Elaboration of the Comprehensive Metabolic Profile of Salvianolic Acid A in Vivo and in Vitro Using UFLC-Q/TOF-MS

Gut microbiota: a superior operator for dietary phytochemicals to improve atherosclerosis

Mounting evidence implicates the gut microbiota as a possible key susceptibility factor for atherosclerosis (AS). The employment of dietary phytochemicals that strive to target the gut microbiota has gained scientific support for treating AS. This study conducted a general overview of the links between the gut microbiota and AS, and summarized available evidence that dietary phytochemicals improve AS via manipulating gut microbiota. Then, the microbial metabolism of several dietary phytochemicals was summarized, along with a discussion on the metabolites formed and the biotransformation pathways involving key gut bacteria and enzymes. This study additionally focused on the anti-atherosclerotic potential of representative metabolites from dietary phytochemicals, and investigated their underlying molecular mechanisms. In summary, microbiota-dependent dietary phytochemical therapy is a promising strategy for AS management, and knowledge of "phytochemical-microbiota-biotransformation" may be a breakthrough in the search for novel anti-atherogenic agents.

Metabolite identification of salvianolic acid A in rat using post collision-induced dissociation energy-resolved mass spectrometry

BACKGROUND

As one of the most famous natural products, salvianolic acid A (SAA) is undergoing clinical trials for the treatments of angina pectoris and coronary heart disorders. However, the in vivo metabolites of SAA have only been tentatively identified, leading to a barrier for precise therapeutical drug monitoring.

METHODS

Ultra-high performance liquid chromatography coupled with quadrupole time of flight tandem mass spectrometry (UPLC-Qtof-MS/MS) was firstly employed to acquire high-resolution MS1 and MS2 spectra for all metabolites. Through paying special attention onto the features of ester bond dissociation, metabolism sites were restricted at certain regions. To further determine the metabolism site, such as the monomethylated products (M23, M25, and M26), post collision-induced dissociation energy-resolved mass spectrometry (post-CID ER-MS) was proposed through programming progressive exciting energies to the second collision chamber of hybrid triple quadrupole-linear ion trap mass spectrometry (Qtrap-MS) device.

RESULTS

After SAA oral administration, 29 metabolites (M1-M29), including five, thirteen, and sixteen ones in rat plasma, urine, and feces, respectively, were detected in rats. The metabolism route was initially determined by applying well-defined mass fragmentation pathways to those HR-m/z values of precursor and fragment ions. Metabolism site was limited to SAF- or DSS-unit based on the fragmentation patterns of ester functional group. Through matching the dissociation trajectories of concerned 1st-generation fragment ions with expected decomposition product anions using post-CID ER-MS strategy, M23 and M25 were unequivocally assigned as 3'-methyl-SAA and 3''-methyl-SAA, and M26 was identified as 2-methyl-SAA or 3-methyl-SAA. Hydrolysis, methylation, glucuronidation, sulfation, and oxidation were the primary metabolism channels being responsible for the metabolites' generation.

CONCLUSION

Together, the metabolism regions and sites of SAA metabolites were sequentially identified based on the ester bond dissociation features and post-CID ER-MS strategy. Importantly, the present study provided a promising way to elevate the structural identification confidence of natural products and metabolites.

Virtual screening and network pharmacology-based synergistic mechanism identification of multiple components contained in Guanxin V against coronary artery disease

BACKGROUND

Guanxin V (GXV), a traditional Chinese medicine (TCM), has been widely used to treat coronary artery disease (CAD) in clinical practice in China. However, research on the active components and underlying mechanisms of GXV in CAD is still scarce.

METHODS

A virtual screening and network pharmacological approach was utilized for predicting the pharmacological mechanisms of GXV in CAD. The active compounds of GXV based on various TCM-related databases were selected and then the potential targets of these compounds were identified. Then, after the CAD targets were built through nine databases, a PPI network was constructed based on the matching GXV and CAD potential targets, and the hub targets were screened by MCODE. Moreover, Metascape was applied to GO and KEGG functional enrichment. Finally, HPLC fingerprints of GXV were established.

RESULTS

A total of 119 active components and 121 potential targets shared between CAD and GXV were obtained. The results of functional enrichment indicated that several GO biological processes and KEGG pathways of GXV mostly participated in the therapeutic mechanisms. Furthermore, 7 hub MCODEs of GXV were collected as potential targets, implying the complex effects of GXV-mediated protection against CAD. Six specific chemicals were identified.

CONCLUSION

GXV could be employed for CAD through molecular mechanisms, involving complex interactions between multiple compounds and targets, as predicted by virtual screening and network pharmacology. Our study provides a new TCM for the treatment of CAD and deepens the understanding of the molecular mechanisms of GXV against CAD.