Intestinal Absorption Profile of Three Polygala Oligosaccharide Esters in Polygalae Radix and the Effects of Other Components in Polygalae Radix on Their Absorption.

Yinying Ba,Yanyan Jiang,Kunfeng Zhang,Hang Lv,Renbing Shi,Qijun Chen,Menglin Wang,Jiajia Wang

doi:10.1155/2019/1379531

Abstract

Oligosaccharide esters, which are among the main active components of Polygalae Radix (PR), demonstrate significant pharmacological activities in the human nervous system. In our previous research, some other constituents in PR were able to improve the bioavailability of oligosaccharide esters such as sibiricose A5 (SA5), sibiricose A6 (SA6), and 3,6′-disinapoyl sucrose (DISS), but the related components and their underlying mechanisms remain unknown. The present study aimed to investigate the intestinal absorptive profile of SA5, SA6, and DISS and the absorptive behavior influenced by the coadministration of polygalaxanthone III and total saponins of PR (TS) using an in vitro everted rat gut sac model, along with the possible mechanisms that may influence absorption. The results showed that TS could significantly enhance the absorption of SA5, SA6, and DISS monomers. Verapamil, a P-glycoprotein inhibitor, was able to elevate the absorption of SA5 and SA6, and an absorption experiment using Rho123 led us to conclude that TS influenced the absorption of SA5 and SA6 in a manner similar to that of a P-glycoprotein inhibitor. Sodium caprate, a paracellular absorption enhancer, was found to increase the absorption of SA5, SA6, and DISS. Results showed that the absorption mechanisms of SA5 and SA6 may combine active transport with paracellular passive penetration, while DISS's absorption was dominated by paracellular passive penetration. However, the relationship between polygala saponins and the absorption of SA5, SA6, and DISS by paracellular passive penetration remain to be examined. This is the direction of our future research.

Highlights

Polygalae Radix (PR, Yuanzhi), one of the commonly used traditional Chinese medicines (TCM), is derived from the roots of Polygala tenuifolia Willd. or Polygala sibirica L
Papp of disinapoyl sucrose (DISS) in PRE remains basically unchanged with increasing drug concentration. These results suggested that the absorption enhancement of Sibiricose A5 (SA5), sibiricose A6 (SA6), and DISS in PRE and the difference of absorptive profile between the three monomers in PRE versus these monomers alone may be related to the changes in intestinal microenvironment in rat gut induced by other chemicals in the PRE
By using the everted gut sac model, the overall absorption profile of SA5, SA6, and DISS can be enhanced by combination with total saponins of PR (TS), which are other effective components in PR

Summary

Introduction

Polygalae Radix (PR, Yuanzhi), one of the commonly used traditional Chinese medicines (TCM), is derived from the roots of Polygala tenuifolia Willd. or Polygala sibirica L. The major active constituents of PR include oligosaccharide esters, saponins, and xanthones, which have been reported to be related to the therapeutic effect of PR on diseases of the central nervous system [9,10,11]. Recent studies have shown that oligosaccharide esters have significant effects on neuroprotective and antioxidant systems. They cause improvements in the function of the central cholinergic system [12,13,14,15]. Sibiricose A5 (SA5), sibiricose A6 (SA6), and 3,6󸀠-disinapoyl sucrose (DISS) are the main components of oligosaccharide esters [16] These three oligosaccharide esters have been shown to have protective effects in neurotoxicity.

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Results

Conclusion