Activation of free fatty acid receptors, FFAR1 and FFAR4, ameliorates ulcerative colitis by promote fatty acid metabolism and mediate macrophage polarization.

OBJECTIVE: To investigate the mechanism of action of fatty acid receptors, FFAR1 and FFAR4, on ulcerative colitis (UC) through fatty acid metabolism and macrophage polarization. METHODS: Dextran sulfate sodium (DSS)-induced mouse model of UC mice was used to evaluate the efficacy of FFAR1 (GW9508) and FFAR4 (GSK137647) agonists by analyzing body weight, colon length, disease activity index (DAI), and histological scores. Real-time PCR and immunofluorescence analysis were performed to quantify the levels of fatty acid metabolizing enzymes and macrophage makers. FFA-induced lipid accumulation in RAW264.7 cells was visualized by Oil Red O staining analysis, and cells were collected to detect macrophage polarization by flow cytometry. RESULTS: The combination of GW9508 and GSK137647 significantly improved DSS-induced UC symptoms, caused recovery in colon length, and decreased histological injury. GW9508 + GSK137647 treatment upregulated the expressions of CD206, lipid oxidation enzyme (CPT-1α) and anti-inflammatory cytokines (IL-4, IL-10, IL-13) but downregulated those of CD86, lipogenic enzymes (ACC1, FASN, SCD1), and pro-inflammatory cytokines (IL-1ß, IL-6, TNF-α). Combining the two agonists decreased FFA-induced lipid accumulation and increased CD206 expression in cell-based experiments. CONCLUSION: Activated FFAR1 and FFAR4 ameliorates DSS-induced UC by promoting fatty acid metabolism to reduce lipid accumulation and mediate M2 macrophage polarization.

Huangqin Decoction ameliorates ulcerative colitis by regulating fatty acid metabolism to mediate macrophage polarization via activating FFAR4-AMPK-PPARα pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Huangqin Decoction (HQD), a traditional Chinese medicine (TCM) formula chronicled in Shang Han Lun, is safe and effective for treatment of ulcerative colitis (UC). AIM OF THE STUDY: To investigate the effect of HQD against dextran sulfate sodium (DSS)-induced UC mice by regulating gut microbiota and metabolites, and further explore the mechanism of fatty acid metabolism on macrophage polarization. MATERIALS AND METHODS: Based on 3% dextran sulfate sodium (DSS)-induced UC mice model, clinical symptoms observation (body weight, DAI, and colon length) and histological inspection were used to evaluate the efficacy of HQD and fecal microbiota transplantation (FMT) from HQD-treated mice. The gut microbiota and metabolites were detected by 16S rRNA sequencing and metabolomics analysis. The parameters of fatty acid metabolism, macrophage polarization, and FFAR1/FFAR4-AMPK-PPARα pathway were analyzed by immunofluorescence analysis, western blotting, and real-time PCR. Then, the effects of FFAR1 and FFAR4 on macrophage polarization were examined by agonists based on LPS-induced RAW264.7 cell model. RESULTS: The results showed that FMT, like HQD, ameliorated UC by improving weight loss, restoring colon length, and reducing DAI scores and histopathological scores. Besides, HQD and FMT both enhanced the richness of gut microbiota, and modulated intestinal bacteria and metabolites to achieve a new balance. Untargeted metabolomics analysis revealed that fatty acids, especially long-chain fatty acids (LCFAs), dominated in HQD against DSS-induced UC by regulating the gut microenvironment. Further, FMT and HQD recovered the expression of fatty acid metabolism-related enzymes, and simultaneously activated FFAR1/FFAR4-AMPK-PPARα pathway but suppressed NF-κB pathway. Combined with cell experiment, HQD and FMT promoted macrophage polarization from M1 toward M2, which were well associated with anti-inflammatory cytokines and combined with the activated FFAR4. CONCLUSIONS: The mechanism of HQD against UC was related to regulating fatty acid metabolism to mediate M2 macrophage polarization by activating the FFAR4-AMPK-PPARα pathway.

Huangqin decoction ameliorates DSS-induced ulcerative colitis: Role of gut microbiota and amino acid metabolism, mTOR pathway and intestinal epithelial barrier.

BACKGROUND: The clinical treatment of ulcerative colitis (UC) is limited. A traditional Chinese medicinal formula, Huangqin decoction (HQD), is chronicled in Shang Han Lun and is widely used to ameliorate gastrointestinal disorders, such as UC; however, its mechanism is yet to be clarified. PURPOSE: The present study aimed to investigate the effect of HQD on 7-day colitis induced by 3% dextran sulfate sodium (DSS) in mice and further explore the inhibitory effect of metabolites on DSS-damaged FHC cells. METHODS: The therapeutic efficacy of HQD was evaluated in a well-established DSS-induced colitis mice model. The clinical symptoms were analyzed, and biological samples were collected for microscopic examination, metabolomics, metagenomics, and the evaluation of the epithelial barrier function. The mechanism of metabolites regulated by HQD was evaluated in the DSS-induced FHC cell damage model. The samples were collected to detect the physiological functions of the cells. RESULTS: HQD suppressed the inflammation of DSS-induced colitis in vivo, attenuated DSS-induced clinical manifestations, reversed colon length reduction, and reduced histological injury. After HQD treatment, the DSS-induced gut dysbiosis was modulated, and the gut microbiota achieved a new equilibrium state. In addition, HQD activated the mTOR signaling pathway by upregulating amino acid metabolism. Significant phosphorylation of S6 and 4E-BP1 ameliorated intestinal epithelial barrier dysfunction. Moreover, HQD-regulated metabolites protected the epithelial barrier integrity by inhibiting DSS-induced apoptosis of FHC cells and regulating the proteins affecting apoptosis and cell-cell junction. CONCLUSIONS: These findings indicated that the mechanism of HQD was related to regulating the gut microbiota and amino acid metabolism, activating the mTOR signaling pathway, and protecting the intestinal mucosal barrier integrity.

Effects of Huangqin Decoction on ulcerative colitis by targeting estrogen receptor alpha and ameliorating endothelial dysfunction based on system pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: Huangqin Decoction (HQD), a traditional Chinese medicinal (TCM) formula chronicled in Shang Han Lun, has been used to treat gastrointestinal diseases for nearly 1800 years. OBJECTIVE: To investigate the effects and underlying mechanisms of HQD on ulcerative colitis (UC). METHODS: The bioactive compounds in HQD were obtained from the traditional Chinese medicine systems pharmacology database. Then, the HQD and UC-related targets were analyzed by establishing HQD-Compounds-Targets (H-C-T) and protein-protein interaction (PPI) networks. Enrichment analysis was used for further study. The candidate targets for the effects of HQD on UC were validated using a dextran sulfate sodium-induced UC mouse experiment. RESULTS: The results showed that 51 key targets were gained by matching 284 HQD-related targets and 837 UC-related targets. Combined with H-C-T and PPI network analyses, the key targets were divided into endothelial growth, inflammation and signal transcription-related targets. Further experimental validation showed that HQD targeted estrogen receptor alpha (ESR1) and endothelial growth factor receptors to relieve endothelial dysfunction, thereby improving intestinal barrier function. The expression of inflammatory cytokines and signal transducers was suppressed by HQD treatment and inflammation was inhibited. CONCLUSIONS: HQD may acts on UC via the regulation of targets and pathways related to improving the intestinal mucosal barrier and ameliorating endothelial dysfunction. Additionally, ERS1 may be a new target to explore the mechanisms of UC.

Patchouli Oil Attenuates High Fat Diet-induced Non-alcoholic Hepatic Steatosis.

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide. Nevertheless, no first-line therapy exists. Hepatic steatosis is the earliest stage of NAFLD, which is characterized by an accumulation of hepatic lipids. Patchouli oil (PO), which is isolated from the well-known Chinese herb named Pogostemon cablin (Blanco) Benth. (Lamiaceae), inhibits hepatic lipid accumulation effectively. However, its potential ability for the treatment of NAFLD had not been reported before. Thus, the objective of this study was to investigate the effectiveness of PO against hepatic steatosis and its underlying mechanisms. We used a high fat diet (HFD)-induced hepatic steatosis model of rats to estimate the effect of PO against NAFLD. Hematoxylin-eosin and oil red O staining were used to analyze the hepatic histopathological changes. ELISA, RT-qPCR, and Western blotting analysis were applied to evaluate the parameters for hepatic steatosis. Our results showed that PO significantly attenuated the lipid profiles and the serum enzymes, evidenced by quantitative and histopathological analyses. It also markedly down-regulated the expression of sterol regulatory element-binding protein 1 (SREPB-1c) with its downstream factors in de novo lipogenesis. And, likewise, in lipid export by very low-density lipoproteins (VLDL), related molecules were dramatically improved. Furthermore, PO observably normalized the aberrant peroxisome proliferator-activated receptor α (PPAR-α) signal in fatty acids oxidation. In conclusion, PO exerted a preventing effect against HFD-induced steatosis and might be due to decrease de novo lipogenesis, promote export of lipids, as well as owing to improve fatty acids oxidation.

Anti-Inflammatory Effects of Huangqin Decoction on Dextran Sulfate Sodium-Induced Ulcerative Colitis in Mice Through Regulation of the Gut Microbiota and Suppression of the Ras-PI3K-Akt-HIF-1α and NF-κB Pathways.

OBJECTIVE: Huangqin decoction (HQD), a classical traditional Chinese medicinal formula, has been commonly used to treat gastrointestinal diseases for thousands of years. We investigated the anti-inflammatory effects and underlying mechanisms of HQD on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). METHODS: Experimental mice were given 3% DSS, and HQD (2.275, 4.55, and 9.1 g/kg), or mesalazine (ME, 200 mg/kg) orally for 7 days. Body weight loss, disease activity index (DAI), colon length, histology, and levels of inflammatory cytokines were measured to evaluate the effects of HQD on colitis. The effects of HQD on the Ras-phosphoinositide-3-kinase (PI3K)-Akt-hypoxia inducible factor 1 alpha (HIF-1α) and nuclear factor-kappa B (NF-κB) pathways were evaluated by Western blot analysis. In addition, the gut microbiota was characterized using high-throughput Illumina MiSeq sequencing. RESULTS: The results showed that HQD significantly reduced the body weight loss, ameliorated DAI, restored colon length, and improved the intestinal epithelial cell barrier in mice with DSS-induced colitis. The messenger RNA (mRNA) expression levels of inflammatory mediators were decreased following HQD treatment. Furthermore, the Ras-PI3K-Akt-HIF-1α and NF-κB pathways were significantly inhibited by HQD. Finally, treatment with HQD resulted in recovery of gut microbiota diversity. CONCLUSIONS: HQD ameliorates DSS-induced colitis through regulation of the gut microbiota, and suppression of Ras-PI3K-Akt-HIF-1α and NF-κB pathways. Our results suggested that HQD may be a potential candidate for treatment of UC.