Barbaloin administered orally was decomposed to aloe-emodin-9-anthrone and aloe-emodin in the rat large intestine. The metabolites were found to cause an obvious increase of water content in the large intestine. Aloe-emodin-9-anthrone inhibited rat colonic Na+, K+ adenosine triphosphatase in vitro and increased the paracellular permeability across the rat colonic mucosa in vivo. Therefore, it seemed that the increase in water content of the rat large intestine produced by aloe-emodin-9-anthrone was due to both inhibition of absorption and stimulation of secretion without stimulation of peristalsis. Charcoal transport was significantly accelerated at both 3.5 and 6.5 hours after the administration of barbaloin. At 6.5 hours, diarrhoea instead of normal feces was observed. Moreover, at one hour 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 ofperistalsis 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 (Ishii etal, 1994).
Was this article helpful?