PEA reduces MC degranulation, inflammation, and extracellular trap formation. (A) PEA (IP, 20 mg/kg per day) administration for 14 days significantly reduced percentage of degranulating MCs observed with TB staining in the skin of female HbSS mice compared with Veh treatment. (B-C) PEA significantly reduced tryptase and IL-6 in skin releasate of HbSS mice compared with Veh treatment, which is constitutively elevated compared with HbAA mice. (D) SAP is constitutively increased in the circulation of HbSS mice compared with HbAA mice, and SAP is significantly reduced after 14-day PEA (IP, 20 mg/kg per day) administration. (E) Cytokine microarray revealed a significant reduction in pro-inflammatory and mast cell–mediating cytokines IL-1ß, IL-5, IL-6, IL-10, IL-12, IL-17, IFN-γ, and TNFα in skin releasate of female PEA-treated HbSS mice compared to female vehicle-treated HbSS mice. (F) Overnight treatment of MCs from HbSS mouse skin with TNF-α (1 ng/mL) and hemin (40 μM) increased MCET formation, indicated by explosion of nuclear content observed with Syto 13 and Sytox Orange staining of DNA. Mixed CB₁ and CB₂ agonist CP55,940 (30 μM) attenuated MCET formation. PEA treatment (10 and 30 μM) dose-dependently reduced MCET formation. Mean ± SD. In panels A-D, data were analyzed using 2-way ANOVA and the Tukey post hoc multiple comparisons test. In panel E, data were analyzed using unpaired Student 2-tailed t test. In panel F, scale bar = 40 μm. ∗P < .05; ∗∗P < .01; ∗∗∗P < .001; ∗∗∗∗P < .0001. Age: 3.5 to 5.0 months. For panels A-D, n = 4-6; panel E, n = 9 per condition. GM-CSF, granulocyte-macrophage colony-stimulating factor; IFN-γ, interferon gamma; MCP1, monocyte chemoattractant protein; MIP-1α, macrophage inflammatory protein-1; RANTES, regulated on activation normal T-cell expressed and secreted protein; TB, toluidine blue.