This paper below by Gasnier and others should be read alongside the paper by Orton et al on "endocrine activity." The latter authors selected 134 commonly used pesticides, and examined 37 of them for "receptor mediated anti-androgenic potency". Of these, 14 suspected of having AR antagonism were confirmed as anti-androgenic, together with 9 previously untested pesticides. In addition, 7 further compounds were conformed as being dangerous from the point of view of endocrine disruption. So 30 out of the 37 chemicals examined were potentially dangerous -- and were shown to have AR antagonism in vitro tests.
Glyphosate (number 22) was shown in the paper in the group of "known inactive androgen receptor antagonists", and one might assume therefore that the chemical is therefore harmless, or at least not damaging in this particular area. However, as Gasnier et al have pointed out in 2009, glyphosate is hardly ever sold as glyphosate, but normally as Roundup -- in various formulations. And these formulations, because of the adjuvants and other components used in the "recipes", are clearly toxic and are endocrine disruptors at sub- agricultural doses.
Both groups of authors call for urgent in vivo studies to confirm what they have found in the laboratory. There are two messages coming out of this work:
1. Roundup -- in various formulations -- is an endocrine disruptor with toxic effects, and it should be banned because of the residues known to exist in transgenic feed from HT (RR) crops.
2. Because 30 out of the 37 examined pesticides in the Orton et al study were found to have negative effects as endocrine disruptors, it is certain that there is a "cocktail" of these residues in the food supply chain, and that this must be linked to the decline in male reproductive health and sperm counts.
Danger signals, loud and clear -- but is anybody listening?
Céline Gasnier, Coralie Dumont, Nora Benachour, Emilie Clair, Marie- Christine Chagnon, Gilles-Eric Séralini
Toxicology 262 (2009) 184–191
Available online 17 June 2009
Glyphosate-based herbicides are the most widely used across the world; they are commercialized in different formulations. Their residues are frequent pollutants in the environment. In addition, these her- bicides are spread on most eaten transgenic plants, modiﬁed to tolerate high levels of these compounds in their cells. Up to 400 ppm of their residues are accepted in some feed. We exposed human liver HepG2 cells, a well-known model to study xenobiotic toxicity, to four different formulations and to glyphosate, which is usually tested alone in chronic in vivo regulatory studies. We measured cytotoxicity with three assays (Alamar Blue® , MTT, ToxiLight® ), plus genotoxicity (comet assay), anti-estrogenic (on ER, ER) and anti-androgenic effects (on AR) using gene reporter tests. We also checked androgen to estrogen conversion by aromatase activity and mRNA. All parameters were disrupted at sub-agricultural doses with all formulations within 24 h. These effects were more dependent on the formulation than on the glyphosate concentration. First, we observed a human cell endocrine disruption from 0.5 ppm on the androgen receptor in MDA-MB453-kb2 cells for the most active formulation (R400), then from 2 ppm the transcriptional activities on both estrogen receptors were also inhibited on HepG2. Aromatase tran- scription and activity were disrupted from 10 ppm. Cytotoxic effects started at 10 ppm with Alamar Blue assay (the most sensitive), and DNA damages at 5 ppm. A real cell impact of glyphosate-based herbi- cides residues in food, feed or in the environment has thus to be considered, and their classiﬁcations as carcinogens/mutagens/reprotoxics is discussed.
In conclusion, according to these data and the literature, G-based herbicides present DNA damages and CMR effects on human cells and in vivo. The direct G action is most probably ampliﬁed by vesi- cles formed by adjuvants or detergent-like substances that allow cell penetration, stability, and probably change its bioavailability and thus metabolism (Benachour and Séralini, 2009). These deter- gents can also be present in rivers as polluting contaminants. The type of formulation should then be identiﬁed precisely in epidemi- ological studies of G-based herbicides effects (Acquavella et al., 2006). Of course to drive hypotheses on in vivo effects, not only dilution in the body, elimination, metabolism, but also bioaccumu- lation and time-ampliﬁed effects (Benachour et al., 2007b) should be taken into account. These herbicides mixtures also present ED effects on human cells, at doses far below agricultural dilu- tions and toxic levels on mitochondrial activities and membrane integrity. These doses are around residual authorized levels in transgenic feed, and this paper is the ﬁrst clear demonstration of these phenomena in human cells. The in vivo ED classiﬁcation of G- based herbicides with this molecular basis must be now carefully assessed.
Frances Orton, Erika Rosivatz, Martin Scholze, Andreas Kortenkamp
10 February 2011
Orton F, Rosivatz E, Scholze M, Kortenkamp A 2011. Widely Used Pesticides with Previously Unknown Endocrine Activity Revealed as in Vitro Anti-Androgens. Environ Health Perspect :-. doi:10.1289/ehp. 1002895
Background: Evidence suggests that there is widespread decline in male reproductive health and anti-androgenic pollutants may play a significant role. There is also a clear disparity between pesticide exposure and endocrine disrupting data, with the majority of the published literature focused on pesticides that are no longer registered for use in developed countries.
Objective: The aim of this study was to utilise estimated human exposure data to select pesticides to test for anti-androgenic activity, focusing on highest use pesticides.
Methods: We used European databases to select 134 candidate pesticides based on highest exposure, followed by a filtering step according to known or predicted receptor mediated anti-androgenic potency, based on a previously published quantitative structure-activity relationship (QSAR) model. In total, 37 pesticides were tested for in vitro androgen receptor (AR) antagonism. Of these, 14 were previously reported to be AR antagonists (“active”), 4 were predicted AR antagonists using the QSAR, 6 were predicted to not be AR antagonists (“inactive”), and 13 with unknown activity, which were “out of domain” and therefore could not be classified with the QSAR (“unknown”).
Results: All 14 pesticides with previous evidence of AR antagonism were confirmed as anti-androgenic in our assay and 9 previously untested pesticides were identified as anti-androgenic (dimethomorph, fenhexamid, quinoxyfen, cyprodinil, λ-cyhalothrin, pyrimethanil, fludioxonil, azinphos-methyl, pirimiphos-methyl). In addition, 7 compounds were classified as androgenic.
Due to estimated anti-androgenic potency, current use, estimated exposure, and lack of previous data, we strongly recommend that dimethomorph, fludioxonil, fenhexamid, imazalil, ortho- phenylphenol and pirimiphos-methyl be tested for anti-androgenic effects in vivo. The lack of human biomonitoring data for environmentally relevant pesticides presents a barrier to current risk assessment of pesticides on humans.