A Combined Quality Evaluation Method That Integrated Chemical Constituents, Appearance Traits and Origins of Raw Rehmanniae Radix Pieces

Abstract

Background The quality control of traditional Chinese medicine (TCM) is a challenge for internationalization of TCM. Modern quality evaluation methods ignore origins and appearance traits, and traditional quality evaluation methods lack quantitative analysis. Therefore, an integrated quality evaluation method is urgent in need. Raw Rehmanniae Radix (RRR) was a widely used TCM. Its quality has caught much attention, and the existing quality evaluation methods have certain limitations. The aim of this study was to establish a comprehensive and practical method for the quality evaluation and control of RRR pieces based on its chemical components, appearance traits and origins.Methods 33 batches of RRR pieces were collected from 6 provinces, high performance liquid chromatography (HPLC) was applied to determine 5 constituents including catalpol, rehmannioside A, rehmannioside D, leonuride and verbascoside in RRR pieces. The appearance traits were qualitatively observed. Furthermore, correlation analysis, principal components analysis (PCA), cluster analysis and t-test were performed to discriminate and evaluate different quality of RRR pieces. Results 33 batches of RRR pieces could be divided into three categories, the samples of Henan province were in a group, the samples from Shandong province and Shanxi province were classified in a group, and the samples from other provinces were divided in a group. Furthermore, the constituents and appearance traits of RRR pieces were significantly different in diverse origins. Conclusions The combined method of chemical components, appearance traits and origins could classify and distinguish different quality of RRR pieces, which could provide a basic reference to quality control of TCM.