Avertin affects murine colitis by regulating neutrophils and macrophages

Luteolin ameliorates DSS-induced colitis in mice via suppressing macrophage activation and chemotaxis

OBJECTIVES

Luteolin, known for its multifaceted therapeutic properties against inflammatory diseases, holds potential for addressing the unmet need for effective treatments in ulcerative colitis (UC), a prevalent subtype of inflammatory bowel disease (IBD). This study aimed to comprehensively assess luteolin's therapeutic efficacy in a dextran sulfate sodium (DSS)-induced colitis mouse model, shedding light on its anti-UC mechanisms.

METHODS

Our investigation encompassed in vivo assessments of luteolin's therapeutic potential against DSS-induced colitis through rigorous histopathological examination and biochemical analyses. Furthermore, we scrutinized luteolin's anti-inflammatory prowess in vitro using lipopolysaccharide (LPS)-stimulated RAW264.7 cells and primary peritoneal macrophages. Additionally, we quantitatively evaluated the impact of luteolin on C-C motif chemokine ligand 2 (CCL2)-induced macrophage migration employing Transwell and Zigmond chambers. Furthermore, cellular thermal shift assay (CETSA), drug affinity responsive target stability (DARTS) assay, and molecular docking were employed to identify potential therapeutic targets of luteolin and investigate their binding sites and interaction patterns.

RESULTS

Luteolin demonstrated therapeutic potential against DSS-induced colitis by ameliorating colitis symptoms, restoring intestinal barrier integrity, and inhibiting proinflammatory cytokine production in the colonic tissues. Moreover, luteolin demonstrated robust anti-inflammatory activity in vitro, in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and primary peritoneal macrophages. Notably, luteolin suppressed the phosphorylation of IKKα/β, IκBα, and p65, along with preventing IκBα degradation in LPS-treated RAW264.7 cells and peritoneal macrophages. Furthermore, luteolin impaired the migratory behavior of RAW264.7 cells and peritoneal macrophages, as evidenced by reduced migration distance and velocity of luteolin-treated macrophages. Mechanistically, luteolin was found to antagonize IKKα/β, subsequently inhibiting IKKα/β phosphorylation and the activation of NF-κB signaling.

CONCLUSION

Luteolin emerges as a promising lead compound for the clinical therapy of colitis by virtue of its ability to ameliorate DSS-induced colitis, antagonize IKKα/β, suppress NF-κB signaling, and impede macrophage activation and migration.

Cyclosporine A-Encapsulated pH/ROS Dual-Responsive Nanoformulations for the Targeted Treatment of Colitis in Mice

Inflammatory bowel disease (IBD) is a frequently occurring disease that seriously influences the patient's quality of life. To decrease adverse effects and improve efficacy of therapeutics, nanomedicines have been widely used to treat IBD. However, how to thoroughly release payloads under an inflammatory microenvironment and synergistic therapy of IBD need to be further investigated. To address this issue, cyclosporine A (CsA)-loaded, folic acid (FA)-modified, pH and reactive oxygen species (ROS) dual-responsive nanoparticles (FA-CsA NPs) were fabricated using pH/ROS-responsive material as carrier. The prepared FA-CsA NPs had spherical shape and uniform size distribution and could smartly release their payloads under acid and/or ROS microenvironment. In vitro experiments demonstrated that FA-CsA NPs can be effectively internalized by activated macrophages, and the internalized NPs could down-regulate the expression of proinflammatory cytokines compared to free drug or nontargeted NPs. In vivo experiments verified that FA-CsA NPs significantly accumulated at inflammatory colon tissues and the accumulated NPs obviously improved the symptoms of colitis in mice without obvious adverse effects. In conclusion, our results provided a candidate for the targeted treatment of IBD.