Preventive effect of Dendrobium candidum Wall. ex Lindl. on activated carbon-induced constipation in mice.

The aim of this study was to investigate the effects of Dendrobium candidum Wall. ex Lindl. (D. candidum) on activated carbon-induced constipation in ICR mice. ICR mice were orally administered D. candidum for 9 days. Body weight, defecation status, gastrointestinal (GI) transit and defecation times, in addition to the levels of motilin (MTL), gastrin (Gas), endothelin (ET), somatostatin (SS), acetylcholinesterase (AChE), substance P (SP) and vasoactive intestinal peptide (VIP) in serum were used to evaluate the preventive effects of D. candidum on constipation. The laxative drug bisacodyl acted as a positive control. The time to the first defecation of a black stool for the normal, control, bisacodyl-treated (100 mg/kg), 200 and 400 mg/kg D. candidum-treated mice was 84, 202, 126, 161 and 142 min, respectively. Following the consumption of 200 and 400 mg/kg D. candidum or bisacodyl (100 mg/kg), the GI transit was reduced to 57.7, 74.6 and 90.2%, respectively, of the transit in normal mice. The serum levels of MTL, Gas, ET, AChE, SP and VIP were significantly increased and the serum levels of SS were reduced in the mice treated with D. candidum compared with those in the untreated control mice (P<0.05). These results demonstrate that D. candidum has preventive effects on constipation in mice, and a greater functional activity was observed when a higher concentration was administered.