Toxic potential of municipal solid waste leachates in transgenic Drosophila melanogaster (hsp70-lacZ): hsp70 as a marker of cellular damage.

Municipal solid wastes (MSWs) are one of the major sources of environmental pollution. Leachates from these wastes might contaminate the water sources and affect quality of environment. The study was carried out to determine the possible toxic effects of leachates from MSW in transgenic Drosophila melanogaster (hsp70-lacZ). Third instar larvae exposed to 1.0-3.0% of these leachates at different time intervals were examined for hsp70 expression, oxidative stress enzyme activities, proteotoxicity, tissue damage along with effect on emergence and reproduction. Maximum hsp70 expression was observed in the larvae exposed to highly acidic leachates. Overwhelming of hsp70 expression in the exposed larvae caused a concomitant decline in total protein content and a significant elevation in oxidative stress enzymes and lipid peroxidation (LPO) product. The leachates caused a significant delay in emergence of flies and affected the reproductive performance of the flies at the tested concentrations. The present study highlights the toxic potential of MSW leachates and the advantage of Drosophila as a model to evaluate the impact of leachates at organismal and cellular levels, also advocating Hsp70 as the first tier indicator of toxicity.