Chang'an decoction alleviates endoplasmic reticulum stress by regulating mitofusin 2 to improve colitis.

OBJECTIVE: To evaluate the protective effects of Chang'an decoction (, CAD) on colitis, and investigate the potential mechanisms underlying these effects from the perspectives of endoplasmic reticulum (ER) stress induced by mitofusin 2 (MFN2). METHODS: The composition of CAD was identified by liquid chromatography-mass spectrometry technology. A mice model of dextran sulfate sodium (DSS) induced colitis was established and therapeutic effects of CAD were determined by detecting body weight, disease activity index, colon length and histopathological changes. Then, the expression levels of MFN2, ER stress markers and Nucleotide-binding domain and leucine-rich repeat protein3 (NLRP3) relevant proteins were detected by polymerase chain reaction (PCR), Western blot, immunohistochemistry and immunofluorescence staining. Subsequently, knockdown and overexpression cell model were constructed to further investigate the underlying mechanism of MFN2 mediating ER stress and energy metabolism by PCR, Western blot, electron microscopy and reactive oxygen species (ROS) staining. Finally, inflammatory indicator and tight junction proteins were measured by PCR and immunofluorescence staining to evaluate the protective effects of CAD. RESULTS: Results showed that the indispensable regulatory role of MFN2 in mediating ER stress and mitochondrial damage was involved in the protective effects of CAD on colitis in mice fed with DSS. Network pharmacology analysis also revealed CAD may play a protective effect on colitis by affecting mitochondrial function. In addition, our data also suggested a causative role for MFN2 in the development of inflammatory responses and energy metabolic alterations by constructing a knockdown and overexpression cell model whereby alter proper ER-mitochondria interaction in Caco-2 cells. Furthermore, relative expression analyses of ER stress markers and NLRP3 inflammasome showed the onset of ER stress and activation of NLRP3 inflammasome, which is consistent with the above findings. In contrast, intervention of CAD could improve the mucosal barrier integrity and colonic inflammatory response effectively through inhibiting ER stress response mediated by MFN2. CONCLUSION: CAD could alleviate ER stress by regulating MFN2 to exert therapeutic effects on DSS-induced colitis, which might provide an effective natural therapeutic approach for the treatment of ulcerative colitis.

Efficacy of active ingredients in Qingdai on ulcerative colitis: a network pharmacology-based evaluation.

OBJECTIVE: To elucidate the protective effect of Qingdai (, QD) on ulcerative colitis (UC) by means of and approaches. METHODS: A systems pharmacology analysis was per-formed to predict the active components of QD whereas the putative biological targets of QD against UC were obtained through target fishing, network cons-truction and enrichment analyses. Meanwhile, we examined the ameliorative effect of QD in a mouse model of dextran sulfate sodium (DSS)-induced colitis. During the 10-day experiment, the control and diseased mice were given with oral gavages of QD (1.3 g raw herbs·kg·d) or 5-aminosalicylic acid (5-ASA, 100 mg·kg·d) every day. The underlying pharma-cological mechanisms of QD in UC were determined using polymerase chain reaction tests, histological staining, enzyme-linked immunoassays, and Western blotting analysis. RESULTS: Searching from various network pharmacology databases, 29 compounds were identified in QD. According to the screening criteria suggested by TCMSP (i.e. OB ≥ 30% and DL ≥ 0.18), nine of them were considered the active ingredients that contribute to the ameliorative effects of QD on different mouse models of colitis. Most importantly, the protective effect of QD on DSS-induced colitis was significantly associated with modulations of the expression levels of glycogen synthase kinase 3-ß (Gsk3-ß) and forkhead box p3 (Foxp3), which are widely considered as important regulators of excessive inflammatory responses. CONCLUSIONS: The results of this study provide solid scientific evidence for the use of QD or its core active components in the clinical management of UC.