In vivo and in vitro promutagen activation by Vicia faba of thiocarbamate herbicides molinate and butylate to products inducing sister chromatid exchanges in human lymphocyte cultures

Molinate and butylate treatments for 4 h of Vicia faba root tip meristems, showed that both thiocarbamate herbicides increased significantly SCE frequ ency. Direct treatments of molinate and butylate on human lymphocytes appli ed 24 h after the beginning of culture did not induce SCE. When S10 extract s of the Vicia roots, treated for 4 h with molinate and butylate tin vivo a ctivation) were added to lymphocytes (24 h after of the beginning of cultur e), SCE were induced in a concentration-response manner. The in vitro assay s, in which molinate and butylate was added at 48 h lymphocyte cultures for 3 h, showed a negative response, however, in the treatment where the S10 m etabolic mix was added the SCE frequencies were significantly different to the control, and the concentration-response relationship was not observed w ith molinate, but it was obtained with butylate. The results showed that bo th herbicides needed the V. faba metabolism to produce SCE in human lymphoc yte culture. (C) 1999 Elsevier Science B.V. All rights reserved.