Naslov
Effect of organophosphates malathion and temephos on cholinesterase activity in the earthworm Eisenia fetida (Oligochaeta, Lumbricidae)

Autori
Velki, Mirna ; Stepić, Sandra ; Jarić, Davorka ; Hackenberger, Branimir

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
NATO SfP 982590 project workshop : Abstracts / - , 2010

Skup
NATO SfP 982590 project workshop

Mjesto i datum
Dubrovnik, Hrvatska, 23.10.2010. - 26.10.2010

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
cholinesterase activity; temephos; malathion; hormesis

Sažetak
Earthworms are considered as important bioindicators of chemical toxicity in the soil ecosystem because of their important role in improving structure and fertility of the soil, their high biomass in soil, their contribution in recycling organic matter and their sensitive reactions toward environmental influences. Enzymatic, non-enzymatic and genetic biomarkers are a powerful and cost-effective tool to obtain information on the state of the environment and the effect of pollution on living biological resources. Generally, biomarkers such as cytochrome P450, cholinesterase activity, GST, oxidative stress, etc. have been identified in environmental pollution dealing with pesticides and organochlorine contaminants. But there are still many unsolved questions in biomarker applicability in real time environmental pollution monitoring. One of them is a question of effects of small so called sublethal doses. Whereas higher concentrations of a pollutant can easily be assessed with the acute (mortality) test, contaminated soils with lower (sublethal) pollutant concentrations require more sensitive test methods such as measurement of physiological status. In this study, adult Eisenia fetida earthworms were exposed to the sublethal concentrations of malathion and temephos using the contact filter paper test procedure. Since both malathion and temephos are organophosphate pesticides, its effects on earthworms were determined by measuring ChE inhibition – a known biomarker of exposure. The ChE activity was measured after a short time of exposure – 2 h. As expected, the lowest ChE activity was measured at the highest concentrations of malathion and temephos applied. More interestingly, at the 0.6 ng cm−2 (malathion) and 0.12 ng cm−2 (temephos) concentration the ChE activity significantly increased compared to control. Dose-response curves showed an inverted U-shape characteristic for hormesis. This hormetic-like effect could be important for health status of an earthworm as well for correct interpretation of biomonitoring results. Also, observed changes in cholinesterase activity in Eisenia fetida can be used as biomarker of pollution index at sublethal level in the environment.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA