Sillence Martin N, Holt Kathi, Li Fang Ivy, Harris Patricia A, Coyle Mitchell, Fitzgerald Danielle M
School of Biology and Environmental Science, Queensland University of Technology, Brisbane, QLD 4001, Australia.
Equine Studies Group, Waltham Petcare Science Institute, Melton Mowbray LE14 4RT, UK.
Animals (Basel). 2025 Jul 17;15(14):2120. doi: 10.3390/ani15142120.
Ecdysterone controls moulting and reproduction in insects, crustaceans, and helminths. It is also produced by many plants, probably as an insect deterrent. The steroid is not made by vertebrates but has anabolic effects in mammals and could be useful for treating sarcopenia in aged horses. However, ecdysterone is banned in horseracing and equestrian sports, and with no limit of reporting, the risk of unintended exposure to this naturally occurring prohibited substance is a concern. To explore this risk, pasture plants and hay samples were analysed for ecdysterone content, as well as samples of blood, faeces, and intestinal mucosa from horses (euthanized for non-research purposes) with varying degrees of endo-parasite infestation. The variability in serum ecdysterone concentrations between different horses after administering a fixed dose was also examined. Ecdysterone was detected in 24 hay samples (0.09 to 3.74 µg/g) and several weeds, with particularly high concentrations in (244 µg/g) and (233 µg/g). There was a positive correlation between faecal ecdysterone and faecal egg counts, but no effect of anthelmintic treatment and no relation to the number of encysted cyathostome larvae in the large intestine mucosa. Certain horses maintained an unusually high serum ecdysterone concentration over several weeks and/or displayed an abnormally large response to oral ecdysterone administration. Thus, the risk of environmental exposure to ecdysterone is apparent, and several factors must be considered when determining an appropriate dosage for clinical studies or setting a reporting threshold for equine sports.
蜕皮甾酮控制昆虫、甲壳类动物和蠕虫的蜕皮及繁殖。许多植物也会产生蜕皮甾酮，可能是作为一种昆虫驱避剂。脊椎动物不会合成这种类固醇，但它在哺乳动物中具有合成代谢作用，可能有助于治疗老龄马匹的肌肉减少症。然而，蜕皮甾酮在赛马和马术运动中被禁用，而且由于没有报告限制，意外接触这种天然存在的违禁物质的风险令人担忧。为了探究这种风险，对牧场植物和干草样本的蜕皮甾酮含量进行了分析，同时也分析了来自不同程度内寄生虫感染的马匹（因非研究目的实施安乐死）的血液、粪便和肠黏膜样本。还检测了给不同马匹固定剂量的蜕皮甾酮后血清蜕皮甾酮浓度的变异性。在24份干草样本（0.09至3.74微克/克）和几种杂草中检测到了蜕皮甾酮，其中[植物名称1]（244微克/克）和[植物名称2]（233微克/克）中的浓度特别高。粪便中的蜕皮甾酮与粪便中的虫卵计数呈正相关，但驱虫治疗没有效果，且与大肠黏膜中包囊型杯状线虫幼虫数量无关。某些马匹在数周内血清蜕皮甾酮浓度一直异常高，和/或对口服蜕皮甾酮表现出异常大的反应。因此，环境中接触蜕皮甾酮的风险是明显的，在确定临床研究的合适剂量或设定马术运动的报告阈值时，必须考虑几个因素。
