Anti-hypertensive effect of Choto-san (Diao-Teng-San) in SHR : Role of Chotoko (Uncaria sp.) and gypsum
抄録
To clarify a role of Chotoko (Uncaria sp.) and gypsum in the anti-hypertensive effect of a Kampo prescription Choto-san (Diao-Teng-San), we investigated effects of Choto-san except Chotoko or gypsum, Chotoko alone and gyp-sum alone on the blood pressure and the heart rate in spontaneously hypertensive rats (SHR). Choto-san (0.5, 1.0 and 2.0 g/kg, p.o.) produced a dose-dependent hypotensive effect, but did not affect the heart rate in SHR. It affected neither blood pressure nor heart rate in normotensive Wistar-Kyoto (WKY) rats. When Chotoko was removed from the Choto-san prescription, the hypotensive effect of Choto-san disappeared. When gypsum was taken away from the prescription, the hypotensive effect was prominently reduced as compared with the parent prescription. The extract of Chotoko alone, which was boiled for 15 min, showed hypotensive action at a dose of 200 mg/kg, p.o., while the action disappeared after boiling for 60 min. The results corresponded with a traditional hypothesis that anti-hypertensive components in Choto-san may be destroyed after boiling for over 60 min. A single administration of the extract of gypsum alone at a dose of 1 g/kg, p.o. produced a significant hypotensive effect. These results suggest that both Chotoko and gypsum exerts an important role in the anti-hypertensive effect of Choto-san.