Herein, the ultrasound-assisted extraction conditions affecting the yield of EUPS (Eucommia ulmoides polysaccharide) were analyzed using a Box-Behnken response surface design. The alleviation effect of EUPS on diquat-induced oxidative stress in mice was also studied. A maximum EUPS yield of 2.60% was obtained under the following optimized conditions: an extraction temperature of 63 °C, extraction time of 1 h, and ratio of liquid to raw materials of 22:1. EUPS exhibited strong 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical-scavenging ability (87.05%), 2′-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) radical-scavenging ability (101.17%), and hydroxyl radical-scavenging ability (62.92%). The administration of EUPS increased the activities of superoxide dismutase, catalase, and glutathione peroxidase and decreased malondialdehyde levels in the livers of mice exposed to diquat. EUPS may inhibit the downregulation of NAD(P)H:quinoneoxidoreductase 1 and heme oxygenase 1 mRNA expression in the livers of diquat-administered mice through the Nrf2-Keap1 signaling pathway. Moreover, the abundance of Firmicutes and Ligilactobacillus was enhanced, whereas that of Helicobacter decreased in the gut of the remaining groups of mice compared with that of the diquat-treated mice. Therefore, EUPS exhibited an antioxidant effect and improved oxidative stress and intestinal flora abundance in mice.

Coccidiosis is one of the most serious parasitic diseases in poultry, with Eimeria-induced apoptosis of IECs recognized as a key pathogenic mechanism. This review systematically delineates the molecular mechanisms governing this apoptotic process. The invasion process of Eimeria app. is mediated by the AMA1-RON2 moving junction complex and secreted effector proteins. An integrated model of apoptotic regulation is proposed. This model comprises the mitochondrial, death receptor, and endoplasmic reticulum stress pathways, which are coordinated by signaling hubs, such as PI3K/Akt, NF-κB, and JNK/p38 MAPK, and is further finely modulated by non-coding RNA networks. It is notable that the apoptosis during coccidial infection exhibits a biphasic pattern, where early inhibition supports parasite development and late activation facilitates parasite release and dissemination. Although potential therapeutic targets have emerged for these signaling pathways, how the host precisely switches between different apoptotic pathways remains a current core knowledge gap. Future research needs to thoroughly analyze the molecular logic of host–parasite interaction and ultimately lay a theoretical foundation for developing new strategies targeting the process of cell apoptosis for coccidiosis prevention and control.