Novel compounds that interact with both leukotriene B4 receptors and vanilloid TRPV1 receptors.

The aim of this study was to investigate the interaction of a series of novel compounds with leukotriene B(4) receptors (BLT) and vanilloid receptor (TRPV1). First, we characterized leukotriene B(4) (LTB(4)) ethanolamide. In guinea pig isolated lung parenchyma, LTB(4) ethanolamide antagonized the contractile action of LTB(4) with an apparent K(B) value of 7.28 nM. Using a Boyden chamber assay, we demonstrated that this compound stimulated human neutrophil migration in a similar manner to LTB(4) but with lower efficacy. In rat TRPV1 (rTRPV1)-expressing Chinese hamster ovary (CHO) cells and dorsal root ganglion (DRG) neurons, LTB(4) and LTB(4) ethanolamide acted as low-efficacy agonists, increasing intracellular calcium concentration ([Ca(2+)](i)) in a capsazepine-sensitive manner. These results prompted us to hypothesize that a molecule may possess pharmacophores such that it is capable of dual antagonism of BLT and TRPV1 receptors. Two novel compounds, N-[2-fluoro-4-[3-(11 hydroxyheptadec-8-enyl)-thioureiomethyl]-phenyl]-methanesulfonamide (O-3367) and N-[4-[3-(11 hydroxyheptadec-8-enyl)-thioureio-methyl]-phenyl]-methanesulfonamide (O-3383), were synthesized. In human neutrophils, both compounds acted as antagonists, significantly attenuating the BLT receptor-mediated ability of LTB(4) to induce migration, with pIC(50) values of 7.22 +/- 0.17 and 5.95 +/- 0.16, respectively. In rTRPV1-expressing CHO cells, they caused a significant rightward shift in the log concentration-response curve for the TRPV1 receptor agonist capsaicin (3-methoxy-4-hydroxy)benzyl-8-methyl-6-nonenamide). In DRG neurons O-3367 significantly attenuated the capsaicin-induced increases in [Ca(2+)](i) with a pIC(50) value of 5.94 +/- 0.004. O-3367 and O-3383 represent novel structural templates for generating compounds possessing dual antagonism at BLT and TRPV1 receptors. In view of the crucial role of both TRPV1 and BLT receptors in the pathophysiology of inflammatory conditions, such compounds may betoken a novel class of highly effective therapeutics.

Recovery of the Decorin-Enriched Fraction, Extract (D), From Human Skin: An Accelerated Protocol.

The original extraction procedure of Engel and Catchpole [1] has often been used to recover decorin-enriched material from the skin. This material has a strong inhibitory effect on fibroblast proliferation, and clearly suppresses it in skin except after the first 5-6 days of wounding when new scaffold material is required. The aim of our present study has been to find and evaluate the product of a faster recovery method, and to check its consistency as a more reliable means of regularly obtaining sufficient material for topical application in wounds that might become hypertrophic. Modifications of the original Toole and Lowther [2] extraction procedure have been carefully evaluated in an attempt to cut preparation time without compromising biological activity of the inhibitory extract. We have devised a faster recovery procedure without compromising biological activity, even if initial recovery has been somewhat reduced. The latter problem could be offset by repeated cycles of the final extraction step. The main inhibitory activity is shown to be within the decorin-enriched "extract D," as the core protein and DSPG II. Adjustment of the extract towards neutrality after dialysis against water keeps most of the extracted protein in solution and yielded a decorin-enriched preparation that had a specific activity equivalent to that of the old method. It also yielded a fraction that was readily lyophilised to give a small amount of material that could be stored indefinitely without loss of activity and readily redissolved in aqueous solution. A reliable and relatively quick method is presented for the production, from human skin, of a decorin-enriched preparation that has strong fibroblast inhibitory action. The value of the procedure is that it is inexpensive and can produce the quantities that might be used topically in reducing hypertrophic scarring of wounds.