In vitro evaluation of the toxicity of several dithiocarbamates using anEscherichia coli growth inhibition bioassay and the acetylcholinesterase inhibition test

Abstract

The industrial and sanitary use of dithiocarbamates (DTCs) is on the rise, and the synthesis of new derivatives has increased the field of their application. Both positive and negative pharmacological and toxicological effects have been documented for DTCs. The development and application of new DTCs must be accompanied by the study of their toxicity, beginning with the performance of simple and rapid biological screening tests. The objective of our study was to apply the IGEC biotest (inhibition of growth of Escherichia coli) and the acetylcholinesterase (AChE) inhibition test to a group of newly synthesized DTCs with possible applications in the area of public health. The substances studied were (−)-ephedrine-DTC, (+)-pseudoephedrine-DTC, N-ethylbenzyl-DTC, diethyl-DTC, and dimethyl-DTC, and the corresponding amines used in their synthesis: (−)-ephedrine, (+)-pseudoephedrine, N-ethylbenzylamine, diethylamine, and dimethylamine. The parameters for the minimal effective concentration tested (MEC), median effective concentration (EC50), and no observed effect concentration (NOEC) of each chemical were determined using the IGEC biotest. The AChE inhibition test was carried out for all the DTCs as well. Of the synthesized DTCs, (+)-pseudoephedrine-DTC showed the lowest toxicity (NOEC=30 μg mL−1 and EC50=301 μg mL−1) and N-ethylbenzyl-DTC showed the highest toxicity (EC50=26 μg mL−1). Although (−)-ephedrine-DTC exhibited a minimal inhibitory effect on AChE, the results obtained indicate a generalized absence of AChE inhibition for the DTCs. © 1998 John Wiley & Sons, Inc. Environ Toxicol Water Qual 13: 165–174, 1998