Piclamilast

Piclamilast is a phosphodiesterase 4 (PDE4) inhibitor (IC₅₀ = 0.31 nM).¹ It is selective for PDE4 over PDE1, PDE2, PDE3, PDE5, and PDE7A in cell-free assays (IC₅₀s = >100, 40, >100, 14, and >10 μM, respectively).^2,3 Piclamilast inhibits superoxide production by guinea pig eosinophils and histamine-induced contraction in isolated guinea pig trachea (IC₅₀s = 24 and 2 nM, respectively).^1,4 It inhibits eosinophil, neutrophil, lymphocyte, and TNF-α accumulation in bronchoalveolar lavage fluid (BALF) from ovalbumin-sensitized rats (ED₅₀s = 23.8, 14.1, 19.5, and 14.4 μmol/kg, respectively).⁵ Piclamilast also inhibits ovalbumin-induced bronchoconstriction in a guinea pig model of asthma (ED₅₀ = 0.033 mg/kg).²

WARNING This product is not for human or veterinary use.

1. Ashton, M.J., Cook, D.C., Fenton, G., et al. Selective type IV phosphodiesterase inhibitors as antiasthmatic agents. The syntheses and biological activities of 3-(cyclopentyloxy)-4-methoxybenzamides and analogues. J. Med. Chem. 37(11), 1696-1703 (1994).

2. Ukita, T., Sugahara, M., Terakawa, Y., et al. Novel, potent, and selective phosphodiesterase-4 inhibitors as antiasthmatic agents: Synthesis and biological activities of a series of 1-pyridylnaphthalene derivatives. J. Med. Chem. 42(6), 1088-1099 (1999).

3. Nakata, A., Ogawa, K., Sasaki, T., et al. Potential role of phosphodiesterase 7 in human T cell function: Comparative effects of two phosphodiesterase inhibitors. Clin. Exp. Immunol. 128(3), 460-466 (2002).

4. Raeburn, D., Underwood, S.L., Lewis, S.A., et al. Anti-inflammatory and bronchodilator properties of RP 73401, a novel and selective phosphodiesterase type IV inhibitor. Br. J. Pharmacol. 113(4), 1423-1431 (1994).

5. Bundschuh, D.S., Eltze, M., Barsig, J., et al. In vivo efficacy in airway disease models of roflumilast, a novel orally active PDE4 inhibitor. J. Pharmacol. Exp. Ther. 297(1), 280-290 (2001).