ELECTROCHEMICAL METHOD FOR ESTIMATING THE ANTIOXIDATIVE EFFECTS OF METHANOL EXTRACTS OF CRUDE DRUGS

The antioxidative effects of methanol extracts of crude drugs were est imated by an electrochemical method because there are many electrochem ically-active substances in natural antioxidants. Twelve kinds of crud e drugs, which had been reported to exhibit strong activity in an anti oxidative test based on the air oxidation of linoleic acid, were studi ed. The oxidative capacity calculated from voltammograms of their meth anol extracts were compared and examined together with data on their r adical scavenging effects. The results showed that the electrochemical behavior in most cases correlated with the radical scavenging effect. Crude drugs which had clear oxidative peaks below + 1.2 V and a large oxidative capacity were suggested to have strong radical scavenging e ffects. It was clear that substances oxidized at lower potentials had stronger radical scavenging effects than those oxidized at higher pote ntials. Therefore, this electrochemical method can be considered as a rapid and simple method for estimating the antioxidative effects as a radical scavenger.