Evaluation of genotoxic effects of the herbicide dicamba using in vivo and in vitro test systems

Abstract

The genotoxic effects of the herbicide dicamba have been studied by measuring 1) the unwinding rate of liver DNA from intraperitoneally (i.p.) treated rats (fluorimetric assay); 2) DNA repair as unscheduled DNA synthesis (UDS) induced in cultured human peripheral blood lymphocytes (HPBL); and 3) sister chromatid exchanges (SCE) in HPBL. Results show that dicamba is capable of inducing DNA damage since it significantly increases the unwinding rate of rat liver DNA in vivo and also induces UDS in HPBL in vitro in the presence of exogenous metabolic activation (S-9 mix). Furthermore, dicamba causes a very slight increase in SCE frequency in HPBL in vitro.

Modulation of the genotoxicity of pesticides reacted with redox‐modified smectite clay

“…These data are consistent with results indicating dicamba is not mutagenic [Poole and Newell, 1977;Waters et al, 1980;Hrelia et al, 1994]. However, other studies found that dicamba induced DNA damage [Plewa et al, 1984;Perocco et al, 1990;Mohammed and Ma, 1999]. Dicamba reacted with reduced SWa-1 clay induced genomic DNA damage (Fig.…”

Evaluation of the genotoxic activity of dicamba and atrazine herbicides in several Mexican and South American varieties of sweetcorn (Zea mays L.)

“…Several studies in various cell types have shown that atrazine causes DNA damage (Ribas et al, 1995;Clements et al, 1997), whilst other studies do not report damage (Brusick, 1994;IARC, 1999). Moreover, at various concentrations, dicamba has also been reported to cause genetic damage (Perocco et al, 1990;Filkowski et al, 2003;Cenkci et al, 2010). Due to the controversy regarding the genotoxicity of dicamba, atrazine, and their mixture, the genotoxicity of two concentrations of Marvel (commercial mixture) was studied in: 1000-2000 and 2000-4000 ppm.…”

“…Corn crops are continuously exposed to various herbicides and some are genotoxic (Perocco et al, 1990;Calvalcante et al, 2008); therefore, the use of a biomonitor to detect genetic damage in corn is relevant. Use of the comet assay in meristematic sweetcorn nuclei is an important tool for assessing the genotoxic effect of commercial herbicides, as it is fast and relatively inexpensive.…”

Herbicides in Argentina. Comparative Evaluation of the Genotoxic and Cytotoxic Effects on Mammalian Cells Exerted by Auxinic Members

“…Similar observations were reported by Sorensen et al (2004Sorensen et al ( , 2005 on Dicamba-treated CHO cells cultured in the presence of reduced-clay smectites but not when the clay system was not included within the culture protocol. Both González et al (2006González et al ( , 2007González et al ( , 2009) and Perocco et al (1990) demonstrated the ability of the herbicide to induce SCEs in CHO cells and human lymphocytes with and without S9 fraction treated in vitro, respectively. The induction of alterations in the cell-cycle progression of different cellular systems including CHO cells and human lymphocytes were reported to occur after in vitro exposure to Dicamba (González et al, 2006(González et al, , 2009).…”

“…Furthermore, similar situation were observed in Escherichia coli and Bacillus subtilis when the reverse mutation assay was applied (Simmon, 1979;Leifer et al, 1981;Waters et al, 1981). Whereas the herbicide was unable to induce mitotic recombination in Saccharomyces cerevisiae (Zimmermann et al, 1984), negative and positive results were obtained for the induction of unscheduled DNA synthesis in human primary cells regardless of the presence or absence of a rat liver metabolic activation system (Simmon, 1979;Perocco et al, 1990). Induction of DNA single-strand breaks, estimated by the alkaline comet assay, was evaluated in CHO cells exposed in vitro to Dicamba.…”