Environmental and Molecular Mutagenesis 32:39–46 (1998) Cytogenetic Damage and Induction of Pro-Oxidant State in Human Lymphocytes Exposed In Vitro to Gliphosate, Vinclozolin, Atrazine, and DPX-E9636 Maria B. Lioi, 1 * Maria R. Scarfi, 2 Antonietta Santoro, 1 Rocchina Barbieri, 1 Olga Zeni, 1 Francesca Salvemini, 3 Dino Di Berardino, 4 and Matilde V. Ursini 3 1 Department of Animal Production Sciences, University of Basilicata, Potenza, Italy 2 National Research Council–IRECE, Naples, Italy 3 National Research Council–IIGB, Naples, Italy 4 Department of Animal Sciences, University of Naples ‘‘Federico II’’ Portici-Naples, Italy We analyzed chromosome aberrations (CAs), sister experimental conditions, each chemical compound chromatid exchanges (SCEs), mitotic index (MI), tested produced a dose-related increase in the per- and glucose 6-phosphate dehydrogenase (G6PD) cent of aberrant cells and an increase of SCE/cell. enzyme activity in human peripheral lymphocytes Furthermore, at the highest concentrations of vinclo- from three healthy donors exposed in vitro to differ- zolin, atrazine, and DPX-E9636, we observed a ent concentrations of gliphosate, vinclozolin, atra- significant reduction of the mitotic index. The in- zine, and DPX-E9636. The pesticides gliphosate, crease of G6PD activity in exposed lymphocyte cul- vinclozolin, and atrazine have been studied in a tures strongly indicated an induction of a pro-oxi- broad range of genetic tests with predominantly dant state of the cells as an initial response to pesti- conflicting or negative results, whereas little is cide exposure. Environ. Mol. Mutagen. 32:39–46, known about the genotoxicity of DPX-E9636. In our 1998  1998 Wiley-Liss, Inc. Key words: genotoxicity; chromosome aberrations; sister chromatid exchanges; glucose 6- phosphate dehydrogenase; oxidative stress; pesticides INTRODUCTION zyme activity. G6PD catalyzes the first and rate-limiting step of the hexose monophosphate (HMP) shunt and pro- Extensive studies have been carried out to evaluate the duces reducing power, in the form of NADPH, which is mutagenic potential of the pesticides gliphosate, vinclo- used by cells to drive the enzymatic reactions required to zolin, and atrazine in vitro and in vivo. Most of the reports remove reactive oxygen intermediates (ROIs) [Meister have indicated that gliphosate shows minimal genotoxic and Anderson, 1983] and is necessary to maintain the activity [Vigfusson and Vyse, 1980; Li and Long, 1988; intracellular pool of reduced glutathione (GSH), which is Rank et al., 1993], whereas controversial results have the main antioxidant molecule present in the cell cyto- been obtained on vinclozolin [Chiesara et al., 1982; Per- plasm [Meister, 1988]. Recent reports have clearly dem- occo et al., 1993; Hrelia et al., 1996] and atrazine [Adler, onstrated that the cell pro-oxidant state and, thus, GSH 1980; Meisner et al., 1992; Brusick, 1994] in different depletion, is always followed by increased G6PD activity, experimental systems ranging from bacterial to mamma- indicating that G6PD is functioning as an antioxidant en- lian assays. On the other hand, no data are available on zyme [Clancy et al., 1994; Banki et al., 1996; Ursini et the mutagenic potential of the recently introduced DPX- al., 1997]. Furthermore, it has been observed that eukary- E9636 in mammals. otic cells, bearing a genetically determined G6PD null The above considerations prompted us to improve our mutation, are extremely sensitive to oxidative stress [Pan- knowledge of the genotoxicity of the four pesticides and dolfi et al., 1995]. We therefore examined the cytogenetic to gain insight into their possible mechanism of action. Thus, we investigated the genotoxic potential of increas- ing concentrations of gliphosate, vinclozolin, atrazine, Contract grant sponsor: National Research Council Special Project R.A.I.S.A. and M.U.R.S.T 60%. and DPX-E9636 in in vitro cultures of human lympho- cytes by using as genetic endpoints chromosome aberra- *Correspondence to: Prof. Maria Brigida Lioi, Department of Animal Production Sciences, University of Basilicata, Via Nazario Sauro, 85, tion (CA) and sister chromatid exchange (SCE) frequen- 85100 Potenza, Italy. cies and, as an indicator of the change in the cell redox state, glucose 6-phosphate dehydrogenase (G6PD) en- Received 5 August 1997; Revised and accepted 5 April 1998.  1998 Wiley-Liss, Inc. EM-97-093R / 8i2e$$093r 07-06-98 14:57:56 wlema W Liss: EM