HIGH-MOLECULAR-WEIGHT HYALURONAN - A VALUABLE TOOL IN TESTING THE ANTIOXIDATIVE ACTIVITY OF AMPHIPHILIC DRUGS STOBADINE AND VINPOCETINE

The antioxidative activity of stobadine and vinpocetine was studied in vitro by measuring their inhibition effect on the depolymerization of the high-molecular-weight hyaluronan by hydroxyl radicals. The radica ls were generated by the Cu2+-H2O2 system. Hyaluronan depolymerization was monitored by means of size exclusion chromatography. The antioxid ative activity of stobadine and vinpocetine was compared to that of D- mannitol. A 50% inhibition of hyaluronan depolymerization was reached at stobadine and vinpocetine concentrations of 1.7 x 10(-6) and 3.0 x 10(-7) mol 1(-1), respectively, while a D-mannitol level of 2.6 x 10(- 3) mol 1(-1) was needed to achieve the same inhibitory effect. (C) 199 7 Elsevier Science B.V.