Different effects on the tonus of colon and ileum isolated from mouse by resin glycoside (pharbitin) of Pharbitidis Semen

Pharbitidis Semen (the seeds of Pharbitis nil), traditionally used as a purgative in Japan, China and Korea, contains a resin glycoside fraction named pharbitin, which is known as a purgative ingredient. Due to the complex nature of pharbitin, little is known about either the action on intestinal tension caused by resin glycoside itself or by its components. In this study, we investigated the effects of pharbitin, the glycosidic acid fraction (pharbitic acid) and the aglycone fraction (phar-genin) generated from pharbitin on peristalsis of colon and ileum isolated from mice with the Magnus method. We demonstrated that pharbitin (3-30 μg/mL) concentration-dependently increased tonus of mice colon via acetylcholine receptors, its components phar-genin (1.27-12.7 μg/mL) and pharbitic acid (10-1000 μg/mL) also had the increment on colon tonus. On the other hand, ileum tension decreased in the presence of pharbitin. The effects of resin glycoside of Pharbitidis Semen on colon tonus are different with those on ileum tonus isolated from mice. In the next step it is necessary to investigate details of its pharmacological mechanism.