Monitoring of radical scavenging activity of peroral administration of the Kampo medicine Sho-saiko-to in rats

The Kampo medicine Sho-saiko-to scavenged superoxide anion radicals (O-2(-)), hydroxyl radicals ( OH) and 1,1 -diphenyl-2-picrylhydrazyl (DPPH) radicals in a dose-dependent fashion. We attempted to investigate the transition of free radical scavenging activity in plasma after oral administration of Sho-saiko-to in rats. From the response-time profile, kinetic parameters including values for K-a (absorption rate constant), T-max (peak concentration time), T-1/2 (half life) and MRT (mean residence time) of radical scavenging activity in plasma could be calculated for the O-2(-), .OH and DPPH radicals. These parameters calculated from the dynamics of antioxidation are considered a very meaningful procedure to examine the effects of Sho-saiko-to.