Ginsenosides, absorption

Odani, T., Tanizawa, H., and Takino, Y. (1983a). Studies on the absorption, distribution, excretion and metabolism of ginseng saponins. 11. The absorption, distribution and excretion of ginsenoside Rgi in the rat. Chem. Pharm. Bull. 31, 292-298. 

Takino Y, Odani T, Tanizawa FI, Flayashi T. (1982). Studies on the absorption, distribution, excretion, and metabolism of ginseng saponins I. Quantitative analysis of ginsenoside Rgl in rats. Chem Pharm Bull (Tokyo). 30(6) 2196-201. 

The amount of nonmetabolized intact Rgj and Rb2 absorbed by the gastrointestinal tract of the rat is about 1.9 and 0.1% of the doses, respectively.28 With a whole-body autoradiography, Strombom et al.29 (Figure 16.29) have been able to demonstrate in rats the absorption and distribution of the radioactively labeled ginsenoside Rgj and its metabolites after per oral administration of a radioactively labeled ginsenoside Rgj isolated from the G115 extract. 

J. Stombom et al., Studies on absorption and distribution of ginsenoside Rgj by whole-body autoradiography and chromatography, Acta Pharm. Suec., 22, 113, 1985. 

Takino, Y., T. Odani, H. Tanizawa, and T. Hayashi Studies on the Absorption, Distribution, Excretion and Metabolism of Ginseng Saponins. I. Quantitative Analysis of Ginsenoside Rgi in Rats. Chem. Pharm. Bull. (Japan) 30, 2196 (1982). 

Spectrophotometric detection is generally used and the choice of solvents is limited to those with low absorption properties. Especially, acetonitrile, tetra-hydrofuran, methanol, or isopropanol and, less commonly, dioxan (which can be used for the separation of cardiac glycosides and derivatives of amino acids) have been found to be sufficiently selective in most cases. Water is used to adjust solvent strength and the addition of acid (preferably orthophosphoric acid, although acetic and formic acids can be used, especially if MS detection is hyphenated) or buffer in RPLC will decrease peak tail. A typical sample of the use of an ammonium buffer is reported for the HPLC analysis of both neutral and acid ginsenosides (Figure 3). 

Low UV absorptivity is also true for the compound class of ginsenosides. These compounds are triterpenic (steroidal) saponins, which are considered to be the main bioactive constituents in Panax ginseng and a related species P. quinquefolius (American ginseng) with antistress, antihyperglycemic, and potential antitumor properties. There are seven major ginsenosides present in P. 

Karikura M, Miyase T, Tanizawa H, Takino Y (1991) Studies on absorption, distribution, excretion and metabolism of ginseng saponins. VI. The decomposition products of ginsenoside Rb2 in the stomach of rats. Chem Pharm Bull (Tokyo) 39 400-404. 

Han M, Fang XL (2006) Difference in oral absorption of ginsenoside Rgl between in vitro and in vivo models. Acta Pharmacol Sin 27 499-505... 

Xiong J, Sun M, Guo J, Huang L, Wang S, Meng B, Ping Q (2009) Enhancement by adrenaline of ginsenoside Rgl transport in Caco-2 cells and oral absorption in rats. J Pharm Pharmacol 61 347-352... 

Han M, Fu S, Gao JQ, Fang XL (2009) Evaluation of intestinal absorption of ginsenoside Rgl incorporated in microemulsion using parallel artificial membrane permeability assay. Biol Pharm Bull 32 1069-1074... 

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