Anti-mutagenicity of Swertiamarin and Its Metabolite in Incubated System of Human Intestinal Flora

Comprehensive metabolism study of swertiamarin in rats using ultra high-performance liquid chromatography coupled with Quadrupole-Exactive Orbitrap mass spectrometry

Swertiamarin, a natural ingredient with potent pharmacological activities in the iridoid glycoside family, had been reported to have significant therapeutic effects on a variety of human diseases.In this study, a systematic and efficient strategy based on UHPLC-Q-Exactive Orbitrap mass spectrometry was established to reveal the metabolic profile of swertiamarin in rat urine, plasma, and faeces.First of all, post-acquisition data-mining methods, including multiple mass defect filters (MMDFs) and high-resolution extracted ion chromatograms (HREICs), were developed to screen the metabolite candidates of swertiamarin from the complete mass scan data sets.Second, according to the diagnostic product ions (DPIs), neutral loss fragments (NLFs), chromatographic retention time, accurate mass measurement and calculated Clog P values, all metabolite candidates were rapidly identified.As a consequence, 49 metabolites altogether, including archetype compound, were preliminarily characterised. The corresponding in vivo biotransformation processes, such as dehydration, dehydrogenation, hydroxylation, hydrogenation, methylation, sulphonation, N-acetylcysteine (NAC) formation, N-heterocyclisation and their composite reactions, were all discovered in the study.In conclusion, our results not only detailedly elucidated many new metabolites and metabolic pathways of swertiamarin, but also provided a reference for further study of its pharmacological mechanism and evaluation of its safety.

Gut microbial transformation, a potential improving factor in the therapeutic activities of four groups of natural compounds isolated from herbal medicines

Herbal medicines (HMs) have attracted widespread attention because of their significant contributions to the prevention and treatment of many human diseases. Recently, gut microbiota has become an important frontier to understand the therapeutic mechanisms of medicines. Gut microbiota-mediated transformation is a microbial metabolic form after oral administrations of HMs compounds. A great number of studies showed that gut microbiota could transform some HMs compounds by the variation of chemical structures into several active metabolites, which exerted better bioavailabilities and therapeutic activities than their parent compounds. Among these HMs compounds, alkaloids, flavonoids, polyphenols and terpenoids were the representative ones. However, there is no systemic review focusing on the potential improved therapeutic activities of these natural compounds caused by gut microbial transformation. Here, this review summarizes the therapeutic activities that are more potent in microbial transformed metabolites than in their parent compounds (alkaloids, flavonoids, polyphenols and terpenoids) from HMs. We hope this review will be conducive to deepening the understanding of the relationship between gut microbial transformation and therapeutic activities of HMs compounds.