Inhibitory effect of caffeic acid phenethyl ester, a plant-derived polyphenolic compound, on rat intestinal contractility

Caffeic acid phenethyl ester (CAPE) exerts pharmacological actions (e.g. anti-inflammatory, chemopreventive) which are relevant for potential clinical application in the digestive tract. However, no study has been published on its possible effects on intestinal motility, to date. In the present study, we investigated the effect of this plant-derived polyphenolic compound on the spontaneous contractions of the rat isolated ileum. CAPE reduced (in a tetrodotoxin-insensitive manner) spontaneous ileal contractions and this effect was reduced by the l-type Ca2+ channel blocker nifedipine and the chelant of calcium ethylenediaminetetraacetic acid. However, the effect of CAPE was not modified by a number of inhibitors/antagonists such as of phentolamine plus propranolol, atropine, tetrodotoxin, cyclopiazonic acid, ω-conotoxin, apamin, NG-nitro-l-arginine methyl ester, 3-isobutyl-1-methylxanthine, 9-(tetrahydro-2-furanyl)-9H-purin-6-amine, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one or a combination of SR 140333, SR48968 and SR142801. In conclusion our study shows that (i) CAPE relaxed myogenic contractions of rat ileum and that (ii) this effect occurs, at least in part, throughout a mechanism involving l-type Ca2+ channels.