Ursodeoxycholic acid and superoxide anion.

AIM: To investigate the ability of ursodeoxycholic acid (UDCA) to scavenge superoxide anion (O(2)(-)). METHODS: We assessed the ability of UDCA to scavenge (O(2)(-)) generated by xanthine-xanthine oxidase (X-XO) in a cell-free system and its effect on the rate of O(2)(-)-induced ascorbic acid (AA) oxidation in hepatic post-mitochondrial supernatants. RESULTS: UDCA at a concentration as high as 1 mmol/L did not impair the ability of the X-XO system to generate O(2)(-), but could scavenge O(2)(-) at concentrations of 0.5 and 1 mmol/L, and decrease the rate of AA oxidation at a concentration of 100 micromol/L. CONCLUSION: UDCA can scavenge O(2)(-), an action that may be beneficial to patients with primary biliary cirrhosis.