Interaction Studies Between Flavanone Glycosides And Isoflavone Glycosideswith Human Intestinal Bacteria

Human intestinal bacteria can metabolize drugs and drugs can affect the growth of intestinal bacteria. On one hand, after drugs oral administration into the intestine, resulting in a variety of intestinal microflora play a role in drug metabolism inevitably, to produce metabolites that have different biological activity. On the other hand, most traditional medicines need long-term administration, a variety of complex components contained in medicines will have some impact on the balance of intestinal bacteria in the process, while the balance of intestinal flora is closely related to human health. Studies about interaction between human intestinal bacteria and flavonoid glycosides have not started systematically. Therefore, this paper selected naringin, liquiritin, hesperidin, neohesperidin, calycosin-7-O-β-D-glycoside and ononin to study bacterial metabolic pathways of them and their impact on the growth of intestinal bacteria. The main objectives of this researeh were helpful to reveal the mechanism of traditional Chinese medicines and clinical application of medicines which containing such ingredients in vivo after oral administration.Firstly, six flavonoid glycosides:naringin, liquiritin, hesperidin, neohesperidin, calycosin-7-O-β-D-glycoside and ononin had been incubated under anaerobic condition with the intestinal mixture and the sixty nine isolated bacteria, respectively. The intestinal bacteria, capable of metabolizing these flavonoid glycosides were screened to identify by16SrRNA. Additionally, in this study, an ultra performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/QTOF-MS) technique combined with MetabolynxTM software was established and applied for the detection and identification of the metabolites of six flavonoid glycosides.According to the results we find that intestinal bacteria could metabolize them to their aglycone and the acetylated, hydrogenated, methylated, dehydroxylated and demethoxylated metabolites respectively. These metabolites produced by intestinal bacteria have never been reported before. Furthermore, the possible metabolism pathways about these flavonoid glycosides are established. Thus, we could conclude that there are two main metabolism pathways of flavonoid glycosides, deglycosylation is the most predominant metabolic pathway by intestinal bacteria, and then aglycones could conversion to other ingredients; secondly prototypes biotransformated into other metabolites directly. This study will be helpful for understanding the metabolic rout of flavonoid glycosides and the role of different intestinal bacteria on the metabolism of natural compounds.Using UPLC-TQ/MS to determinate flavonoid glycosides and their metabolites in the intestinal incubation solution by incubated them with the intestinal mixture under the anaerobic condition within24h. Experimental results showed that content of prototype coming down gradually in this period, the contents of their metabolites showed two trends. One trend is some of their metabolites’ contents increased gradually over time, while the other metabolites’contents increased at the first time but decreased subsequently, this suggested that the metabolite may be metabolized to other products by intestinal bacteria.Four typical categories including Enterococcous sp., Enterobacter sp., Lactobacilli sp., and Bifidobacteria sp. were cultured and isolated by selective medium. An emax precision microplate reader was employed to determine the growth situation of Enterococcous sp., Enterobacter sp., Lactobacilli sp., and Bifidobacteria sp in the presence of the six different flavonoid glycosides.The results indicated that flavonoid glycosides can inhibit the growth of pathogen such as Enterococcus sp., Enterobacter sp. and this effect is usually elevated with flavonoid glycosides concentrations enhanced, while flavonoid glycosides can promote the growth of probiotics such as bifidobacteria sp and this effect is weakened with flavonoid glycosides concentrations enhanced regularly. This study suggested that flavonoid glycosides can affect the balance of intestinal flora and the degree of influence varies depending on the bacterial species and the concentration of flavonoid glycosides.Thus, the study on the metabolism of flavonoid glycosides by intestinal bacteria is helpful for fully understanding the mechanism of absorption, metabolism and action of these compounds in vivo, laying the foundation for flavonoid glycosides’possible biotransformation industry, and to provide for rational dosage for clinical applications. In addition, the research methods also provide a reference for similar studies.