Aim: 

Caffeic acid phenethyl ester (CAPE) exerts pharmacological actions (e.g. anti-inflammatory, chemopreventive) which are relevant for potential clinical application in the digestive tract. In the present study, we investigated the effect of this phenolic compound on intestinal motility (both in vivo and in vitro) and on diarrhoea.

Methods: 

Motility in vivo was measured by evaluating the distance travelled by an orally-given marker along the small intestine (in both normal and inflamed gut) or by measuring the expulsion of a glass bead inserted into the distal colon. Diarrhoea was induced by croton oil (CO). Motility in vitro was studied by evaluating the effect of CAPE on the spontaneous contractions of the isolated ileum.

Results: 

In vivo, CAPE (10–100 mg/kg) reduced motility in the upper gastrointestinal tract [both in physiological (transit %: control 44.7 3; CAPE 10 mg/kg 30.5 3.4; CAPE 30 mg/kg 22.43 2.7; CAPE 100 mg/kg 17.3 1.2) and in pathophysiological states (transit %: control 47 3.0; CO 62.3 2.8; CO+CAPE 10 mg/kg 58.2 4.7; CO+CAPE 30 mg/kg 26.5 2.3; CO+CAPE 100 mg/kg 24.7 2.2) and in the colon (mean expulsion time: control 6.4 0.5; CAPE 10 mg/kg 8.8 0.7; CAPE 30 mg/kg 10.5 1.9; CAPE 100 mg/kg 18.9 0.9l)]. CAPE also attenuated croton-oil induced diarrhoea. In vitro, CAPE (3 mM–100 mM) reduced (in a tetrodotoxin-insensitive manner) ileal spontaneous contractions and this effect was reduced by the L-type Ca²⁺ channel blocker nifedipine.

Conclusions: 

CAPE reduces diarrhoea and intestinal motility in vivo. In vitro, studies suggest a direct inhibitory effect on intestinal smooth muscle, possibly with a mechanism involving L-type Ca²⁺ channels. CAPE could be considered for clinical evaluation in diseases characterized by increased contractility and transit, as the inflamed gut.