UPLC-Q-TOF/MS based fecal metabolomics reveals the potential anti-diabetic effect of Xiexin Decoction on T2DM rats.

Xiexin Decoction (XXD), a traditional Chinese medicine prescription composed of Rhei rhizome (RR), Scutellaria radix (SR) and Coptidis rhizome (CR), has been used to cure diabetes in clinical practices for thousands of years, but its mechanism is not clear. Our previous study indicated that XXD could significantly ameliorate the symptom of type 2 diabetes mellitus (T2DM) rats by shifting the composition of gut microbiota. However, the effect of XXD on the metabolic activity of gut microbiota is not clarified. In this study, the underlying mechanism of XXD on the amelioration of T2DM was explored by fecal metabolic profiling analysis based on ultra performance liquid chromatography coupled with quadrupole time-of-fight mass spectrometry (UPLC-Q-TOF/MS). The disordered metabolic profiles in T2DM rats were notably improved by XXD. Ten potential biomarkers, which were mainly involved in arachidonic acid metabolism, amino acid metabolism, bile acid metabolism, glycolysis and gluconeogenesis, were identified. Furthermore, these metabolites were closely related to SCFAs-producing and anti-inflammatory gut microflora. After XXD intervention, these biomarkers restored to the normal level at some extent. This study not only revealed potential biomarkers and related pathways in T2DM rats affected by XXD, but also provided a novel insight to uncover how traditional herb medicines worked from fecal metabolomics.

A Powerful HPLC-ELSD Method for Simultaneous Determination of Fecal Bile Acids in T2DM Rats Interfered by Sanhuang Xiexin Tang.

Bile acids (BAs) as important endogenous ligands can activate farnesoid X receptor (FXR) and G-protein-coupled bile acid receptor 1 (GPBAR1, also known as TGR5) signaling to regulate glycolipid metabolism. In this study, a simple, reliable and sensitive analysis method for simultaneous determination of four BAs from rat feces based on high-performance liquid chromatography with evaporative light scattering detector (HPLC-ELSD) was developed. Chromatographic analysis was performed with the mobile phases of acetonitrile and 0.2% formic acid. All the standard curves exhibited good linearity (R2 ≥ 0.99). The relative standard deviations of precision, stability and repeatability varied from 1.27 to 3.96%, 2.20 to 3.89% and 3.00 to 4.31%, respectively. The validated method was successfully applied to investigate the variation of four BAs in feces from T2DM rats after oral administration of Sanhuang Xiexin Tang (SXT). Data showed that SXT could remarkably increase the contents of conjunct BAs and decrease the contents of free BAs, which might contribute to ameliorate the symptoms of T2DM rats.

Protective effects of Lizhong decoction on ulcerative colitis in mice by suppressing inflammation and ameliorating gut barrier.

ETHNOPHARMACOLOGICAL RELEVANCE: Lizhong Decoction (LZD) is a classical prescription firstly recorded in "Shanghan Lun". It has been used to clinically treat ulcerative colitis (UC) for thousands of years. However, its mechanism is not clear up to now. AIM OF THE STUDY: The goal of this study was to assess the amelioration of LZD on dextran sodium sulfate (DSS)-induced colitis in mice and further clarify its mechanism. MATERIALS AND METHODS: The ulcerative colitis model induced by DSS was successfully established and applied to evaluate the intervention effect after oral administration of LZD. Furthermore, the expression of key targets in inflammatory signaling pathways and intestinal tight junction proteins were investigated by enzyme-linked immunosorbent assay (ELISA) and quantitative real time polymerase chain reaction (qPCR) analysis. RESULTS: The results showed that all doses of LZD could notably improve DSS-induced colon lesions, reduce histological scores, prolong colon length and increase body weight. Colonic inflammation in UC mice was significantly alleviated by inhibiting the activities of myeloperoxidase (MPO) and superoxide dismutase (SOD), reducing the yield of nitric oxide (NO) and inflammatory cytokines such as interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and interleukin-6 (IL-6), and along with promoting the production of anti-inflammatory cytokines such as interleukin-4 (IL-4) and interleukin-10 (IL-10) after LZD treatment. Furthermore, LZD remarkably down-regulated the level of toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) mRNA and up-regulated the expression of tight junction proteins (zonula occluden-1, occludin and claudin-1) in UC mice. CONCLUSION: In summary, this study indicated that LZD could notably improve UC symptoms by suppressing inflammation and ameliorating gut barrier, which provided scientific basis for its clinical application in the future.

Lizhong decoction ameliorates ulcerative colitis in mice via modulating gut microbiota and its metabolites.

Ulcerative colitis (UC), a kind of inflammatory bowel disease, is generally characterized by chronic, persistent, relapsing, and nonspecific ulceration of the bowel, which is widespread in the world. Although the pathogenesis of UC is multifactorial, growing evidence has demonstrated that gut microbiota and its metabolites are closely related to the development of UC. Lizhong decoction (LZD), a well-known classical Chinese herbal prescription, has been used to clinically treat UC for long time, but its mechanism is not clear. In this study, 16S rRNA gene sequencing combining with untargeted metabolomics profiling was used to investigate how LZD worked. Results indicated that LZD could shape the gut microbiota structure and modify metabolic profiles. The abundance of opportunistic pathogens such as Clostridium sensu stricto 1, Enterobacter, and Escherichia-Shigella correlated with intestinal inflammation markedly decreased, while the levels of beneficial bacteria including Blautia, Muribaculaceae_norank, Prevotellaceae UCG-001, and Ruminiclostridium 9 elevated in various degrees. Additionally, fecal metabolite profiles reflecting microbial activities showed that adenosine, lysoPC(18:0), glycocholic acid, and deoxycholic acid notably decreased, while cholic acid, α-linolenic acid, stearidonic acid, and L-tryptophan significantly increased after LZD treatment. Hence, based on the systematic analysis of 16S rRNA gene sequencing and metabolomics of gut flora, the results provided a novel insight that microbiota and its metabolites might be potential targets for revealing the mechanism of LZD on amelioration of UC.Key Points • The potential mechanism of LZD on the amelioration of UC was firstly investigated.• LZD could significantly shape the structure of gut microbiota.• LZD could notably modulate the fecal metabolic profiling of UC mice. Graphical abstract.

Scutellariae radix and coptidis rhizoma ameliorate glycolipid metabolism of type 2 diabetic rats by modulating gut microbiota and its metabolites.

Scutellariae radix (Scutellaria baicalensis Georgi, SR) and coptidis rhizoma (Coptis chinensis Franch, CR) are both widely used traditional Chinese medicines and have been used together to treat T2DM with synergistic effects in the clinical practices for thousands of years, but their combination mechanism is not clear. Accumulating evidences have implicated gut microbiota as important targets for the therapy of T2DM. Thus, this study aimed to unravel the cooperation mechanism of SR and CR on the amelioration of T2DM based on the systematic analysis of metagenome and metabolome of gut microbiota. Bacterial communities were analyzed based on high-throughput 16S rRNA gene sequencing. Furthermore, ultra high-performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UPLC-Q-TOF-MS) was used to analyze variations of microbial metabolites in feces and the contents of short chain fatty acids (SCFAs) in the cecum were determined by a gaschromatography-flame ionization detector (GC-FID). 16S rRNA gene sequencing results revealed that T2DM rats treated with SR, CR, and the combination of SR and CR (SC) exhibited changes in the composition of the gut microbiota. The SCFAs-producing bacteria such as Bacteroidales S24-7 group_norank, [Eubacterium] nodatum group, Parasutterella, Prevotellaceae UCG-001, Ruminiclostridium, and Ruminiclostridium 9 in T2DM rats were notably enriched after treatment with SR, CR, and their combination. In contrast, secondary bile acid-producing bacteria such as Escherichia-Shigella strongly decreased in numbers. The perturbance of metabolic profiling in T2DM rats was obviously improved after treatment, exhibiting a lower level of secondary bile acids and a numerical increase of microbially derived SCFAs. Moreover, the correlation analysis illustrated a close relationship among gut microbiota, its metabolites, and T2DM-related indexes. The findings indicated that the crosstalk between microbiota-derived metabolites and the host played an important role in the progress of T2DM and might provide a novel insight regarding gut microbiota and its metabolites as potential new targets of traditional Chinese medicines. Furthermore, this work also suggested that the integration of various omics methods and bioinformatics made a useful template for drug mechanism research.

Xiexin Tang ameliorates dyslipidemia in high-fat diet-induced obese rats via elevating gut microbiota-derived short chain fatty acids production and adjusting energy metabolism.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional herbal medicine has been taken as a new and effective approach to treat many chronic diseases. Xiexin Tang (XXT), a compound recipe composed of Dahuang (Rheum palmatum L.), Huangqin (Scutellaria baicalensis Georgi) and Huanglian (Coptis chinensis Franch.), has been reported to have hypoglycemic and hypolipidemic effects, but its mechanism remains unclear. Our previous study found that Xiexin Tang markedly ameliorated the composition of the gut microbiota, especially for some short chain fatty acids (SCFAs) producing bacteria, and then notably increased SCFAs production. However, the mechanism of XXT on the fermentation of gut bacteria and further improvement of obesity is not yet clear. AIM OF THE STUDY: This study aimed to unravel the molecular mechanism of XXT on the amelioration of obesity. MATERIALS AND METHODS: Here, high-fat diet-induced obese rat model was established to investigate the intervention efficacy following oral administration of XXT. Additionally, the expressions of key enzymes of gut microbe-derived SCFAs biosynthesis and key targets in the signaling pathway of energy metabolism were investigated by ELISA and qPCR analysis. RESULTS: Results showed that XXT could notably correct lipid metabolism disorders, alleviate systematic inflammation, improve insulin sensitivity and reduce fat accumulation. Additionally, XXT could increase gut microbiota-derived SCFAs-producing capacity by enhancing mRNA levels and activities of SCFA-synthetic key enzymes such as acetate kinase (ACK), methylmalonyl-CoA decarboxylase (MMD), butyryl-CoA: acetate CoA transferase (BUT) and butyrate kinase (BUK), which markedly decreased the adenosine triphosphate (ATP) contents, elevated adenosine diphosphate (ADP) and adenosine monophosphate (AMP) levels and further lowered the energy charge (EC) in obese rats via activating peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)/uncoupling protein-2 (UCP-2) signaling pathway. What's more, XXT could notably ameliorate dyslipidemia via increasing the gene expression of 5'-AMP-activated protein kinase (AMPK) and blocking mammalian target of rapamycin (mTOR) signaling pathway. CONCLUSIONS: Taken together, our data provided a novel insight into the role of XXT in losing weight from energy metabolism regulation, which unraveled the molecular mechanism of XXT on the alleviation of dyslipidemia and fat heterotopic accumulation. The study provided useful information for XXT in clinical application to treat obesity.