ABSTRACT
Oketsu is a characteristic pathophysiology in Kampo and traditional East Asian medicine that includes multiple aspects of hemodynamic disorder. Anti-oketsu drugs or the Kampo formulation used for oketsu show significant clinical effects on various disorders; however, their underlying mechanisms still remain unclear. We aimed to clarify the characteristics of the pharmacological effects of anti-oketsu drugs on the microcirculation using a microscopic live imaging technique. Three Kampo formulations, namely tokakujokito, keishibukuryogan, and tokishakuyakusan were orally administrated to C57BL/6 mice at a dose of 300 mg/kg diluted in distilled water. Live imaging was performed on the subcutaneous vessels of the mice, including the arteries (diameter > 50 μm), arterioles (diameter 10-50 μm) and capillaries (diameter < 10 μm). Tokakujokito widely increased erythrocyte flow velocity and blood flow volume from arteries to capillaries within 60 min of administration. The effects of keishibukuryogan on the vasodilation of the arterioles were remarkable, and continued up to 120 min after administration. The pharmacological target of tokishakuyakusan was the capillaries, increasing their erythrocyte velocity and blood flow volume;its effect was more slowly expressed than those of the other formulations. Our results clearly demonstrate the sequential and special effects of anti-oketsu drugs on hemodynamics. These differences may provide pharmacological information on the clinical usage of traditional Kampo formulations.