USDA ARS Poisonous Plant Research Laboratory, 1150 E. 1400 N., Logan, UT 84341, USA.
Toxicon. 2011 Jan;57(1):157-61. doi: 10.1016/j.toxicon.2010.11.009. Epub 2010 Nov 20.
It is well understood that water hemlock tubers are highly toxic to animals and to humans. However, this is the first time that immature seed from (Cicuta maculata) has been implicated in livestock poisoning. Nine mature Hereford cows from a herd of 81 died in northwestern Utah after ingesting immature seed heads of water hemlock (Cicuta maculata) in late summer. No obvious signs of poisoning were reported as all nine were found dead near the banks of the stream where water hemlock was found. Upon discovery of the dead cows, the remaining 72 cows were immediately removed from the pasture and no further losses occurred. Field necropsy of 3 of the dead cows and follow-up serology and histopathological examination of selected tissues did not identify any bacterial or viral causes. History of ingestion of large quantities of water hemlock seed, the acute nature of the deaths, chemical comparison of seed with toxic tubers and follow-up mouse bioassay testing supported the diagnosis of water hemlock poisoning. Seed heads collected from the neighboring pasture upstream and across the fence from the poisoned cattle and tubers collected from grazed plants were chemically analyzed and found to contain cicutoxin, and high levels of two cicutol-like derivatives (cicutol-#1 and #2) as well as other unidentified polyacetylene compounds. Seeds and tubers from suspected plants were semi-quantified and compared to archive samples of highly toxic tubers used in previous experiments. The immature hemlock seed contained less cicutoxin (0.01 times), but 9.5 and 22.5 times more cicutol-#1 and cicutol-#2 respectively, compared to the archive sample. Tubers from the grazed plants contained 4.6 times more cicutoxin and 9.8 and 18.8 times more cicutol-#1 and cicutol-#2 respectively, compared to the archive sample. Mouse bioassays with water extracts of immature seed and tubers from grazed plants demonstrated both were highly toxic and of greater toxicity when compared to archived sample.
众所周知，水毒芹块根对动物和人类有剧毒。然而，这是首次有报道称未成熟的水毒芹种子（Cicuta maculata）可引起牲畜中毒。在犹他州西北部，81 头牛的一个牛群中，9 头成年赫里福德牛在夏末食用水毒芹（Cicuta maculata）未成熟的种子头后死亡。由于所有 9 头牛都在发现水毒芹的溪流岸边被发现死亡，因此没有报告明显的中毒迹象。在发现死牛后，立即将其余 72 头牛从牧场上移走，此后没有再发生损失。对 3 头死牛进行的野外剖检以及随后对选定组织的血清学和组织病理学检查均未发现任何细菌或病毒病因。大量摄入水毒芹种子的病史、死亡的急性性质、种子与有毒块根的化学比较以及随后的小鼠生物测定试验支持水毒芹中毒的诊断。从相邻牧场上游和受毒牛围栏对面收集的种子头以及从放牧植物上采集的块根进行了化学分析，发现含有毒芹毒素以及两种类似 cicutol 的衍生物（cicutol-#1 和 #2）以及其他未鉴定的多炔化合物。对疑似植物的种子和块根进行了半定量分析，并与以前实验中使用的高毒性块根的档案样本进行了比较。未成熟的毒芹种子中含有较少的毒芹毒素（为档案样本的 0.01 倍），但 cicutol-#1 和 cicutol-#2 的含量分别高 9.5 和 22.5 倍。来自放牧植物的块根中含有 4.6 倍的毒芹毒素以及 9.8 和 18.8 倍的 cicutol-#1 和 cicutol-#2。用放牧植物的未成熟种子和块根的水提取物进行的小鼠生物测定表明，两者均具有高度毒性，且毒性比档案样本更大。
