Research Article Open Access
Volume 5 • Issue 1 • 1000250
J Environ Anal Toxicol
ISSN: 2161-0525 JEAT, an open access journal
Open Access Research Article
Olalekan, J Environ Anal Toxicol 2014, 5:1
DOI: 10.4172/2161-0525.1000250
*Corresponding author: Adeyemi Olalekan, Department of Environmental
Science, Federal University of Petroleum Resources, PMB 1221, Effurun, Nigeria,
Tel: +234(0)8037159452; E-mail: Adeyemi.olalekan@fupre.edu.ng
Received October 14, 2014; Accepted November 17, 2014; Published November
20, 2014
Citation: Olalekan A (2014) Biochemical Response of Clarias gariepinus to
Cypermethrin. J Environ Anal Toxicol 5: 250. doi: 10.4172/2161-0525.1000250
Copyright: © 2014 Olalekan A, This is an open-access article distributed under
the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and
source are credited.
Biochemical Response of Clarias gariepinus to Cypermethrin
Adeyemi Olalekan*
Department of Environmental Science, Federal University of Petroleum Resources, PMB 1221, Effurun, Nigeria
Keywords: Biochemical; Cypermethrin; Clarias gariepinus;
Cholinesterase; Cytochrome oxidase
Introduction
e use of pesticides has increased considerably to reduce the change
caused by pests to standing crops. Among these pesticides, synthetic
pyrethroids are commonly used because of their rapid biodegradability
and non-persistent nature. ese compounds, which frequently enter the
aquatic ecosystem through agricultural run-off and spraying operations
adversely, affect non-target animals such as fish [1-4].
Cypermethrin, a synthetic pyrethroid is a broad-spectrum
insecticide, used extensively in households, industrial and agricultural
fields [5] for control of several insect pests [6]. Due to indiscriminate
use, cypermethrin makes their entrance into natural water bodies
through agriculture run-off and ultimately affects the several non-
target aquatic organisms; for instance, it inhibits growth and several
metabolic activities of crustaceans [7], adversely affects fish metabolism
[8] and hematology [9], and thus adversely affects fish meat quality
and fish population [10]. Cypermethrin is also highly toxic against
freshwater snail L. accuminata and also affects both their metabolism
and reproduction [11,12]. Cypermethrin is less toxic to mammals,
birds and highly toxic to fish. Fishes are unable to metabolize the
pyrethroids efficiently [13]. Cypermethrin also affects the biochemical
enzyme by mode of neurotransmitters like acetylcholine (Ach) and
acetyl cholinesterase (AChE) activities.
Cypermethin is widely used in Nigeria by farmers for the treatment
of ectoparasitic disease and pests of maize, cotton, vegetables and
sorghum. e excessive use of the pesticide has always masked its
toxic effects on the aquatic environment [14,15]. Concentration of
cypermethrin in water bodies in Nigeria could be as high as between
45 mg/dL to 63 mg/dL [14]. Residues of these toxic chemicals
found in water, sediments, fish and other aquatic biota can pose a
risk to organisms, to predators and to human being. Pesticides at
high concentrations are known to reduce the survival, growth and
reproduction of fish and produce many visible effects on fish [16].
Srivastava and Kaushik [17] reported that the pesticides
accumulating in the vital organs, such as liver and muscle, cause
organ dysfunction, culminating in death of fishes. Activities of
certain enzymes, in fish, essential for metabolic functions are altered;
Disturbance of enzyme activity in fish serves as early indicator of
toxicant impact [18,19]. e lethal effect of cypermethrin is death which
usually occurs at concentration above 60 µg/L. In the present study,
highest level of cypermethrin is 20 µg/L and no mortality was recorded,
hence we consider the level a sub lethal level and the toxic effect a sub
lethal effect. erefore, the present work was designed to assess the
toxic effect of cypermethrin on African catfish, Clarias gariepinus, and
its sub lethal effects on its metabolism. Clarias gariepinus is a common,
freshwater, edible fish in Nigeria and some other parts of the world due
to their high nutritive food value.
Materials and Methods
Cypermethrin ([S, R]-N-α-cyno-3-phenoxybenzyl-(IR, IS,
cis, trans)-2, 2-dimethyl-3, (2, 2-dichlorovinyl) cylcopropane
carboxylate) manufactured by M/S Tropical Agrosystem Pvt. Ltd.
Chennai, India, and purchased from local market of Udu, Delta
State, Nigeria.
One hundred and fiſty juvenile species of C.gariepinus with the
mean weight of 61.2 ± 4.5 g and standard length mean length of 15.3
± 2.1 cm were used for the experiment. ey were purchased from
a reputable fish farm in Delta State, Nigeria. e fish were kept in
transparent plastic tanks filled with dechlorinated tap water and made
to acclimatize in laboratory conditions for two weeks. e experimental
fish were managed in accordance with the guidelines for handling
experimental animals. ey were fed (3% w/w) with commercial
feeds. Water quality was measured according to the method of APHA/
AWWA/WEF [20]. e temperature of the experimental water was
25.8 ± 0.6
°
C, pH was 7.3 ± 0.2 dissolved oxygen was 6.8 ± 0.3 mg/L, free
carbon dioxide was 5.8±0.5 mg/L and alkalinity was 104.9 mg/L. Water
was changed every day.
Abstract
The biochemical responses of Clarias gariepinus to cypermethrin was assessed in this study. C. gariepinus was reared in various
concentrations of cypermethrin-contaminated dechlorinated water (0, 5, 10, 15 and 20) µg/L over a period of five days and designated
A (Control), B, C, D and E respectively. The levels of protein and carbohydrate metabolites, protease, cholinesterase and cytochrome
oxidase of liver and muscle of fish were assayed. The total protein (TP) level of liver and muscle of Group E decreased by 20% and 29%
respectively relative to the control. Conversely, free amino acid (FAA) of liver and muscle of Group E increased by about 38% and 43%
respectively compared with the control. Relative to the control, the levels of glycogen and pyruvate of tissues of the liver and muscle of
Clarias gariepinus reared in contaminated water was significantly (p<0.05) lower while the level of lactate in the tissues was significantly
(p<0.05) higher. Activity of cholinesterase of the tissues of Group E animals was 1/3 that of control. In contrast, protease activity of tissue
of Group E animal was about 2 folds that of control. Cypermethrin inhibited activities of cholinesterase and cytochrome oxidase by a
mechanism that inhibited oxidative metabolism of carbohydrate and shifting to protein catabolism for energy requirement. Thus it may be
inferred that there is a tendency to shift the aerobic pathway to anaerobic pathway of fish respiration, to meet energy demands for the
physiological and metabolic activities augmented by Cypermethrin induced stress.
Journal of
Environmental & Analytical Toxicology
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ISSN: 2161-0525