Development and validation of a UFLC-MS/MS method for simultaneous quantification of sixty-six saponins and their six aglycones: Application to comparative analysis of red ginseng and white ginseng.

A new and sensitive ultra fast liquid chromatography coupled with electrospray ionization triple quadrupole tandem mass spectrometry (UFLC-MS/MS) method was developed to evaluate the quality of Red ginseng (RG) and to find out its chemical markers by comparing with multi-batches of RG and white ginseng (WG). This innovative method could quantify sixty-six saponins and their six aglycones including 10 pairs of 20(S) and 20(R) epimers within 35 min simultaneously. All compounds could be determined in individual multiple-reaction monitoring channel without interference, and the optimized method was rapid, accurate, precise, reproducible and efficient. Using the orthogonal partial least squared discriminant analysis, ginsenosides Rg5, Rh4, Rk1, Rs4, F4, and 20(S)-Rg3 were found to be the characteristic components of RG, the six compounds should be suggested as quality control markers to distinguish RG from WG. These findings will be significant for standardizing the processing procedures of RG and ensuring the consistent quality, as well as consequently the efficacy of RG in clinical applications. Results will be helpful in providing crucial chemical profiles of RG.

Simultaneous quantification of twenty-one ginsenosides and their three aglycones in rat plasma by a developed UFLC-MS/MS assay: Application to a pharmacokinetic study of red ginseng.

To track the pharmacokinetic features of red ginseng (RG), a rapid and sensitive ultra fast liquid chromatographic coupled with electrospray ionization triple quadrupole tandem mass spectrometry (UFLC-MS/MS) method was developed for simultaneous quantification of twenty-one ginsenosides and their three aglycones, including 18 prototype compounds (ginsenosides Rb1, Rb2, Rc, Rd, Re, Rg1, Rg5, Rh4, Rk1, Rk3, 20(S)-Rf, 20(S)-Rg2, 20(R)-Rg2, 20(S)-Rg3, 20(R)-Rg3, 20(S)-Rh1, 20(R)-Rh1, 20(S)-NG-R2), and 6 metabolites (ginsenosides 20(S)-Rh2 and Rh3, 20(S)-protopanaxadiol (PPD), 20(S)-protopanaxatriol (PPT), 20(R)-PPT, ginseng saponin compound K) of RG in rat plasma after oral administration of RG water extract at a single dose of 4g/kg body weight to rats. All analytes with internal standard (digoxin) were detected by multiple reaction monitoring in negative ionization mode and separated on an ACQUITY UPLC® BEH RP-C18 column (1.7µm, 100×2.1mm). This established method was well validated in terms of linearity, sensitivity, intra- and inter-day precisions, accuracy, recovery, matrix effect, stability, and had a lower limit of quantification at the concentration range of 0.12-8.12ng/mL for all of analytes. This UFLC-MS/MS approach was successfully applied to the pharmacokinetic study for RG water extract in rats. We firstly proposed that Rb1, Rb2, Rc, Rd, Rg1, Rg5, 20(S)-Rg3, 20(S)-Rh2, and 20(S)-PPD measured in rat plasma were suitable pharmacokinetic markers of RG extract in rats due to their high systemic exposure levels. Thus, this specific and reliable method will be useful for future applications to pharmacokinetic studies for various sources of ginsenoside samples and Panax herbs in vivo.

Inhibition of advanced glycation end product formation by Pu-erh tea ameliorates progression of experimental diabetic nephropathy.

Accumulation of advanced glycation end products (AGEs) has been implicated in the development of diabetic nephropathy. We investigated the effects of Pu-erh tea on AGE accumulation associated with diabetic nephropathy. Although it did not affect blood glucose levels and insulin sensitivy, Pu-erh tea treatment for 8 weeks attenuated the increases in urinary albumin, serum creatinine, and mesangial matrix in db/db mice. We found that Pu-erh tea prevented diabetes-induced accumulation of AGEs and led to a decreased level of receptor for AGE expression in glomeruli. Both production and clearance of carbonyl compounds, the main precursor of AGE formation, were probably attenuated by Pu-erh tea in vivo independent of glyoxalase I expression. In vitro, HPLC assay demonstrated Pu-erh tea could trap methylglyoxal in a dose-dependent manner. Our study raises the possibility that inhibition of AGE formation by carbonyl trapping is a promising approach to prevent or arrest the progression of diabetic complications.