In the mammary glands, production of antimicrobial components and formation of less-permeable tight junctions (TJs) are important for safe milk production. Previously, we reported that local heat treatment of udders using disposable heating pad enhances the components of innate immunity in lactating goat mammary glands. Gingerol is a polyphenol present in ginger that can induce heat-like effects. However, oral administration of polyphenols causes a decrease in biological activity through conjugation and metabolic conversion. Here, we investigated the effects of gingerol on antimicrobial components and TJs by topically applying it to lactating goat udders. Gingerol application increased the somatic cell count, cathelicidin-2 concentration, and proportion of polymorphonuclear cells in the milk and interleukin-8 production. Moreover, gingerol treatment enhanced β-defensin-1 production in milk, cultured mammary epithelial cells, and cultured somatic cells. Contrastingly, gingerol treatment did not affect the concentrations of blood-derived components (Na+, albumin, and IgG) in the milk or the TJ barrier function of cultured mammary epithelial cells. These findings suggest that the topical application of gingerol, similar to local heat treatment, to udders enhances the components of innate immunity in mammary glands. These findings may be useful for the prevention of mastitis in milk-producing animals and, hence, safe and stable dairy production.

中文翻译：

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姜辣素局部应用对泌乳山羊乳腺先天免疫成分的潜在影响。

在乳腺中，抗菌成分的产生和渗透性较小的紧密连接 (TJ) 的形成对于安全产奶非常重要。此前，我们报道过使用一次性加热垫对乳房进行局部热处理可增强泌乳山羊乳腺的先天免疫成分。姜酚是生姜中存在的一种多酚，可以产生类似热的作用。然而，口服多酚会通过结合和代谢转化导致生物活性降低。在这里，我们通过将姜辣素局部应用于哺乳山羊乳房来研究姜辣素对抗菌成分和 TJ 的影响。姜酚的施用增加了体细胞计数、cathelicidin-2 浓度、牛奶中多形核细胞的比例以及白细胞介素 8 的产生。此外，姜辣素处理可增强牛奶、培养的乳腺上皮细胞和培养的体细胞中β-防御素-1的产生。相比之下，姜辣素处理不会影响乳汁中血液来源成分（Na+、白蛋白和 IgG）的浓度或培养的乳腺上皮细胞的 TJ 屏障功能。这些发现表明，与局部热处理类似，局部使用姜辣素可以增强乳腺的先天免疫成分。这些发现可能有助于预防产奶动物的乳腺炎，从而实现安全稳定的乳制品生产。