Earthworm’s Acetylcholinesterase as Biomarker to Monitor the Effects of Pesticides

Document Type : Original Article

Author

Central Pesticides Laboratory, Sabahia Station Alexandria, Egypt

Abstract

The effect of three insecticides; methomyl (carbamate), dimethoate and malathion (organophosphates) and one cupper-containing fungicide (Cupper hydroxide) was evaluated in vivo on acetylcolinesterease (AChE) isolated from earthworm Lumbricus terrestirs to achieve a better understanding of AChE responses to agrochemicals in L. terrestirs. Three values of median lethal concentrations of the four compounds were determined from the acute toxicity (0.1, 0.5 of LC50 and the LC50). The three insecticides at the three levels of LC50 inhibited AChE activity and the inhibition was dose dependent. Methomyl at LC50 level had the highest AChE inhibition (98.9%) after 7 days of exposure to contaminated soil. Cupper hydroxide which contains cupper element showed induction of AChE activity at the three levels of LC50s. The maximal induction was at 0.5 of LC50  (27.7% followed with 0.1  (20.3%) and the value of LC50  (6.8%) compared with control.
Our results further support the use of AChE as an indicator of pesticide contamination, to be included in a battery of biomarkers for monitoring soil toxicity.