Study on the Accumulation Pattern of Medicinal Substances in Polygala tenuifolia Based on Content Determination and Fingerprint Atlas
Polygalae Radix is the dried root of Polygala tenuifolia Willd. or Polygala sibirica L. in the family Polygalaceae, harvested in spring and autumn. The main active ingredients of Yuanzhi are triterpenoid saponins, oligosaccharides, ketones, as well as alkaloids, phenylpropanoids, organic acids, and other components. Yuanzhi ketone substances have antioxidant and antibacterial effects; 3,6 ‘- disuccinosyl sucrose has anticoagulant effects; Yuanzhi saponins have neuroprotective effects and have a certain effect on the treatment of Alzheimer’s disease. According to the 2020 edition of the Pharmacopoeia of the People’s Republic of China, the content of Polygalacanthone III (PX III) in the medicinal herb and its decoction pieces shall not be less than 0.15%, 3,6 ‘- sinapylsucrose (DISS) shall not be less than 0.5%, and tenuifolin (TEN) shall not be less than 2.0%. The existing research on the evaluation of medicinal materials is based on the content of chemical components, and there is relatively little research on the differentiation of factors such as different origins, sources, cultivated or wild, different medicinal parts, and growth years. It cannot comprehensively evaluate the value and efficacy of medicinal materials, and cannot comprehensively evaluate the advantages and disadvantages of medicinal materials from different germplasm resources, planting areas, and planting and harvesting times of Yuanzhi.
The accumulation law of medicinal substances is closely related to the growth year and harvesting time of medicinal materials, which have a direct impact on the quality and efficacy of the medicinal materials themselves. Therefore, choosing the appropriate harvesting time is the key to ensuring the effectiveness of medicinal materials. The study of the accumulation law of medicinal substances can provide a reference for their planting and harvesting, and can ensure the content of medicinal substances, thereby ensuring their efficacy. The growth and planting year of Yuanzhi is mainly 3 years old, usually harvested in October after planting for two years or in March or April of the following year. The Pharmacopoeia of the People’s Republic of China stipulates that Yuanzhi should be harvested in spring and autumn. Although the harvesting period is specified, there is no requirement for the growth period. Yuanzhi has scarce wild resources and is a nationally protected third level wild plant. Currently, most of the circulating products are cultivated Yuanzhi. Shanxi is the real estate area of Yuanzhi, and 80% of the Yuanzhi products sold on the market are produced in Shanxi. The cultivation resources are mainly concentrated in Xinjiang, Wenxi, Hongdong and other places in Shanxi Province.
This study uses quantitative and fingerprint methods to comprehensively investigate the relationship between different origins, growth years, and harvesting times of Polygala tenuifolia and the cumulative patterns of its length, diameter, water content, extract, and content determination. The aim is to provide scientific basis for the selection, cultivation, and harvesting of Polygala tenuifolia medicinal materials.

 

The content and accumulation pattern of active ingredients in medicinal plants are influenced by various factors such as source, planting, harvesting, and environment. The extension of the growth time of medicinal materials not only has a direct impact on their characteristics such as length and diameter, but also has a significant impact on the content of active ingredients, which in turn affects their medicinal efficacy. The optimal harvesting period for traditional Chinese medicinal materials should include the dual concepts of harvesting time and harvesting duration. Harvesting should be carried out during the period when the active ingredient content is high and the appearance is good, in order to obtain high-quality medicinal materials and achieve better medicinal effects. In addition to measuring the characteristics of medicinal materials, this study used hot soaking and HPLC to investigate the accumulation of active substances in 12 batches of Yuanzhi medicinal materials from the same source, different years, origins, and harvesting times, from various aspects such as the content of extracts, PX III, DISS, and TEN, as well as the similarity and peak area of fingerprint spectra.
The alcohol extract content of 12 batches of medicinal materials is all greater than 30%, and the DISS content is all greater than 0.50%; Using PX III as the indicator, only the content of S-1-4 and S-1-5 reached 0.15%; Using TEN as the indicator, only S-1-1, S-2-2, and S-2-5 have a content of 2.0%. The literature shows that the qualification rate of HPLC determination of PX Ⅲ in Yuanzhi medicinal materials is around 50%~80%; The range of TEN content is 1.4% to 4.4%, which is similar to the results of this study. The reason for the large variation range in content determination may be due to the existence of two molecular configurations of PX III and low sensitivity of ELSD detector. The diversity of chemical components in Yuanzhi medicinal materials requires consideration of the rationality and accuracy of using the content of these three chemical components as indicators to evaluate the quality of Yuanzhi.
This study found that the water content, extract content, and total content of three indicator components in Yuanzhi produced from Xinjiang were higher than those produced from Fenyang; The total content of extracts and components from medicinal herbs harvested in spring in both regions is higher than that harvested in autumn. Shanxi is the authentic production area of Yuanzhi, and the production areas are mostly distributed in the southwest of the mountains. Compared with Fenyang, Xinjiang is located in the south. This study shows that Xinjiang is more suitable for the planting and cultivation of Yuanzhi. The content of extracts and total components in the two regions of Polygala tenuifolia is related to the harvesting season, with higher content in spring. This study suggests that Polygala tenuifolia harvested in spring is more suitable for the same growth year.
The accumulation pattern of medicinal substances in medicinal herbs is closely related to their variety, place of origin, and harvesting time. The determination of harvesting time for medicinal herbs also needs to consider the influence of variety, place of origin, and different medicinal parts, and may result in different growth periods and harvesting times due to different therapeutic purposes. Further exploration can be conducted to determine whether the harvesting time can be flexibly, reasonably, and selectively arranged based on the different pharmacological substances used to treat diseases. Due to the limitations of selecting sample batches for this study, the limited number of samples in different batches, and the rationality of the selected measured components, further research is needed to determine whether the results of this experimental study are representative and comprehensive. In addition, it is necessary to conduct in-depth research on whether other planting areas and different sources of Polygala tenuifolia across the country have the same accumulation pattern, in order to provide more reliable references for the planting and harvesting of Polygala tenuifolia.