Exposure to environmental toxicants that affect the immune system and overall health of many mammals is mostly unavoidable. One of the more common substances is the mycotoxins, especially carcinogenic aflatoxin (AF)B1 which also causes immune suppression/dysregulation in exposed hosts. The present study analyzed the effects of naturally occurring levels of AFB1 on apoptosis of healthy bovine and camelid neonatal neutrophils (PMN) that were isolated both before and after host consumption of colostrum. Cells from bovine and camel neonates (n = 12 sets of PMN/mammal/timepoint) were exposed for 24 h to a low level of AFB1 (i.e. 10 ng AFB1/ml) and then intracellular ATP content and caspase-3, -7, and -9 activities (determined by bioluminescence) were assessed. The results indicated a significant lessening of intracellular ATP content and equivalents of luminescence intensity in AFB1-treated PMN in all studied samples, i.e. isolated pre-and post-colostrum consumption. In contrast, caspase-3, -7, and -9 activities in both pre- and post-colostrum consumption bovine and camelid PMN were noticeably increased (∼>2-fold). The damaging effects of AFB1 were more pronounced in bovine neonate PMN than in camelid ones. These results showed that camelid or bovine neonatal PMN collected pre- and post-colostrum are sensitive (moreso after consumption) to naturally occurring levels of AFB1. While merits of colostrum are well known, its failure to mitigate toxic effects of AFB1 in what would translate into a critical period in the development of immune competence (i.e. during the first few days of life in bovine and camelid calves) is surprising. The observed in vitro toxicities can help clarify underlying mechanisms of immune disorders caused by AFs in animals/humans.

中文翻译：

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初乳不能防止AFB1对牛/骆驼科新生儿嗜中性白细胞的损害。

不可避免地会暴露于影响许多哺乳动物免疫系统和整体健康的环境毒物。霉菌毒素是一种较常见的物质，尤其是致癌性黄曲霉毒素（AF）B1，它也会在暴露的宿主中引起免疫抑制/调节异常。本研究分析了天然存在的AFB1水平对食用牛初乳前后的健康牛和骆驼科新生儿中性粒细胞（PMN）凋亡的影响。将来自牛和骆驼新生儿的细胞（n = 12组PMN /哺乳动物/时间点）暴露于低水平的AFB1（即10 ng AFB1 / ml）中24小时，然后暴露于细胞内ATP含量和caspase-3，-7，评估了-9活性（由生物发光确定）。结果表明，在所有研究的样品中，AFB1处理的PMN中的细胞内ATP含量和等效发光强度均显着降低，即初乳前后的分离消耗。相比之下，牛初乳和骆驼科PMN摄入前后的caspase-3，-7和-9活性均明显增加（约2倍）。牛新生PMN中AFB1的破坏作用比骆驼科动物更明显。这些结果表明，初乳前后采集的骆驼科或牛新生儿PMN对AFB1的天然水平敏感（食用后更是如此）。虽然初乳的优点众所周知，但它未能减轻AFB1的毒性作用，而这将成为免疫能力发展的关键时期（即 在牛和骆驼犊牛的生命的最初几天中）令人惊讶。所观察到的体外毒性可以帮助阐明动物/人中由房颤引起的免疫疾病的潜在机制。