[Understanding differences between Rheum palmatum and R. franzenbachii from perspective of chemistry, efficacy and toxicity].

Rheum franzenbachii (called Tudahuang in local) has some similarities with R. palmatum (rhubarb) collected by "China Pharmacopoeia" and is often used as a substitute of rhubarb. Can Tudahuang simply replace rhubarb in the application or whether is there difference between Tudahuang and rhubarb, and what is the difference it is important to verify the difference and understand its proper application in the field of clinical practice. In this paper, we discussed the differences of the two herbs from the views of chemistry, efficacy and toxicity based on the author's previous research work as well as literatures, by using the major role of the rhubarb "diarrhea" as the basic point. The analysis result showed that the role of diarrhea Tudahuang was much weaker than that of rhubarb. The reason lies in the difference between the contents of combined anthraquinones component. While acute toxicity in mice of Tudahuang is stronger than that of rhubarb. Thus, Tudahuang should not simply replace rhubarb in practice.