<i>Coreopsis Tinctoria Nutt</i> . Polyphenols Protect Intestinal Barrier in Depressed Mice by Modulating TLR4/MYD88/NF‐κB Pathway

Depression is a mental disorder strongly associated with gut dysfunction. This study investigated the protective effects of Coreopsis tinctoria Nutt. polyphenolic (CTNP) extract against intestinal barrier damage in a mouse model of depression induced by chronic unpredictable mild stress (CUMS). CTNP alleviated depressive-like behaviors and enhanced intestinal integrity, as evidenced by decreased serum levels of lipopolysaccharide (LPS) and diamine oxidase (DAO), as well as increased expression of tight junction proteins (Occludin, ZO-1, and MUC2). Furthermore, CTNP reduced the production of pro-inflammatory cytokines (IL-1β, TNF-α, and IL-6) in colon tissue, potentially through inhibition of the TLR4/MYD88/NF-κB signaling pathway. These findings elucidate the underlying mechanism of CTNP's protective effects in depression-related intestinal injury and provide both theoretical insights and practical implications for future research.