A rat air pouch model for evaluating the efficacy and selectivity of 5-lipoxygenase inhibitors. Export

@article{citeulike:2432058, abstract = {The 5-lipoxygenase (5-LOX) pathway has been associated with a variety of inflammatory diseases including asthma, atherosclerosis, rheumatoid arthritis, pain, cancer and liver fibrosis. Several classes of 5-LOX inhibitors have been identified, but only one drug, zileuton, a redox inhibitor of 5-LOX, has been approved for clinical use. To better evaluate the efficacy of 5-LOX inhibitors for pharmacological intervention, a rat model was modified to test the in vivo efficacy of 5-LOX inhibitors. Inflammation was produced by adding carrageenan into a newly formed air pouch and prostaglandins produced. While macrophages and neutrophils are present in the inflamed pouch, little 5-LOX products are formed. Cellular 5-LOX activation was obtained by adding calcium ionophore (A23187) into the pouch thus providing a novel model to evaluate the efficacy and selectivity of 5-LOX inhibitors. Also, we described modifications to the in vitro 5-LOX enzyme and cell assays. These assays included a newly developed fluorescence-based enzyme assay, a 5-LOX redox assay, an ex vivo human whole blood assay and an IgE-stimulated rat mast cell assay, all designed for maximal production of leukotrienes. Zileuton and CJ-13,610, a competitive, non-redox inhibitor of 5-LOX, were evaluated for their pharmacological properties using these assays. Although both compounds achieved dose-dependent inhibition of 5-LOX enzyme activity, CJ-13,610 was 3-4 fold more potent than zileuton in all-assays. Evaluation of 5-LOX metabolites-by LC/MS/MS and ELISA confirmed that both compounds selectively inhibited all products downstream of 5-hydroperoxy eicosatetraenoic acid (5-HPETE), including 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxoETE), without inhibition of 12-lipoxygenase (12-LOX), 15-lipoxygenase (15-LOX), or cyclooxygenase (COX) products. In the rat air pouch model, oral dosing of CJ-13,610 and zileuton resulted in selective inhibition 5-LOX activity from pouch exudate and ex vivo rat whole blood with similar potency to in vitro assay. These data show that the rat air pouch model is a reliable and useful tool for evaluating in vivo efficacy of 5-LOX inhibitors and may aid in the development of the next generation of 5-LOX inhibitors, such as the non-redox inhibitors similar to CJ-13,610.}, address = {Pfizer Global Research \& Development, Pfizer Inc., 700 N. Chesterfield Village Parkway, AA5G, St. Louis, MO 63017 United States.}, author = {Zweifel, Ben S S. and Hardy, Medora M M. and Anderson, Gary D D. and Dufield, Dawn R R. and Pufahl, Robert A A. and Masferrer, Jaime L L.}, citeulike-article-id = {2432058}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.ejphar.2008.01.021}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/18295198}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=18295198}, day = {5}, doi = {10.1016/j.ejphar.2008.01.021}, issn = {0014-2999}, journal = {Eur J Pharmacol}, keywords = {air-pouch, asthma, inflammation, leukotriene, rat}, month = {February}, posted-at = {2008-02-27 01:42:54}, priority = {2}, title = {A rat air pouch model for evaluating the efficacy and selectivity of 5-lipoxygenase inhibitors.}, url = {http://dx.doi.org/10.1016/j.ejphar.2008.01.021}, year = {2008} }

TY - JOUR ID - citeulike:2432058 L3 - citeulike-article-id:2432058 N2 - The 5-lipoxygenase (5-LOX) pathway has been associated with a variety of inflammatory diseases including asthma, atherosclerosis, rheumatoid arthritis, pain, cancer and liver fibrosis. Several classes of 5-LOX inhibitors have been identified, but only one drug, zileuton, a redox inhibitor of 5-LOX, has been approved for clinical use. To better evaluate the efficacy of 5-LOX inhibitors for pharmacological intervention, a rat model was modified to test the in vivo efficacy of 5-LOX inhibitors. Inflammation was produced by adding carrageenan into a newly formed air pouch and prostaglandins produced. While macrophages and neutrophils are present in the inflamed pouch, little 5-LOX products are formed. Cellular 5-LOX activation was obtained by adding calcium ionophore (A23187) into the pouch thus providing a novel model to evaluate the efficacy and selectivity of 5-LOX inhibitors. Also, we described modifications to the in vitro 5-LOX enzyme and cell assays. These assays included a newly developed fluorescence-based enzyme assay, a 5-LOX redox assay, an ex vivo human whole blood assay and an IgE-stimulated rat mast cell assay, all designed for maximal production of leukotrienes. Zileuton and CJ-13,610, a competitive, non-redox inhibitor of 5-LOX, were evaluated for their pharmacological properties using these assays. Although both compounds achieved dose-dependent inhibition of 5-LOX enzyme activity, CJ-13,610 was 3-4 fold more potent than zileuton in all-assays. Evaluation of 5-LOX metabolites-by LC/MS/MS and ELISA confirmed that both compounds selectively inhibited all products downstream of 5-hydroperoxy eicosatetraenoic acid (5-HPETE), including 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxoETE), without inhibition of 12-lipoxygenase (12-LOX), 15-lipoxygenase (15-LOX), or cyclooxygenase (COX) products. In the rat air pouch model, oral dosing of CJ-13,610 and zileuton resulted in selective inhibition 5-LOX activity from pouch exudate and ex vivo rat whole blood with similar potency to in vitro assay. These data show that the rat air pouch model is a reliable and useful tool for evaluating in vivo efficacy of 5-LOX inhibitors and may aid in the development of the next generation of 5-LOX inhibitors, such as the non-redox inhibitors similar to CJ-13,610. JF - Eur J Pharmacol SN - 0014-2999 AD - Pfizer Global Research & Development, Pfizer Inc., 700 N. Chesterfield Village Parkway, AA5G, St. Louis, MO 63017 United States. TI - A rat air pouch model for evaluating the efficacy and selectivity of 5-lipoxygenase inhibitors. KW - air-pouch KW - asthma KW - inflammation KW - leukotriene KW - rat AU - Zweifel, Ben S AU - Hardy, Medora M AU - Anderson, Gary D AU - Dufield, Dawn R AU - Pufahl, Robert A AU - Masferrer, Jaime L PY - 2008/02/05/ UR - http://dx.doi.org/10.1016/j.ejphar.2008.01.021 ER -