Intraluminal administration of zingerol, a non-pungent analogue of zingerone, inhibits colonic motility in rats

Zingerone, a pungent component of ginger, may exert beneficial therapeutic effects on hypermotility-induced diarrhea because it has the ability to inhibit contractions of colonic smooth muscles. However, the pungency is undesirable for possible therapeutic use. The purpose of this study was to examine effects of zingerol, a non-pungent analogue of zingerone, in rats. Colonic motility in vivo was evaluated by measuring intraluminal pressure changes and expelled fluid volume from the colon in anesthetized rats. Mechanical contractile activities of isolated colonic segments were also recorded. Intracolonic administration of zingerol attenuated colonic motility in vivo without affecting blood pressure and heart rate in a manner similar to that of zingerone. Zingerol also inhibited spontaneous contractile movements in isolated colonic segments, suggesting that zingerol directly acts on the colon. Zingerol had no effect on jejunal motility, although zingerone showed an inhibitory effect to the jejunum. These findings suggest that zingerol can inhibit colonic motility without adverse effects on small intestinal motility and the cardiovascular system. The non-pungent property of zingerol will be useful as an oral or suppository medicine for treating diarrhea and other gastrointestinal disorders.