Low-dose ursodeoxycholic acid prolongs cholesterol nucleation time in gallbladder bile of patients with cholesterol gallstones

The high rate of stone recurrence represents a drawback of
non-surgical therapy of cholesterol gallstone disease. Although
most studies report that long-term bile acid treatment does not
have protective effects, preliminary results suggest that low-dose
ursodeoxycholic acid decreases the rate of gallstone recurrence in
a subgroup of younger patients. To clarify the underlying mechanism
we investigated whether low-dose ursodeoxycholic acid treatment
influences biliary cholesterol saturation and/or nucleation time of
cholesterol. Ten patients with cholesterol gallstones and
functioning gallbladder received 250 mg ursodeoxycholic acid/day at
bedtime 6–10 days prior to cholecystectomy. Eleven patients with
cholesterol gallstones without treatment served as controls.
Cholesterol crystals were present in the gallbladder bile of 7 out
of the 10 patients receiving ursodeoxycholic acid and in all
control biles. Ursodeoxycholic acid treatment significantly (P <
0.02) decreased the cholesterol saturation index (mean ± S.E.: 0.94
± 0.05 vs. 1.43 ± 0.18) and led to an approximately 5-fold
prolongation (P < 0.005) of the cholesterol nucleation time
(mean ± S.E.: 12.0 ± 2,4 vs. 2.3 ± 0.7 days). We conclude that
lowdose ursodeoxycholic acid might be effective in the prevention
of post-dissolution gallstone recurrence by both decreasing
cholesterol saturation and prolonging cholesterol nucieation time