Reparixin (Repertaxin) is a potent inhibitor of both CXCL8 receptors CXCR1/2, it inhibits weakly CXCR2-mediated cell migration (IC50=100 nM), whereas it strongly blocks CXCR1-mediated chemotaxis (IC50=1 nM).

CXCR1:1 nM, CXCR2:100 nM, CXCR1 (wild-type):5.6 nM (in L1.2 cells), CXCR1 (Ile43Val):80 nM (in L1.2 cells)

L1.2 Cell suspension (1.5-3×106 cells/mL) is incubated at 37°C for 15 min in the presence of vehicle or of Reparixin (1 nM-1 μM) and next seeded in triplicates in the upper compartment of the chemotactic chamber. Different agonists are seeded in the lower compartment of the chamber at the following concentrations: 1 nM CXCL8, 0.03 nM fMLP, 10 nM CXCL1, 2.5 nM CCL2, 30 nM C5a. The chemotactic chamber is incubated at 37°C in air with 5% CO2 for 45 min (human PMNs) or 2 h (monocytes). At the end of incubation, the filter is removed, fixed, and stained and five oil immersion fields at high magnification (100×) are counted for each migration well after sample coding. L1.2 migration is evaluated using 5 μM pore size Transwell filters.

C57BL/6J mice (8-10 weeks old/20-25 g) are used. The subcutaneous administration of Reparixin (30 mg/kg) is performed 60 minutes before cerebral ischemia induction. The animals are divided into the following three experimental groups: Sham (i.e., the group in which the arteries are visualized, but there is no occlusion of the middle cerebral artery), Vehicle (i.e., the group pre-treated with the vehicle, phosphate buffer solution, 60 minutes before MCAo) and Reparixin (i.e., the group pre-treated with the drug 60 minutes before MCAo). To evaluate neurological signs secondary to MCAo, the animals are assessed with the SHIRPA battery 24 h after reperfusion.