Ibudilast-d7 is intended for use as an internal standard for the quantification of ibudilast by GC- or LC-MS. Ibudilast is an inhibitor of phosphodiesterase 4 (PDE4; IC50s = 54, 65, 239, and 166 nM for PDE4A-D, respectively).1 It is selective for PDE4 over PDE1, PDE7A, PDE7B, and PDE9A (IC50s = ≥10,000 nM for all) but does inhibit PDE3A, PDE3B, and PDE5A (IC50s = 1,600, 2,700, and 3,510 nM, respectively). Ibudilast inhibits LPS-induced production of TNF-α and fMLP-induced production of leukotriene B4 in isolated human whole blood (IC50s = 6.2 and 2.5 μM, respectively). It inhibits bronchospasm by 34% in a guinea pig model of leukotriene-mediated allergic bronchospasm when administered intravenously at a dose of 5 mg/kg.2 Ibudilast prevents increases in TNF-α, IL-1β, and IL-6 expression in the striatum in a mouse model of MPTP-induced Parkinson's disease.3 It also increases striatal expression of glial cell-derived neurotrophic factor (GDNF) in MPTP-treated and -untreated mice when administered at doses of 40 and 50 mg/kg, respectively, twice per day.
|1. Huang, Z., Liu, S., Zhang, L., et al. Preferential inhibition of human phosphodiesterase 4 by ibudilast. Life Sci. 78(23), 2663-2668 (2006).|2. Kreutner, W., Sherwood, J., and Rizzo, C. The effect of leukotriene antagonists, lipoxygenase inhibitors and selected standards on leukotriene-mediated allergic bronchospasm in guinea pigs. Agents Actions 28(3-4), 173-184 (1989).|3. Schwenkgrub, J., Zaremba, M., Joniec-Maciejak, I., et al. The phosphodiesterase inhibitor, ibudilast, attenuates neuroinflammation in the MPTP model of Parkinson's disease. PLoS One 12(7), e0182019 (2017).