Studies of Rhei Rhizoma (Da-huang; Daio). (I). A Herbological Study on its Medicinal Effects and Medicinal Parts / 日本東洋医学雑誌

ABSTRACT

Although the crude drug Rhei Rhizoma (Chinese Da-huang; Japanese Daio) is now commonly employed as a purgative, some question remains as to whether it was originally used as a depurative (purifying agent; specifically an agent for expelling Stagnated Blood) or purgative in ancient times. There is also some confusion as to the medicinal part of the crude drug being sold on the market. This herbological study was carried out in order to clarify these issues.<br>The results showed that Rhei Rhizoma was originally used mainly as an agent to expel Stagnated Blood, although it was also used for its purgative and other properties. Until the Qing dynasty, the rhizome of the large Rheum species, including R. palmatum, was known as the best quality Da-huang. The recent use of the root is thought to be due to recognition of the purgative properties of Da-huang.<br>Da-huang has many medicinal properties in addition to its usefulness as a purgative, and there is a need for further study of these properties as well as the differences between the pharmacological actions of the rhizome and those of the root.