PT - JOURNAL ARTICLE AU - Hannu Kankaanranta AU - Pinja Ilmarinen AU - Xianzhi Zhang AU - Erkki Nissinen AU - Eeva Moilanen TI - Antieosinophilic Activity of Orazipone AID - 10.1124/mol.105.021170 DP - 2006 Jun 01 TA - Molecular Pharmacology PG - 1861--1870 VI - 69 IP - 6 4099 - http://molpharm.aspetjournals.org/content/69/6/1861.short 4100 - http://molpharm.aspetjournals.org/content/69/6/1861.full SO - Mol Pharmacol2006 Jun 01; 69 AB - Orazipone is a novel sulfhydryl-reactive compound that has been previously shown to reduce lung eosinophilia in guinea pigs and rats and to inhibit degranulation in mast cells and cytokine production in monocytes and T-cells. However, the effects of orazipone on granulocyte longevity are unknown. Orazipone and its derivative 3-(4-chloro-3-nitro-benzylidene)-pentane-2,4-dione (OR-2370) reversed interleukin-5-afforded survival of human eosinophils by inducing apoptosis. In contrast, orazipone did not affect granulocyte macrophage-colony-stimulating factor-induced survival of human neutrophils. The effect of orazipone on eosinophil apoptosis is different from that of glucocorticoids in that even high con-centrations of interleukin-5 were not able to overcome the effect of orazipone. Orazipone further enhanced spontaneous apoptosis as well as that induced by CD95 ligation without inducing primary necrosis. OR-2370-induced DNA fragmentation was shown to be dependent on caspases 3 and 6 and c-jun-N-terminal kinase, whereas extracellular regulated kinase, p38 mitogen-activated protein kinase, and phosphatidylinositol 3-kinase as well as caspases 4, 8, and 9 seem not to mediate its actions. Our results suggest that orazipone and its derivative OR-2370 possess strong antieosinophilic activity and thus may have anti-inflammatory efficacy in the treatment of asthma and/or allergic conditions.