jiao Li

and 7 more

Background and Purpose: Abnormal activation of the NLRP3 inflammasome in macrophages is closely associated with Ulcerative colitis (UC), and targeting the NLRP3 inflammasome has been proposed as a potential therapeutic approach, but the underlying mechanism by which it regulates intestinal inflammation remains unclear. Anemoside B4 (AB4) has anti-inflammatory activity, but whether it alleviates UC by inhibiting the activation of NLRP3 inflammasome remains unclear. More importantly, the molecular targets of AB4 remain unknown. Experimental Approach: We explored the role of AB4 in the development of dextran sodium sulfate (DSS)-induced colitis in wild-type (WT) mice and its effect on NLRP3 inflammasome. We isolated intestinal macrophages and epithelial cells, and validated them in DSS-induced NLRP3-deficient (NLRP3-/-) mice. The target and molecular mechanism of AB4 were identified in LPS-induced macrophages in vitro and DSS-induced macrophage-specific CD1d depletion (CD1d-/-) mice in vivo. Key Results: This study showed that AB4 had a strong anti-inflammatory effect DSS-induced colitis in WT mice, whereas the protective effects were lost in NLRP3-/- mice. AB4 inhibited the activation of NLRP3 inflammasome in colonic macrophages without affecting intestinal epithelial cells. Mechanistically, AB4 might target CD1d thus reducing the AKT-STAT1-PRDX1-NF-κB signaling pathway, eventually inhibiting the activation of NLRP3 inflammasome. Macrophage-specific CD1d depletion had been shown to reverse the protective effect of AB4. Conclusions and Implications: Our data showed that AB4 attenuated DSS-induced colitis by inhibiting CD1d-dependent NLRP3 inflammasome activation in macrophages. Therefore, as a natural product with high safety index, AB4 might be considered a promising candidate drug for the treatment of colitis.