Absorption and Metabolism of Astragali Radix Decoction: In Silico, in Vitro, and a Case Study in Vivo

Abstract

ABSTRACT:To profile absorption of Astragali Radix decoction and identify its orally absorbable constituents and their metabolites, four complementary in silico, in vitro, and in vivo methods, i.e., a computational chemistry prediction method, a Caco-2 cell monolayer model experiment, an improved rat everted gut sac experiment, and a healthy human volunteer experiment, were used. According to the in silico computation result, 26 compounds of Astragali Radix could be regarded as orally available compounds, including 12 flavonoids. In the in vitro and in vivo experiments, 21 compounds were tentatively identified by high-performance liquid chromatography-diode array detection-electrospray ion trap tandem mass spectrometry data, which involved calycosin, formononetin, (6aR,11aR)-3-hydroxy-9,10-dimethoxypterocarpan, 7,2-dihydroxy-3,4-dimethoxyisoflavan, calycosin We found that besides isoflavones, pterocarpans and isoflavans also could be metabolized by the intestine during absorption, and the major metabolites were glucuronides. In conclusion, the present study demonstrated that the flavonoids in Astragali Radix decoction, including isoflavones, pterocarpans, and isoflavans, could be absorbed and metabolized by the intestine. These absorbable compounds, which were reported to have various bioactivities related to the curative effects of Astragali Radix decoction, could be regarded as an important component of the effective constituents of Astragali Radix decoction.

The Presystemic Interplay between Gut Microbiota and Orally Administered Calycosin-7-O-β-d-Glucoside

“…Calycosin phase II conjugates appeared to be the primary circulating forms present after an oral administration of C7G to rats (Chen et al, 2011;Zhang et al, 2012) or administration of Astragali Radix extract to a healthy volunteer (Xu et al, 2006). These findings indicate the occurrence of deglycosylation of C7G and further conjugation of calycosin.…”

Astragali Radix elicits anti-inflammation via activation of MKP-1, concomitant with attenuation of p38 and Erk

“…HPLC analysis of AR displayed the presence of several secondary metabolites such as polyphenolic flavonoids including formononetin (Fig. 6), which have various biological effects on cell signaling, cell division and growth, and gene expression (Kousidou et al, 2006;Xu et al, 2006), and are presumed to contribute, at least in part, to the anti-inflammation effects of AR. Although additional studies are required to determine indeed potential compound(s) and their in vivo mechanisms, it seems that polyphenolic flavonoid(s) from AR may have important implications for clinical applications.…”

Metabolism of Echinacoside, a Good Antioxidant, in Rats: Isolation and Identification of Its Biliary Metabolites

“…In recent years, new techniques were applied to identify and characterize the metabolites, such as gas chromatography-MS, LC-MS (Rüfer et al, 2006;Xu et al, 2006), LC/NMR (Mutlib and Shockcor, 2003), NMR (Zhang et al, 2004;Zeng et al, 2007), and stable isotopes. In our study, three groups of positional isomers (M5, M6, M7, and M8; M1 and M2; and M3 and M4) were obtained.…”