Does ursodeoxycholic acid change the proliferation of the colorectal mucosa? A randomized, placebo-controlled study

Background: In animal models ursodeoxycholic acid (UDCA) showed a
chemoprotective effect against colon cancer. To explain this, a
reduced proliferation of the colorectal mucosal proliferation was
suggested. We, therefore, examined the influence of UDCA on the
proliferation of normal colorectal mucosa in humans. Methods:
Following endoscopic polypectomy, 20 patients with colorectal
adenomas were randomized to receive either UDCA (750 mg/day, n =
10, group A) or placebo (n = 10, group B) for 6 months in a
double-blinded way. Colorectal biopsies were sampled before and at
the end of the medication by total colonoscopy. Colorectal mucosal
proliferation was measured by FACScan analysis of propidium iodine
labeling. Serum was sampled, and serum bile acids were analyzed by
gas chromatography. Results: The proliferation rates at the end of
the study were similar in both groups (median 15.4%; range
12.0-20.9 in group A; median 16.0%, 14.0-20.2 in group B, p =
0.41). Serum lithocholic acid levels at the end of the study were
significantly higher in group A (1.3 mumol/l, 0.9-1.8) than in
group B (0.7 mumol/l, 0-1.7, p < 0.02), whereas serum
deoxycholic acid levels were similar in both groups. Conclusions:
In this study, UDCA treatment for 6 months does not seem to induce
changes in the proliferative behavior of the colorectal mucosa in
patients with adenomas. It seems likely that a putative
chemopreventive effect of UDCA in humans is not exerted by a
reduction of the colorectal proliferation. Copyright (C) 2003 S.
Karger AG, Basel.