Norwegian Veterinary Institute, Department of Animal Health and Food Safety, Elizabeth Stephansens Vei, 1433As, Norway.
U.S. Dairy and Forage Research Center, Agricultural Research Service, U.S. Department of Agriculture, 1925 Linden Drive, Madison, WI, 53706, USA.
Exp Parasitol. 2022 Oct;241:108353. doi: 10.1016/j.exppara.2022.108353. Epub 2022 Aug 19.
Infections with Cryptosporidium spp. constitute a substantial public health burden and are responsible for widespread production losses in cattle herds. Reducing disease and shedding of Cryptosporidium spp. oocysts is an important One Health goal. There are very few therapeutic options available to treat cryptosporidiosis. Interest in plant bioactive compounds to mitigate the spread of anthelmintic resistance in ruminants has led to investigation of these phytocompounds against other parasitic taxa. Condensed tannins (CTs) are plant secondary metabolites that have shown potential against nematodes in vitro and in vivo but their applicability to Cryptosporidium spp. is comparatively under-explored. Cryptosporidium parvum infected human ileocecal colorectal adenocarcinoma (HCT)-8 cell cultures were treated with escalating doses of highly purified and well-characterized CTs from five plant species, big trefoil (Lotus pedunculatus), black currant (Ribes nigrum), sainfoin (Onobrychis viciifolia), white clover (Trifolium repens) and grapeseed (Vitis vinifera) for 44 h. Quantitative-PCR (qPCR) analysis revealed that none of the CTs examined demonstrated inhibitory potential against the parasite. Substantial inhibition of C. parvum by paromomycin was observed in positive controls in all assays (76.94-90.72% inhibition), proving the validity of the assay. Despite the lack of inhibition, these results represent an important step towards identifying alternative treatment options against this parasite.
隐孢子虫属感染构成了重大的公共卫生负担，是导致牛群广泛减产的原因。减少隐孢子虫属的感染和脱落是一个重要的人畜共患病目标。目前可用的治疗隐孢子虫病的方法非常有限。人们对植物生物活性化合物在减少反刍动物中驱虫药耐药性方面的兴趣，促使人们研究这些植物化合物对其他寄生虫类群的作用。单宁（CT）是植物次生代谢产物，已被证明对体外和体内的线虫具有潜在作用，但对隐孢子虫属的适用性相对较少。用从五种植物（大巢菜（Lotus pedunculatus）、黑加仑（Ribes nigrum）、苦马豆（Onobrychis viciifolia）、白三叶草（Trifolium repens）和葡萄（Vitis vinifera）中提取的高度纯化和特征明确的 CT 对感染隐孢子虫的人回肠结肠直肠腺癌（HCT）-8 细胞培养物进行了剂量递增处理，处理时间为 44 小时。定量 PCR（qPCR）分析显示，研究的 CT 均未显示出对寄生虫的抑制潜力。在所有试验中，阳性对照药物巴龙霉素对 C. parvum 的抑制作用均非常显著（抑制率为 76.94-90.72%），证明了该试验的有效性。尽管没有抑制作用，但这些结果代表着朝着确定针对这种寄生虫的替代治疗方法迈出了重要的一步。
