Evaluation of toxicity testing of 20 MEIC chemicals on Hep-2 cells using two viability endpoints

By Zanetti, C. - De Angelis, I. - Stammati, A.L. - Zucco, F.

The aim of the METC programme is to validate different in vitro testing protocols at an international level, comparing the results obtained for a series of compounds with the respective human in vivo data. The first 20 chemicals of the MEIC programme have been tested on a human epithelial cell line, Hep-2. Dose-response curves were determined by two viability endpoints, total protein content and percentage of LDH released, after exposure of confluent cultures for 24 hours. A good agreement was found in the LC50 ranking of the compounds obtained by the two parameters. Moreover, the effects of these compounds on the energetic pathway have been studied using a Clark electrode, at doses corresponding to the LC50 and just after the addition of the compound to the cells. A remarkable difference in the overall picture of toxicity is detected by assessing this specific target. The data obtained in this study are in good agreement with other, already published, MEIC project results.