BACKGROUND: Diet plays a significant role in mitigating inflammation, with lettuce and its polyphenols showing potential for improving inflammatory conditions. However, research on the material basis and mechanisms of action remains unclear. RESULTS: This study investigated the primary components and anti-inflammatory effects of the new lettuce cultivar Binfen-1, which is rich in polyphenols and may offer enhanced health benefits. There were 65 metabolites with significant changes in Binfen-1 by metabolomics, comprising mainly polyphenols. Meanwhile, the high-polyphenol lettuce extract (HPLE) from Binfen-1 demonstrated superior antioxidant and anti-inflammatory effects in vitro. Moreover, HPLE showed a significant improvement in mice with dextran sodium sulfate-induced ulcerative colitis. By integrating network pharmacology with high-performance liquid chromatographic quantitative results, isoquercitrin and chlorogenic acid were identified as the core active substances in HPLE, and the PI3K-Akt, MAPK, and JAK-STAT pathways were the key anti-inflammatory pathways for HPLE, supported by mRNA validation and molecular docking predictions. CONCLUSION: The core anti-inflammatory substances in HPLE were isoquercitrin and chlorogenic acid, with the key anti-inflammatory pathways being the PI3K-Akt, MAPK, and JAK-STAT pathways. These findings substantially propel the understanding of the therapeutic potential of lettuce in the treatment of inflammatory diseases. (c) 2025 Society of Chemical Industry.