Ethnopharmacologic study of Chinese rhubarb.

This paper deals with an interdisciplinary study covering historic, botanical, phytochemical, pharmacological and clinical aspects of rhubarb and related species, to lay stress on the correlation between plant phylogeny, chemical constituents and purgative activity. It was found that the official rhubarbs were exclusively restricted in the Sect. Palmata, e.g. Rheum palmatum, R. palmatum var. tanguticum, R. officinale; the following criteria may serve as their standard, viz., the presence of sennoside derivatives and rhein, the occurrence of the reduced form of rhein and aloe-emodin, the leaves with any kind of palmate incision. Comprehensive multivariate analyses showed that there is a very close relationship between the leaf incision, existence of sennosides or rhein and purgative activity.