Abstract:

To investigate the characteristics of glycosides and their anti-tumor activity in two species of Rehmannia, R. piasezkii and wild R. glutinosa, HPLC methods were used to detect the contents of glycosides in plants of different origins of R. piasezkii and wild R. glutinosa. Chemometric techniques and the EW-TOPSIS method were used to analyze the result. The MTT assay was applied to test the effects of different concentrations of them on the proliferation of HepG2 cells. This study conducted correlation analysis to evaluate the quality of the two species of Rehmannia. In the roots, leaves, flowers, and stems of R. piasezkii and wild R. glutinosa, catalpol, rhmannioside D, rhmannioside A, ajugol, rhodiroside, acteoside, isoacteoside, and 2'-acetylacteoside were detected, with catalpol and acteoside having relatively high contents. The results of the cluster analysis show that the samples are generally grouped into two categories based on R. piasezkii and wild R. glutinosa, respectively. The content characteristics of glycosides in the four parts of the two Rehmannia species are generally grouped into root, leaf, flower, and stem, which is consistent with the results of the principal component analysis. The results of the orthogonal partial least squares discriminant analysis further confirmed the interspecies differences and identified the glycosides affecting the interspecies differences between the two types of Rehmannia from different parts: 6 from the roots, 3 from the leaves, 4 from the flowers, and 2 from the stems. The results of EW-TOPSIS show that the overall quality of wild R. glutinosa is superior to that of R. piasezkii, with the quality of the Rehmannia leaf samples being the best. They all had some inhibitory effect on HepG2 cells, but there is no significant difference in anti-tumor activity. The overall inhibition rate of the leaf part was the highest among the four parts in two species of Rehmannia. The results of correlation analysis showed that phenylethanoid glycosides may be the important pharmacological substances with anti-tumor activity in the two species of Rehmannia.This study provides a scientific basis for the chemical composition and pharmacological studies of the Rehmannia plant.

Key words:

Rehmannia piasezkii; wild Rehmannia glutinosa, glycosides, anti-tumor, quality analysis