How Many Traditional Chinese Medicine Components Have Been Recognized by Modern Western Medicine? A Chemoinformatic Analysis and Implications for Finding Multicomponent Drugs

Traditional Chinese medicine (TCM), featured in its combinatorial use of herbs (sometimes animals and minerals are also involved), has been developed in China for more than 4 000 years. Although TCM attracts more and more attention from medicinal practice throughout the world and is considered a promising source of new drugs, [1–7] it is still outside mainstream medicine, because of the conceptual differences between TCM therapy and modern medication. However, it should be pointed out that historically Western medicine also depended on natural products (for over 3 000 years) and synthetic modern drugs only began to blossom approximately 100 years ago. [8, 9] In addition, it is estimated that ~ 50 % of currently used modern Western drugs are derived from natural products. [9–12] Considering the fact that the plant distribution patterns in China and Western countries are rather similar, it is reasonable to infer that there exist certain similarities between TCM components and modern Western drugs and some TCM components may have been recognized by modern Western medicine, although by and large both medical systems evolved independently. To verify this speculation, we employed chemoinformatic methods to make a global structural comparison between the two kinds of drugs. Structurally similar agents in TCM and modern Western medicine In the present analysis, traditional Chinese medicine database (TCMD), [13] which records 10 458 components extracted from 4 636 TCMs (including herbs, animals, and minerals) and the comprehensive medicinal chemistry (CMC) database, [14] which contains 8 659 approved modern drugs (of which 7 988 molecules are represented in Mol2 format), were used as data sources of TCM components and modern Western drugs, respectively. The molecular similarity comparison of TCMD and CMC database was performed by using atom environment descriptors (MOLPRINT 2D). [15] As a result, 908 TCMD–CMC agent pairs were found to be structurally similar (with similarity > 85 %) and 327 agents were revealed as common members of both databases, which indicates that a certain part of TCM components have been recognized by modern Western medicine. As the structurally identical agents are of special interest to our study, they are listed in Table S1 and are analyzed in detail (see below).