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.