Man-Society-Environment, Department of Environmental Sciences, University of Basel, Vesalgasse 1, 4051 Basel, Switzerland.
Sci Total Environ. 2010 Dec 15;409(2):326-33. doi: 10.1016/j.scitotenv.2010.10.017. Epub 2010 Nov 5.
Zearalenone (ZON) is one of the worldwide most common mycotoxins and exhibits estrogenic activity in the range of natural steroid estrogens such as 17β-estradiol (E2). The occurrence of ZON has been reported in drainage water, soil, wastewater effluents and rivers, but its ecotoxicological effects on fish have hardly been investigated. In this study the estrogenic potency of the ZON was compared to E2 in a recombinant yeast estrogen screen (rYES) and the effects of waterborne ZON exposure on reproduction, physiology and morphology of zebrafish (Danio rerio) were investigated in a 42-day reproduction experiment. E2 as well as ZON evoked a sigmoid concentration-response curve in the rYES with a mean EC(50) of 2 and 500 μg/L, respectively, resulting in an E2:ZON EC(50) ratio of 1:250. Exposure to ZON for 21 days reduced relative spawning frequency at 1000 and 3200 ng/L to 38.9 and 37.6%, respectively, and relative fecundity at 100, 320, 1000 and 3200 ng/L to 74.2, 41.7, 43.8 and 16.7%, respectively, in relation to the 21-day pre-exposure period. A 4.4 and 8.1 fold induction of plasma vitellogenin (VTG) was observed in male zebrafish at 1000 and 3200 ng/L ZON, respectively. Exposure to ZON did not affect fertility, hatch, embryo survival and gonad morphology of zebrafish. The results of this study demonstrate that although ZON possesses a moderate estrogenic potency in vitro, it exhibits a comparably strong effect on induction of VTG and reproduction in vivo. This indicates that ZON might contribute to the overall estrogenic activity in the environment and could therefore pose a risk for wild fish in their natural habitat.
玉米赤霉烯酮（ZON）是世界范围内最常见的霉菌毒素之一，其雌激素活性与天然甾体雌激素如 17β-雌二醇（E2）相当。ZON 已在排水、土壤、废水和河流中被报道，但它对鱼类的生态毒理学影响几乎没有被研究过。在这项研究中，我们在重组酵母雌激素筛选（rYES）中比较了 ZON 的雌激素效力，并用为期 42 天的繁殖实验研究了 ZON 暴露对斑马鱼（Danio rerio）繁殖、生理和形态的影响。E2 和 ZON 在 rYES 中引发了一个 S 型浓度-反应曲线，平均 EC50 分别为 2 和 500μg/L，导致 E2:ZON EC50 比值为 1:250。暴露于 ZON 21 天，1000 和 3200ng/L 组的相对产卵频率分别降至 38.9%和 37.6%，100、320、1000 和 3200ng/L 组的相对生育率分别降至 74.2%、41.7%、43.8%和 16.7%，与暴露前的 21 天相比。在 1000 和 3200ng/L ZON 组中，雄性斑马鱼血浆卵黄蛋白原（VTG）的诱导分别增加了 4.4 和 8.1 倍。ZON 暴露不影响斑马鱼的生育力、孵化、胚胎存活率和性腺形态。本研究结果表明，尽管 ZON 在体外具有中等的雌激素效力，但它在体内对 VTG 诱导和繁殖具有较强的作用。这表明 ZON 可能对环境中的整体雌激素活性有贡献，因此可能对其自然栖息地中的野生鱼类构成风险。
