Lignan contents of Schisandra chinensis (Turcz.) Baill. from different origins—A new model for evaluating the content of prominent components of Chinese herbs

As a traditional Chinese herbal medicine, Schisandra chinensis exhibits various effects such as liver protection, blood sugar regulation, blood lipid regulation, immune function regulation, antidepressant activity, etc. However, because of its intricate composition, diverse origins, and medicinal effects depending on complex compound groups, there are differences in the lignan composition of Schisandra chinensis from different origins. Therefore, it is currently difficult to evaluate the quality of medicinal materials from plants of different origins using a single qualitative quality control index. This paper aims to investigate the potential relationship between the lignan components of Schisandra chinensis from different origins and to establish stable assessment indices for determining the lignan content of Schisandra chinensis from multiple perspectives. In this study, we collected Schisandra chinensis samples of seven major origins in China, and randomly sampled 6-9 batches of each origin for a total of 60 batches. The lignan content was determined by HPLC, and its distribution law of the ratio of each lignan component of S. chinensis to Schisandrol A content was analyzed. Combining network pharmacology and differential analysis between samples, the stable and effective substances used as quality markers were determined. There were some correlations among the lignan contents of Schisandra chinensis, some correlations between schisandrin A and other lignans of Schisandra chinensis could be determined. The ratio of each component to the indicator component schisandrol A was evenly distributed and reflected the lignan content of Schisandra chinensis to some extent. Four substances (schisandrol A, schisandrol B, schisantherin A, and schisandrin C) were determined by network pharmacology combined with the analysis results of HCA, PCA and PLS-DA to further optimize the model. They displayed a strong connection with the core target, a large contribution rate to the principal components, and a stable content in each batch of samples, suggesting that these components may be the main active substances of Schisandra chinensis lignans. Therefore, they could be used as main indicators evaluating the advantages and disadvantages of Schisandra chinensis by examining the consistency of component proportions. This method can intuitively evaluate the content of main lignans in Schisandra chinensis. This quality assessment model is an exploration of the multi-component comprehensive evaluation system of Schisandra chinensis, providing a new concept for the quality evaluation system of Chinese herbal medicines.