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

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 x Landrace x 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-1 beta, IL-6, TNF-alpha, 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.