Anti-inflammatory activity of Chlorella polysaccharide AHP.

Current medications for inflammatory bowel disease (IBD) are associated with various side effects. Researches had shown that bioactive substances (such as polysaccharides) exhibited anti-inflammatory activity, immunomodulatory activity and the property of the regulation of gut microbiota, which could contribute to the repair of colonic tissue and the improvement of intestinal health. The bioactive substances provided a new direction for developing safe, effective and novel therapeutic strategies. Therefore, the objective of this study was to evaluate the efficacy and safety of Chlorella polysaccharide AHP for the treatment of Caco-2 cell injury and ulcerative colitis in mice. This study investigated the anti-inflammatory activity of polysaccharide extracted from Chlorella (AHP) and its mechanisms through in vitro and in vivo experiments. In vitro, AHP significantly reduced reactive oxygen species (ROS) level, suppressed apoptosis and downregulated the levels of proinflammatory factors in dextran sulfate sodium (DSS)-induced Caco-2 cells, demonstrating antioxidant and anti-inflammatory effects. In vivo, AHP alleviated pathological damage of colon, decreased oxidative stress and levels of pro-inflammatory cytokines, enhanced expression of tight junction proteins and repaired intestinal mucosal barrier in mice with DSS-induced colitis. Furthermore, AHP modulated gut microbiota composition and levels of related metabolites, contributing to its anti-inflammatory activity through microecological regulation. These findings indicated that AHP mitigated DSS-induced cell injury and colonic damage via multiple pathways, confirming its potent anti-inflammatory properties through in vitro and in vivo experiments. This study provided important theoretical basis for exploring new treatments of IBD with bioactive substance AHP and developing functional foods based on AHP.