Alismatis rhizoma (AR) has been used as an herbal medicine in China for over a thousand years. Crude AR, salt-processed AR (SAR), and bran-processed AR (BAR) are recorded in the Pharmacopoeia of the People′s Republic of China. However, the differences of chemical composition between crude AR and its processing products remain limited. In this study, triterpenes were identified from crude AR, SAR, and BAR by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight-mass spectrometer (UHPLC-QTOF-MS/MS). Subsequently, the differences of triterpenes between the crude AR and processed ARs were compared via a targeted metabolomics approach. Finally, a total of 114 triterpenes were identified, of which 83, 100, and 103 triterpenes were found in crude AR, SAR, and BAR, respectively. After salt-processing, there were 17 triterpenes newly generated, 7 triterpenes with trends of increasing, and 37 triterpenes decreased. Meanwhile, 56 triterpenes including 21 newly generated and 35 with significant increases were observed in BAR. This study could be benefit to investigate the processing mechanism of AR, as well as support their clinical applications.

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver disorders worldwide and had no approved pharmacological treatments. Diwuyanggan prescription (DWYG) is a traditional Chinese medicine preparation composed of 5 kinds of herbs, which has been used for treating chronic liver diseases in clinic. Whereas, the synergistic mechanism of this prescription for anti-NAFLD remains unclear. In this study, we aimed to demonstrate the synergetic effect of DWYG by using the disassembled prescriptions and untargeted metabolomics research strategies. The therapeutic effects of the whole prescription of DWYG and the individual herb were divided into six groups according to the strategy of disassembled prescriptions, including DWYG, Artemisia capillaris Thunb. (AC), Curcuma longa L. (CL), Schisandra chinensis Baill. (SC), Rehmannia glutinosa Libosch. (RG) and Glycyrrhiza uralensis Fisch. (GU) groups. The high fat diets-induced NAFLD mice model was constructed to evaluate the efficacy effects of DWYG. An untargeted metabolomics based on the UPLC-QTOF-MS/MS approach was carried out to make clear the synergetic effect on the regulation of metabolites dissecting the united mechanisms. Experimental results on animals revealed that the anti-NAFLD effect of DWYG prescription was better than the individual herb group in reducing liver lipid deposition and restoring the abnormality of lipidemia. In addition, further metabolomics analysis indicated that 23 differential metabolites associated with the progression of NAFLD were identified and 19 of them could be improved by DWYG. Compared with five single herbs, DWYG showed the most extensive regulatory effects on metabolites and their related pathways, which were related to lipid and amino acid metabolisms. Besides, each individual herb in DWYG was found to show different degrees of regulatory effects on NAFLD and metabolic pathways. SC and CL possessed the highest relationship in the regulation of NAFLD. Altogether, these results provided an insight into the synergetic mechanisms of DWYG from the metabolic perspective, and also supported a scientific basis for the rationality of clinical use of this prescription.