从化学、药效和毒性角度比较认识正品大黄与土大黄

土大黄与药典收载的正品大黄具有某些功效的相似性,常常被用作大黄替代品应用。究竟土大黄与正品大黄能否简单的替换使用,或者说两者之间有无差异,差异在何处?对此进行研究,对于正确认识土大黄,以及临床与市场上的正确应用等都具有重要意义。该文在作者己有的工作基础上,结合相关文献报道,以大黄的主要功效"泻下"为基本点,从化学、药效及其毒性等方面进行了探讨。分析结果表明,华北大黄(土大黄)的泻下作用弱于正品大黄,其原因在于两者间结合型蒽醌类成分的含量差异,同时华北大黄的小鼠急性毒性也强于正品大黄,因此,华北大黄不宜简单的替代正品大黄使用。

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.