Brown Algae Polysaccharides Alleviate Diquat-Induced Oxidative Stress in Piglets and IPEC-J2 Cells via Nrf2/ARE Signaling Pathway

Oxidative stress caused by weaning is widespread in pig breeding and poses a serious threat to the health of piglets. As a feed additive, Brown algae polysaccharides (BAPs) have a good application prospect and have antibacterial, anti-inflammatory, antioxidant, and antiviral activities. The present study was conducted to investigate the effects of BAP on oxidative stress in piglets. The results showed that BAPs alleviated the oxidative stress damage caused by diquat and improved the antioxidant capacity and intestinal barrier capacity of weaned piglets and IPEC-J2 cells. It is worth noting that BAPs also promoted the translocation of Nrf2 from the cytoplasm to the nucleus. These results provide a new way to illustrate the mechanism of BAPs alleviating oxidative stress in piglets. This study investigated the effect of Brown algae polysaccharides (BAPs) on diquat-induced oxidative stress in piglets and IPEC-J2 cells through Nrf2/ARE signaling pathway. In the in vivo model, 24 male piglets of the Duroc × Landrace × Large White breed were selected and divided into 4 groups (n = 6), including the CON group (basal diet), DIQ group (10 mg/kg Diquat), BAP group (1000 mg/kg BAP), and BAP+DIQ group (1000 mg/kg BAP + 10 mg/kg Diquat). Compared with the DIQ group, BAP improved growth performance and the BAP+DIQ group reduced the levels of IL-1β, IL-6, TNF-α, and DAO in plasma, increased VH and VCR, improved jejunal tissue morphology, decreased MDA levels, and increased T-AOC ( p < 0.05). Additionally, the BAP+DIQ group elevated mRNA levels of ZO-1 , and enhanced the protein levels of Occludin, Claudin1, CAT, SOD1, and HO-1 ( p < 0.05). In the in vitro model, the BAP+DIQ group decreased MDA levels, increased T-AOC, elevated mRNA levels of ZO-1 , CAT and SOD2 , as well as protein levels of Claudin1, SOD1, HO-1, and total Nrf2 compared with the DIQ group ( p < 0.05). Furthermore, BAP increased nuclear Nrf2 protein levels, and promoted the translocation of Nrf2 from the cytoplasm to the nucleus compared with the DIQ group ( p < 0.05). In conclusion, BAPs are crucial for enhancing piglets’ antioxidant capacity via Nrf2 pathway activation. These findings highlight BAP’s potential as a natural feed additive to mitigate oxidative stress and improve overall health in piglets. Further research is warranted to explore BAPs as a dietary supplement to support gut health and reduce oxidative stress.