Studies of aloe. IV. Mechanism of cathartic effect. (3)

Charcoal transport, as an indicator of the degree of peristalsis, and water content in the large intestine after the intracaecal administration of barbaloin, were measured simultaneously in the same rat. Charcoal transport was significantly accelerated at both 3.5 and 6.5 h after the administration of barbaloin. At 6.5 h, diarrhea instead of normal faeces was observed. Moreover, at 1 h before the acceleration of charcoal transport, a marked increase in the relative water content of the large intestine was observed. It appears that the increase in water content of the large intestine induced by barbaloin precedes the stimulation of peristalsis, attended by diarrhea. Therefore, it is suggested that the increase in water content is a more important factor than the stimulation of peristalsis in the diarrhea induced by barbaloin.