. The accumulation and persistence of insecticide and pesticides in the aquatic environment constitute a threat to biological life, as witnessed by the chronic and acute poisoning of fish and other aquatic organisms [3
Deltamethrin has very good residual activity for outdoor uses and for indoor uses; it has a high toxicity to fish under laboratory environment. However, in field conditions under normal conditions of use, fish may not harmed. Deltamethrin had an impact on aquatic herbivorous insects. This impact led to an increase of algae.
The World Health Organisation reported that roughly 3 million cases of pesticide poisoning occur annually that result in 22 000 deaths worldwide. Many of these chemicals are mutagenic [4
] linked to the development of cancers or may lead to development deficits [5
species are air breathing fishes due to the presence of accessory assistant respiratory organs beside the gills enabling it to survive for long time outside the water, otherwise debilitating hypoxic environments [6
]. Catfish Clarias
is freshwater, belonging to the genus Clarias
. There are 32 species of catfish belonging to genus Clarias
are known in Africa. Clarias lazera
and Clarias gariepinus
are the most popular members of the inland water fishes found in Egypt.
is known locally as karmout and is commonly found in Lake Nasser and all Nile branches and streams [7
]. These species are tolerant to a wide range of water and laboratory conditions and has detritivorous behaviour. This means that the fish can be in contact with xenobiotics from different ways of interacting with algae from stone or sediment. These characteristics make this particular species an interesting model for ecotoxicological and biochemical studies. Moreover Catfish are valuable bio-indicators of contamination because of their large distribution, being open swimmers, capacity to react against ecological pollution and food source for human.
The long-term biological hazards associated with the use of organochloride, organophosphate and carbamate pesticides propelled the introduction of a new generation of pesticides with a lesser degree of persistence. In this direction, the use of pyrethroids as insecticidal and antiparasitic formulations has markedly increased as a viable substitute and account for over 30% of insecticides used globally [8
Deltamethrin [((s)-a-cyano-3-phenoxybenzyl(R1-R2)-3-(2,2 dibromvinyl)-2,2 dimethylcyclo-propancarboxylate] is one of the most important widely used pyrethroids pesticide and insecticides, since the application of pyrethroid as insecticide and antiparasitary preparations has been accepted on a large scale for agricultural purposes and very markedly increased during last 10–15
years; even though it is already known that this insecticide is highly toxic to fish and various other aquatic organisms [9
The presence of low deltamethrin concentration in water has sublethal effects such as altered energy metabolism and ionic regulation. It is a synthetic type two of pyrethroids, which has a wide range of application in industrial and agricultural purposes. It is also used as an alternative pesticide in animal health, in vector control, and in public health [10
Among the most commonly used biomarkers, those related to oxidative stress assume an important position, being frequently used both in environmental monitoring and laboratory assays [11
Rates or amounts of reactive oxygen species (ROS) production can be increased by the presence of a wide range of natural and man-made xenobiotics [12
The stimulation of free radical production, induction of lipid peroxidation, and disturbance of the total antioxidant capability of the body are mechanisms of toxicity for most pesticides, including organochlorines and pyrethroids [13
]. Consequently, the antioxidant defences are potentially interesting biomarkers to pesticides while enhanced lipid peroxidation, a consequence of oxidative deterioration of membrane lipids, is generally referred to an index of oxidative stress. Moreover, ROS alter protein structure or function and Amino acid side-chains can be irreversibly modified into aldehyde or ketone groups (carbonylation) which can lead to protein aggregation, inactivation or degradation, these changes in protein carbonylation process are a biochemical perturbation resulting from oxidative stress [14
Few reports have demonstrated the induction of oxidative stress by pyrethroids, such as cypermethrin and fenvalerate [15
], while the effect of deltamethrin on catfish have not been investigated. Induction of oxidative stress is one of the main mechanisms of many pesticides action [13
]. The damage to membrane lipids, protein and DNA is the endpoint biomarker of oxidative stress-inducing effects of pesticides [16
]. Various adaptive and compensatory responses are also induced as a result of exposure to deltamethrin in fish [17
α-tocopherol, a fat-soluble vitamin, is a major antioxidant, responsible for terminating free radical chain reactions that result from the oxidation of polyunsaturated fatty acids (PUFA) [18
]. Therefore, it was suggested an increased amount of α-tocopherol supplementation to inhibit cellular lipid peroxidation of PUFA.
In order to protect the tissue from oxidant injury, antioxidant enzymes are also present in the biological system. Blomhoff [19
] reported that when animals are exposed to a dietary oxidative stress, they react with compensatory induction of endogenous antioxidants. Supplementation of dietary components like vitamin E [tocopherols and tocotrienols) and vitamin C, etc. lowered lipid peroxidation, protein oxidation and the incidence of various morbidities or mortalities; induced catalase activity, reduced the oxidative stress in rat.
The contamination of aquatic ecosystem by pesticides has gained increasing attention in recent decades. The acute and chronic exposure and accumulation of these chemicals can result in tissue burdens that produce adverse effects not only in the exposed organisms, but also organisms including human beings; therefore, it seems essential to study detrimental effects of such hazardous pollutants so as to formulate the strategies for safe guarding aquatic organisms.
The present study was designed to assess the effect of two doses of deltamethrin on several biochemical parameters on serum and tissues of catfish (Clarias gariepinus) to establish this species as a model for biochemical studies. Also, we aimed to investigate the effects of deltamethrin on some oxidative biomarkers (MDA and catalase activities) and some serum biochemical parameters, alanine transaminase (ALT), aspartate transaminase (AST), total protein, albumin, urea and creatinine. In order to better understand fish response to deltamethrin exposure and try to use α-tocopherol in order to restore the alteration of the changes in the oxidative and biochemical parameters which are dysregulated by deltamethrin.