Authors: Martin Emily Medlin, Till Rebecca Louise, Sheats Mary Katherine, Jones Samuel L
Journal: Frontiers in veterinary science
Summary
Dysregulated neutrophil function—manifesting as excessive adhesion, migration, and reactive oxygen species production—drives tissue damage in several equine conditions including asthma, colitis, laminitis, and gastric glandular disease, yet conventional NSAIDs inadequately suppress these inflammatory mechanisms whilst carrying significant adverse effect risks. Researchers investigated whether misoprostol, a PGE1 analogue already used clinically as a gastroprotectant in horses, might inhibit neutrophil-mediated inflammation by elevating intracellular cyclic AMP levels; they exposed isolated neutrophils from 12 healthy horses to varying misoprostol concentrations before stimulating them with inflammatory mediators (LTB4, CXCL8, PAF, LPS, immune complexes, and PMA), measuring adhesion, chemotaxis, and respiratory burst via fluorescence assays and luminol-enhanced chemiluminescence. Misoprostol pretreatment significantly suppressed LTB4-induced adhesion and chemotaxis in a concentration-dependent manner, substantially reduced CXCL8- and PAF-induced migration, and potently inhibited LPS-, immune complex-, and PMA-triggered reactive oxygen species production in vitro. These findings suggest that misoprostol's activation of E-prostanoid receptors could represent a novel anti-inflammatory strategy for conditions where neutrophil-driven tissue damage predominates, offering particular appeal given the drug's established safety profile and dual gastroprotective action in equine patients receiving NSAIDs.
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Practical Takeaways
- •Misoprostol, already used clinically as a gastroprotectant in horses, may have additional anti-inflammatory benefits through neutrophil modulation in inflammatory conditions like laminitis and colitis
- •These in vitro findings suggest misoprostol could potentially reduce tissue damage from dysregulated neutrophil activity when NSAIDs alone are insufficient, though in vivo clinical trials are needed
- •Further research is required before misoprostol can be recommended as a novel anti-inflammatory therapy, but this work provides a mechanistic rationale for investigating its use beyond GI protection
Key Findings
- •Misoprostol pretreatment significantly inhibited LTB4-induced neutrophil adhesion in a concentration-dependent manner
- •Misoprostol inhibited LTB4-, CXCL8-, and PAF-induced neutrophil chemotaxis in isolated equine neutrophils
- •Misoprostol reduced LPS-, IC-, and PMA-induced ROS production in equine neutrophils in a concentration-dependent manner
- •EP receptor targeting by misoprostol potently suppresses multiple equine neutrophil effector functions in vitro