Glyphosate is the active ingredient in broad-spectrum herbicide formulations used in agriculture, domestic area and aquatic weed control worldwide. Its market is growing steadily concurrently with the cultivation of glyphosate-tolerant transgenic crops and emergence of weeds less sensitive to glyphosate. Ephemeral and lentic waters near to agricultural lands, representing favorite habitats for amphibian reproduction and early life-stage development, may thus be contaminated by glyphosate based herbicides (GBHs) residues. Previous studies on larval anuran species highlighted increased mortality and growth effects after exposure to different GBHs in comparison to glyphosate itself, mainly because of the surfactants such as polyethoxylated tallow amine present in the formulations.

Nevertheless, these conclusions are not completely fulfilled when the early development, characterized by primary organogenesis events, is considered.

In this study, we compare the embryotoxicity of Roundup^® Power 2.0, a new GBH formulation currently authorized in Italy, with that of technical grade glyphosate using the Frog Embryo Teratogenesis Assay–Xenopus (FETAX). Our results evidenced that glyphosate was not embryolethal and only at the highest concentration (50 mg a.e./L) caused edemas. Conversely, Roundup^® Power 2.0 exhibited a 96 h LC50 of 24.78 mg a.e./L and a 96 h EC50 of 7.8 mg a.e./L. A Teratogenic Index of 3.4 was derived, pointing out the high teratogenic potential of the Roundup^® Power 2.0.

Specific concentration-dependent abnormal phenotypes, such as craniofacial alterations, microphthalmia, narrow eyes and forebrain regionalization defects were evidenced by gross malformation screening and histopathological analysis. These phenotypes are coherent with those evidenced in Xenopus laevis embryos injected with glyphosate, allowing us to hypothesize that the teratogenicity observed for Roundup^® Power 2.0 may be related to the improved efficacy in delivering glyphosate to cells, guaranteed by the specific surfactant formulation. In conclusion, the differences in GBH formulations should be carefully considered by the authorities, since sub-lethal and/or long-term effects (e.g. teratogenicity) can be significantly modulated by the active ingredient salt type and concentration of the adjuvants. Finally, the mechanistic toxicity of glyphosate and GBHs are worthy of further research.

草甘膦是广谱除草剂配方中的活性成分，广泛用于农业，家庭区域和全球范围内的水生杂草防治。它的市场与耐草甘膦转基因作物的种植以及杂草对草甘膦不那么敏感的出现同时稳定增长。因此，草甘膦类除草剂残留物可能污染了农田附近的短暂和片状水，这是两栖动物繁殖和生命早期发育的最爱栖息地。先前有关幼虫无水生物种类的研究强调，与草甘膦本身相比，接触不同的GBH后死亡率和生长效应增加，这主要是因为制剂中存在表面活性剂，例如聚乙氧基化牛脂胺。

然而，当考虑到以原发器官发生事件为特征的早期发育时，这些结论仍未完全实现。

在这项研究中，我们比较综述的胚胎^®功率2.0，当前者在意大利新GBH配方，与使用青蛙胚胎致畸Assay-工业级草甘膦非洲爪蟾（FETAX）。我们的结果表明，草甘膦不是胚胎致死的，仅在最高浓度（50 mg ae / L）时才引起水肿。相反地，综述^®功率2.0表现出24.78毫克AE / L的96小时LC50和7.8毫克AE / L的96小时EC 50。3.4致畸指数推导，指出了农达的高潜在致畸^®电源2.0。

通过总体畸形筛查和组织病理学分析证明了特定的浓度依赖性异常表型，例如颅面改变，小眼症，窄眼和前脑区域性缺陷。这些表型是一致与那些在证明非洲爪蟾胚胎注射草甘膦，让我们假设致畸的综述观察^®Power 2.0可能与特定表面活性剂配方保证的草甘膦向细胞的递送效率提高有关。总之，主管部门应仔细考虑GBH配方的差异，因为活性成分的盐类型和佐剂浓度可显着调节亚致死作用和/或长期作用（例如致畸性）。最后，草甘膦和GBHs的机械毒性值得进一步研究。