Acute toxicity and effect of fenitrothion on liver esterase of fish

Abstract

The acute toxicity of fenitrothion (FNT) alone and combined with piperonyl butoxide (PBO) or triphenyl phosphate (TPP), and their effect on liver esterase (LE) activity of Gambusia holbrooki, Pseudorasobora parva and Oncorhynchus mykiss was studied in aquaria for 96h. The results indicated that fenitrothion is moderately toxic to the three species of fish tested, the toxicity being highest to O. mykiss followed by P. parva and G. holbrooki. Both FNT concentrations and the exposure time on the activity of LE and FNT (two way ANOVA P<0.05) caused more inhibition in G. holbrooki than P. parva. Pretreating fish with either PBO or TPP changed the acute toxicity level and LE sensitivity compared with those exposed to FNT alone. The acute toxicity level and susceptibility of LE to FNT was found to be inversely related. With additional studies P. parva and G. holbrooki have the potential to be used as bioindicator, and LE as biochemical biomarker of environmental pollution by FNT and other related compounds.


Key words/phrases: Fenitrothion, fish, liver esterase, synergists, toxicity


Abbreviations: FNT (fenitrothion), PBO (piperonyl butoxide), TPP (triphenyl phosphate), LE (liver es-terase), OP (organophosphate), ANOVA (analysis of variance), EEC (Economic Commission for Europe), WHO (World Health Organization), Glutathion (GSH), Glutathione S-transferase (GST), AchE (Acetylcho-linesterase), MFO (Mixed Function Oxidase).


SINET: Ethiop. J. Sci Vol.26(1) 2003: 23-29