Renierol from marine sponge Haliclona.SP.: a natural inhibitor of xanthine oxidase with hypouricemic effects.

ABSTRACT

The purpose of this study was to evaluate the inhibitory effect of renierol, extracted from marine sponge Halicdona.SP., on xanthine oxidase (XO) and its hypouricemic effect in vivo. Renierol and a positive control, allopurinol, were tested for their effects on XO activity by measuring the formation of uric acid and superoxide radical from xanthine. Renierol inhibited XO in a concentration-dependent and competitive manner. IC(50) value was 1.85 microg.ml(-1) through the measuring of uric acid and was 1.36 microg.ml(- 1) through the measuring of superoxide radical. Renierol was found to have an in vivo hypouricemic activity against potassium oxonate-induced hyperuricaemia in mice. After oral administration of renierol at doses of 10, 20 and 30 mg.kg(- 1), there was a significant decrease in the serum urate level (4.08 +/- 0.09 mg.dl(- 1), P < 0.01), (3.47 +/- 0.11 mg.dl(- 1), P < 0.01) and (3.12 +/- 0.08 mg.dl(- 1), P < 0.01), when compared to the hyperuricaemic control (6.74 +/- 0.23 mg.dl(- 1)). Renierol was a potent XO inhibitor with hypouricemic activity in mice.