Toru Egashira (1), Fusako Takayama (1), Yasumitsu Yamanaka (1) and Yasuhiro
(1) Department of Pharmacology, Oita Medical University, 1 - 1, Idaigaoka, Hasama-machi, Oita 879 - 5593, Japan
(2) Kampo and Pharmacognosy Laboratories, Tsumura & Co., Ami-machi, Inashiki-gun, Ibaragi 300 - 1192, Japan
Abstract: The Kampo medicine Sho-saiko-to scavenged superoxide anion radicals (O2-), hydroxyl radicals (EOH) 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 Ka (absorption rate constant), Tmax (peak concentration time), T1/2 (half life) and MRT (mean residence time) of radical scavenging activity in plasma could be calculated for the O2-, EOH 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.
Keywords: Sho-saiko-to (Kampo medicine), Radical scavenger, Pharmacodynamics