Ethyl acetate extract of Lactococcus lactis KR-050L suppresses IL-6/STAT3 signaling in Hep3B cells and alleviates DSS-induced colitis in mice

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic inflammatory condition characterized by persistent intestinal inflammation. Despite advances in therapeutic strategies, effective long-term management remains challenging due to side effects and limited efficacy. Therefore, there is increasing interest in alternative approaches, including probiotics and bioactive compounds derived from microorganisms. In this study, we evaluated the effects of Lactococcus lactis KR-050L ethyl acetate extract (KR-050L-EtOAc) in a murine dextran sulfate sodium (DSS)-induced colitis model. KR-050L-EtOAc administration significantly attenuated disease severity, as demonstrated by reduced body weight loss, prevention of colon shortening, and improved histopathological features in a dose-dependent manner. In addition, KR-050L-EtOAc treatment decreased pro-inflammatory cytokine levels and preserved colonic tissue integrity. These results indicate that KR-050L-EtOAc exerts anti-inflammatory and tissue-protective effects in a DSS-induced colitis model. Given that this model reflects certain aspects of intestinal inflammation, further studies are required to determine the potential relevance of KR-050L-EtOAc in human IBD.