RESUMO
Panax notoginseng saponins (PNSs) are the major health-beneficial components of P. notoginseng with very low oral bioavailability, which could be biotransformed by gut microbiota in vitro. However, in vivo biotransformation of PNS mediated by gut microbiota is not well known. This study aimed to characterize the in vivo metabolic profiles of PNS mediated by gut microbiota. The saponins and yielded metabolites in rat feces were identified and relatively quantified by ultra-performance liquid chromatography tandem/quadrupole time-of-flight mass spectrometry. Seventy-three PNS metabolites had been identified in the normal control group, but only 11 PNS metabolites were determined in the pseudo germ-free (GF) group. In addition, the main biotransformation pathway of PNS metabolism was hydrolytic and dehydration reactions. The results indicated that a significant metabolic difference was observed between the normal control group and pseudo GF group, while gut microbiota played a profound role in the biotransformation of PNS in vivo.
Assuntos
Bactérias/metabolismo , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/metabolismo , Microbioma Gastrointestinal , Panax notoginseng/metabolismo , Saponinas/química , Saponinas/metabolismo , Animais , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Biotransformação , Fezes/microbiologia , Masculino , Panax notoginseng/química , Ratos , Ratos Sprague-DawleyRESUMO
Panax notoginseng saponins (PNS) are the major components of Panax notoginseng, with multiple pharmacological activities but poor oral bioavailability. PNS could be metabolized by gut microbiota in vitro, while the exact role of gut microbiota of PNS metabolism in vivo remains poorly understood. In this study, pseudo germ-free rat models were constructed by using broad-spectrum antibiotics to validate the gut microbiota-mediated transformation of PNS in vivo. Moreover, a high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) was developed for quantitative analysis of four metabolites of PNS, including ginsenoside F1 (GF1), ginsenoside Rh2 (GRh2), ginsenoside compound K (GCK) and protopanaxatriol (PPT). The results showed that the four metabolites could be detected in the control rat plasma, while they could not be determined in pseudo germ-free rat plasma. The results implied that PNS could not be biotransformed effectively when gut microbiota was disrupted. In conclusion, gut microbiota plays an important role in biotransformation of PNS into metabolites in vivo.