Endometritis is one of the main causes of bovine infertility, which causes serious economic losses to the industry. The endometrium is the first line of defense against invading microbial pathogens in the uterus. Andrographolide is the primary active component of A. paniculate, and has been shown to have anti-inflammatory and antioxidant effects. However, its effects on the LPS-induced signaling pathway in bovine endometrial epithelial cells (bEECs) have not been reported yet. The aim of this study was to investigate the anti-inflammatory effects and mechanism of andrographolide in the LPS-induced inflammatory response of bEECs. We found that andrographolide strongly reduced LPS-induced NO and iNOS expression. The production of cytokines that were upregulated by LPS was significantly suppressed. To investigate the anti-inflammatory mechanism of andrographolide, we examined the activation of Nrf2. The results shown that andrographolide inhibited the expression of Keap1 but increased the expression of Nrf2. The expression levels of target genes of Nrf2 including Ho-1 and Nqo-1 were increased by andrographolide. Taken together, these results suggest that andrographolide may serve as a candidate to protect against the LPS-induced inflammatory response by inducing Nrf2 activation.

子宫内膜炎是引起牛不育的主要原因之一，牛不育会给该行业造成严重的经济损失。子宫内膜是抵御子宫中微生物病原体入侵的第一道防线。穿心莲内酯是A. paniculate的主要活性成分，并已显示具有抗炎和抗氧化作用。然而，其对牛内膜上皮细胞（bEECs）中LPS诱导的信号通路的影响尚未见报道。这项研究的目的是研究穿心莲内酯在脂多糖诱导的bEECs炎症反应中的抗炎作用及其机制。我们发现穿心莲内酯可大大降低LPS诱导的NO和iNOS表达。LPS上调的细胞因子的产生被显着抑制。为了研究穿心莲内酯的抗炎机制，我们检查了Nrf2的激活。结果表明穿心莲内酯抑制Keap1的表达但增加Nrf2的表达。穿心莲内酯可提高包括Ho-1和Nqo-1在内的Nrf2靶基因的表达水平。