Metabolism of Soyasaponin I by Human Intestinal Microflora and Its Estrogenic and Cytotoxic Effects

Abstract

-Metabolites of Soyasaponin I, a major constituent of soybean, by human intestinal microflora were investigated by LC-MS/MS analysis. We found four peaks, one parental constituent and three metabolites:which was an unknown metabolite, soyasapogenol B 3-β-D-glucuronide. When soyasaponin I was incubated with the human fecal microbial fraction from ten individuals for 48 h, soyasaponin I was metabolized to soyasapogenol B via soyasaponin III and soyasapogenol B 3-β-D-glucuronide or via soyasaponin III alone. Both soyasaponin I and its metabolite soyasapgenol B exhibited estrogenic activity. Soyasaponin I increased the proliferation, mRNA expression of c-fos and pS2, in MCF7 cells more potently than soyasapogenol B. However, soyasapogenol B showed potent cytotoxicity against A549, MCF7, HeLa and HepG2 cells, while soyasaponin I did not. The cytotoxicity of soyasapogenol B may prevent its estrogenic effect from increasing dose-dependently. These findings suggest that orally administered soyasaponin I may be metabolized to soyasapogenol B by intestinal microflora and that soyasapogenol B may express a cytotoxic effect rather than an estrogenic effect.

Lactobacillus pentosus var. plantarum C29 increases the protective effect of soybean against scopolamine-induced memory impairment in mice

“…These results are consistent with previous report suggesting that soyasaponin I is metabolized to hydrophobic and absorbable compounds by the gut microbiota (Chang et al, 2009). Therefore, to elicit the protective effects of soybean against memory impairment in a gut microbiota-independent manner, we fermented soybean with C29 and measured the effect of FSP in mice with scopolamine-induced memory impairment.…”

“…Similarly, its constituents, isoflavones and saponins, exhibit phytoestrogenic (Pan et al, 2010), anti-inflammatory (Choi et al, 2011;Lee et al, 2010) and memory-enhancing effects (Ding et al, 2011;Hong et al, 2013Hong et al, , 2014Pan et al, 2010;Xi et al, 2013). These constituents (daidzin, genistin, soyasaponins I and Ab) are metabolized to aglycones by gut microbiota (Chang et al, 2009(Chang et al, , 2010Park et al, 2006), and aglycones exhibit more potent phytoestrogenic effects than their parental molecules (Chang et al, 2009;Park et al, 2006).…”

Secretion dynamics of soyasaponins in soybean roots and effects to modify the bacterial composition

“…Soyasaponin Bb is metabolized by human intestinal and fecal microorganisms (Chang, Han, Han, & Kim, 2009; Hu, Zheng, Hyde, Hendrich, & Murphy, 2004), but the microbes that metabolize soyasaponin Bb or soyasaponin Bb‐metabolizing enzymes in soil are yet to be identified. Specific enrichment of microbes by soyasaponin Bb suggests that Novosphingobium possesses a gene set that allows the bacteria to use soyasaponin Bb as a carbon source.…”

Novel PI3K/Akt Inhibitors Screened by the Cytoprotective Function of Human Immunodeficiency Virus Type 1 Tat

“…Lancemasides were isolated from the rhizome of Codonopsis lanceolata according to the previously reported method [27] . Soyasaponin B was isolated from soybean according to the previously reported method [28] . Glycitein and tectoridin were isolated from the flos of Pueraria thunbergiana as previously described [29] .…”