Evaluation of Cytotoxicity of the First Twenty MEIC Chemicals by Using Haemolysis of Human Erythrocytes as an Endpoint

The cytotoxicity of the first twenty chemicals on the MEIC list was evaluated by determining the haemolytic activity of the chemicals. All the tested chemicals, except malathion, were haemolytic. With digoxin and sodium fluoride, however, the maximum degree of haemolysis achieved remained less than 50%. The EC10 for the chemicals varied from 0.38mM (digoxin) to 4,830mM (ethylene glycol). Comparing our data for the first ten MEIC chemicals with data obtained with other in vitro test systems, they correlated well with data reported for human lymphocytes (r = 0.93), rat hepatocytes (r = 0.98) and 3T3 cells (r = 0.95). However, in comparison with these tests, the haemolysis assay was less sensitive. The EC10 for the first ten MEIC chemicals correlated rather well (r = 0.84) with human lethal blood concentrations, but the haemolysis assay underestimated the toxicity of most of the chemicals and particularly underestimated the toxicity of digoxin.