Concentration Effects of Selected Insecticides on Brain Acetylcholinesterase in the Common Carp (Cyprinus carpio L.)

Abstract

: The differential inhibition of acetylcholinesterase (AChE) by organophosphate (OP) and carbamate (C) is followed by the distinct duration of exposure effect on common carp AChE. Hence, in the present study in vivo exposure period effect and in vitro concentration-response of chlorfenvinphos, chlorpyrifos diazinon, and carbofuran were investigated on Cyprinus carpio L. AChE. Individuals of 1-year-old carp were exposed for 96 h to different concentrations of insecticides-after which AChE activity was measured in the brain. The highest concentrations of carbofuran (2.44 mg • L -1 )-chlorfenvinphos (2.9 mgL -1 ), and diazinon (2.5 mg.L -1 ) killed at] the test animals after only 4 h, although there was no statistically significant difference from the control group's brain AChE activity. The lowest concentration significantly inhibited brain AChE after 96 h. Chlorfenvinphos was the most potent inhibitor in vivo and chlorpyrifos the least active inhibitor after 96 h of exposure time. In vitro experimentation with the same pesticide indicated that several concentrations inhibited 50% of the AChE activity (I 50 ) ranging from 4.1 x 10 -7 to 8.12X 10 -4 M in both single inhibitory action and joint inhibitory effect. The results suggest that in biomonitoring programs carp brain AChE can be a good diagnostic tool for chronic OP nd C pollution.

Acute toxicity and haematological changes in common carp (Cyprinus carpio) caused by diazinon exposure

“…The LC 50 values computed from the graph figure 1. made between probit of kill and log 10 concentrations were 18.57 mg/l for 24 h, 14.87 mg/l for 48 h, 12.29 mg/l for 72 h and finally 9.76 mg/l for 96 h. The value recorded in this study was higher than the value recorded (0.72x10 -4 ppm) for the fry of this fish by Dembele et al (2000). Office of Pesticide Programs (2000) reported 96 h LC 50 values of diazinon for sheephead minnow (Cyrinodon virginica) as 1.47 mg/l and for fathead minnow (Pimephales minnow) as 7.8 mg/l.…”

Acetylcholinesterase enzyme activity in carp brain and muscle after acute exposure to diafuran

“…For all diafuran concentrations, for the three species, there was a decrease in the AChE activity in brain and muscle tissue. In the same way, common carp (6-10 cm) exposed to carbofuran (99%) presented lower brain AChE activity (Dembelé et al, 2000). Three different size groups (fry: 3-4, fingerlings: 6-8 and sub-adults: 10-12cm) of Nile tilapia (Oreochromis niloticus) exposed to carbosulfan (carbamate) 1, 4, 8 e 10 mg L -1 for 48 h presented lower brain AChE activity with the increasing concentration of carbosulfan (Chandrasekara & Pathiratne, 2007).…”

“…Common carp exposed to 0.05 mg L -1 of carbofuran for 48 h showed 80% inhibition in brain AChE activity (Bertrand et al, 1998), and exposure to 50 mg L -1 in goldfish inhibited 23% AChE activity in skeletal muscle (Bretaud et al, 2000). Common carp exposed to 0.1, 0.22 mg L -1 carbofuran (99%) showed 27.8 and 75% AChE activity inhibition, respec- (Dembelé et al, 2000). In addition, AChE activity inhibition in brain of Nile tilapia exposed to 10 µg L -1 carbofuran (48 h) was 59% (Chandrasekara & Pathiratne, 2007).…”

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“…In vivo inhibition or induction of biomarkers can be considered as a good tool to assess the exposure and the potential effects of pesticides on living organisms (Ozmen et al, 1999;Dembélè et al, 2000;Sturm et al, 2000;McLoughlin et al, 2000;Rendon-von Osten et al, 2005;Varo et al,2007).Thefish plays an increasingly important role in the monitoring of water pollution because it responds with great sensitivity to changes in the aquatic environment (Hernández-Moreno, 2010). Furthermore, changing of enzyme activities is used to determine the presence of pesticides in water (Chandrasekara and Pathiratne, 2005;Varo et al, 2007).…”