Lipoxins are specialized pro-resolving mediators (SPMs) derived from arachidonic acid that promote resolution of inflammation. In contrast to prostaglandins and leukotrienes, lipoxins are characterized by:

• A Promoting neutrophil recruitment via CXCR2
• B Inhibiting neutrophil recruitment and promoting macrophage efferocytosis of apoptotic neutrophils ✓
• C Activating leukotriene B4 synthesis from macrophages
• D Increasing vascular permeability via H1 receptor

Explanation

Lipoxins (LXA4 and LXB4) are produced at the termination phase of acute inflammation, primarily via transcellular biosynthesis between neutrophils and platelets (or eosinophils). They act as endogenous 'stop signals' for inflammation: they inhibit neutrophil chemotaxis and adhesion (via ALX/FPR2 receptor), promote apoptosis of infiltrated neutrophils, and stimulate macrophage efferocytosis (clearance of apoptotic cells) — facilitating tissue restoration. Resolvins and protectins are other SPMs derived from omega-3 fatty acids with similar pro-resolution roles.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.