Evaluation of the Saponin Content in Panax vietnamensis Acclimatized to Lam Dong Province by HPLC-UV/CAD.

Minh Duc Nguyen,Hien Minh Nguyen,Huy Truong Nguyen,Huong Thuy Le,Kim Long Vu-Huynh,Jeong Hill Park,Thi Hong Van Le

doi:10.3390/molecules26175373

Abstract

Panax vietnamensis, or Vietnamese ginseng (VG), an endemic Panax species in Vietnam, possesses a unique saponin profile and interesting biological activities. This plant is presently in danger of extinction due to over-exploitation, resulting in many preservation efforts towards the geographical acclimatization of VG. Yet, no information on the saponin content of the acclimatized VG, an important quality indicator, is available. Here, we analyzed the saponin content in the underground parts of two- to five-year-old VG plants acclimatized to Lam Dong province. Nine characteristic saponins, including notoginsenoside-R1, ginsenoside-Rg1, -Rb1, -Rd, majonoside-R1, -R2 vina-ginsenoside-R2, -R11, and pseudoginsenoside-RT4, were simultaneously determined by HPLC coupled with UV and with a charged aerosol detector (CAD). Analyzing the results illustrated that the detection of characteristic ocotillol-type saponins in VG by CAD presented a superior capacity compared with that of UV, thus implying a preferential choice of CAD for the analysis of VG. The quantitative results indicating the saponin content in the underground parts of VG showed an increasing tendency from two to five years old, with the root and the rhizome exhibiting different saponin accumulation patterns. This is the first study that reveals the preliminary success of VG acclimatization and thereby encourages the continuing efforts to develop this valuable saponin-rich plant.

Highlights

Panax vietnamensis Ha et Grushv., commonly known as Vietnamese ginseng (VG), has been long used as a secret herbal medicine by the Sedang ethnic minority in Central Vietnam
This study evaluated nine characteristic saponins in different parts of two- to fiveyear-old VGs, cultivated in Lam Dong, using HPLC–ultraviolet detector (UV)/charged aerosol detector (CAD)
M-R1 significantly increased in both main roots and rhizomes during five years of growth, while M-R2 remained stable as the most abundant compound in the VG’s underground part

Summary

Introduction

Panax vietnamensis Ha et Grushv., commonly known as Vietnamese ginseng (VG), has been long used as a secret herbal medicine by the Sedang ethnic minority in Central Vietnam. Protopanaxatriol-type saponins (PPT-type saponins) such as ginsenoside -R1 (G-Rg1), ginsenoside -Re (G-Re), notoginsenoside-R1 (N-R1), etc., and possesses a unique feature among the Panax genus due to its high content of ocotillol-type saponins (OCT-type saponins) such as majonosideR1 (M-R1), majonoside-R2 (M-R2), vina-ginsenoside-R2 (V-R2), vina-ginsenoside-R11 (VR11), pseudoginsenoside-RT4 (p-RT4), etc. OCT-type saponins account for over 50% of the total saponin content in VG [1,2,3]. Concerning therapeutic value, VG is proven to possess many interesting biological activities such as being anti-melanogenic, anti-oxidative, anti-stress, anti-cancer, hepato-cytoprotective, and having nephroprotective effects against cisplatin toxicity [9,10,11]

Methods

Results

Conclusion