The Yin-Yang Property of Chinese Medicinal Herbs Relates to Chemical Composition but Not Anti-Oxidative Activity: An Illustration Using Spleen-Meridian Herbs.

Yun Huang,Tina Ting Xia Dong,Huaiyou Wang,Xiang Peng Kong,Ping Yao,Yicun Chen,Karl Wah Keung Tsim,Long Wang,Ka Wing Leung

doi:10.3389/fphar.2018.01304

Abstract

“Yin-Yang” and “Five Elements” theories are the basis theories of Traditional Chinese Medicine (TCM). To probe and clarify the theoretical basis of these ancient Chinese wisdoms, extensive efforts have been taken, however, without a full success. In the classification of TCM herbs, hot, cold and neutral herbs are believed to possess distinct profile of chemical compositions of which the compounds should have different polarity and mass: this view provides a new perspective for further illustration. To understand the chemical properties of TCMs in the classification of “Yin-Yang” and “Five Elements,” 15 commonly used herbs attributed to spleen-meridian were selected for analyses. Chemically standardized water extracts, 50% ethanol extracts and 90% ethanol extracts were prepared and subjected to different analytic measurements. Principle component analysis (PCA) of full spectrum of HPLC, NMR and LC-MS of the extracts were established. The results revealed that the LC-MS profile showed a strong correlation with the “Yin-Yang” classification criterion. The Yang-stimulating herbs generally contain more compounds with lower molecular weight and less polar property. Additionally, a comprehensive anti-oxidative profiles of selected herbs were developed, and the results showed that its correlation with cold and hot properties of TCM, however, was rather low. Taken together, the “Yin-Yang” nature of TCM is closely related to the physical properties of the ingredients, such as polarity and molecular mass; while such classification has little correlation with anti-oxidative property. Therefore, the present results provide a new direction in probing the basic principle of TCM classification.

Highlights

In the theoretical basis of Traditional Chinese Medicine (TCM) clinical application, “Yin-Yang” and “Five Elements” theories could further differentiate into secondary classification principles, e.g., four natures and five flavors, meridian tropism, floating and sinking (Li et al, 2008; Fu et al, 2009, 2015; Mohd et al, 2013; Qiu, 2015)
The water extracts and ethanol extracts of individual herbs were prepared with the consideration of their common usage and historical preparation of a herbal decoction in TCM
Similar to HPLC fingerprint, the NMR profile showed close similarity between herbs extracted with the same solvents, and generally the 90% ethanol extracts showed higher content of chemical composition, as compared with that of other extracts (Figure 3)

Summary

Introduction

In the theoretical basis of TCM clinical application, “Yin-Yang” and “Five Elements” theories could further differentiate into secondary classification principles, e.g., four natures and five flavors, meridian tropism, floating and sinking (Li et al, 2008; Fu et al, 2009, 2015; Mohd et al, 2013; Qiu, 2015). The works on chemical properties of TCMs has made a significant progress, and new ideas have been proposed, e.g., molecular drug hypothesis (Fu et al, 2017b), biodynamics (Yang et al, 2017), genetic hypothesis (Rezapour-Firouzi, 2017), transient receptor potential channel hypothesis (Bishnoi et al, 2018) Many of these newly proposed methods have been adopted and improved, including micro-calorimetry (Gao et al, 2014), mathematical modeling (Ramirez-Rodrigues et al, 2011), biophoton detection (Han et al, 2011; Zhao and Han, 2013). These studies are still lacking a co-relationship of the current TCM theory with the chemical composition of different classes of herbs

Methods

Results

Conclusion