Effect of Wumeiwan on cytokines TNF-alpha, IL-6, IL-8, IL-10 and expression of NF-kappaBp65 in rats with ulcerative colitis. ACTA ACUST UNITED AC. 2009;29:650-654. [PMID: 19821103 DOI: 10.1007/s11596-009-0523-4]

Combined non-targeted and targeted metabolomics reveals the mechanism of delaying aging of Ginseng fibrous root

Background: The fibrous root of ginseng (GFR) is the dried thin branch root or whisker root of Ginseng (Panax ginseng C. A. Mey). It is known for its properties such as tonifying qi, producing body fluid, and quenching thirst. Clinically, it is used to treat conditions such as cough, hemoptysis, thirst, stomach deficiency, and vomiting. While GFR and Ginseng share similar metabolites, they differ in their metabolites ratios and efficacy. Furthermore, the specific role of GFR in protecting the body remains unclear. Methods: We employed ultra-high performance liquid chromatography-triple quadrupole mass spectrometry to examine alterations in brain neurotransmitters and elucidate the impact of GFR on the central nervous system. Additionally, we analyzed the serum and brain metabolic profiles of rats using ultra-high performance liquid chromatography-quadrupole-orbitrap mass spectrometry to discern the effect and underlying mechanism of GFR in delaying aging in naturally aged rats. Results: The findings of the serum biochemical indicators indicate that the intervention of GFR can enhance cardiovascular, oxidative stress, and energy metabolism related indicators in naturally aging rats. Research on brain neurotransmitters suggests that GFR can augment physiological functions such as learning and memory, while also inhibiting central nervous system excitation to a certain degree by maintaining the equilibrium of central neurotransmitters in aged individuals. Twenty-four abnormal metabolites in serum and seventeen abnormal metabolites in brain could be used as potential biomarkers and were involved in multiple metabolic pathways. Among them, in the brain metabolic pathways, alanine, aspartate and glutamate metabolism, arginine and proline metabolism, histidine metabolism, and tyrosine metabolism were closely related to central neurotransmitters. Butanoate metabolism improves energy supply for life activities in the aging body. Cysteine and methionine metabolism contributes to the production of glutathione and taurine and played an antioxidant role. In serum, the regulation of glycerophospholipid metabolism pathway and proline metabolism demonstrated the antioxidant capacity of GFR decoction. Conclution: In summary, GFR plays a role in delaying aging by regulating central neurotransmitters, cardiovascular function, oxidative stress, energy metabolism, and other aspects of the aging body, which lays a foundation for the application of GFR.

Pharmacological Mechanism of Mume Fructus in the Treatment of Triple-Negative Breast Cancer Based on Network Pharmacology

Our study aims to find the relevant mechanism of Mume Fructus in the treatment of triple-negative breast cancer (TNBC) by network pharmacology analysis and experimental validation. The effective compounds of Mume Fructus and TNBC-related target genes were imported into Cytoscape to construct a Mume Fructus-effective compounds-disease target network. The common targets of Mume Fructus and TNBC were determined by drawing Venn diagrams. Then, the intersection targets were transferred to the STRING database to construct a protein-protein interaction (PPI) network. To investigate the mechanism of Mume Fructus in treatment of TNBC, breast cancer cell (MDA-MB-231) was treated with Mume Fructus and/or transfected with small interference RNA-PKM2(siPKM2). CCK-8 assay, cell clonal formation assay, transwell, flow cytometry, qRT-PCR, and western blotting were performed. Eight effective compounds and 145 target genes were obtained, and the Mume Fructus- effective compounds-disease target network was constructed. Then through the analysis of the PPI network, we obtained 10 hub genes including JUN, MAPK1, RELA, AKT1, FOS, ESR1, IL6, MAPK8, RXRA, and MYC. KEGG enrichment analysis showed that JUN, MAPK1, RELA, FOS, ESR1, IL6, MAPK8, and RXRA were enriched in the Th17 cell differentiation signaling pathway. Loss of PKM2 and Mume Fructus both inhibited the malignant phenotype of MDA-MB-231 cells. And siPKM2 further aggravated the Mume Fructus inhibition of malignancy of breast cancer cells. Network pharmacology analysis suggests that Mume Fructus has multiple therapeutic targets for TNBC and may play a therapeutic role by modulating the immune microenvironment of breast cancer.

Ameliorating effects of Acacia arabica and Ocimum basilicum on acetic acid-induced ulcerative colitis model through mitigation of inflammation and oxidative stress

Introduction

Ulcerative colitis (UC) is a chronic recurrent inflammatory disease of the large intestine and rectum. The disease is characterized by oxidative stress and severe inflammation. Research has shown the anti-oxidative and anti-inflammatory effects induced by consuming the Acacia arabia and Ocimum basilicum. The present study aimed to evaluate the effect of treatment with O. basilicum together with A. arabica on healing, inflammation, and oxidative stress in the course of experimental colitis in rats.

Methods

A total number of 50 male rats were selected and randomly assigned to five groups of 10 rats each. Colitis was induced in rats by enemas with a 4 % acetic acid solution. Four days after the colitis induction, the rats were orally treated for the next 4 days with saline or a combination of A. arabica and O. basilicum (1000 mg/kg) or sulfasalazine (100 mg/kg).

Results

Acetic acid-induced colitis increased the colon's macroscopic and histopathological damage scores; increased colon levels of MDA (Malondialdehyde), MPO (Myeloperoxidase), TNF-α (Tissue necrosis factor α), IL6 (Interleukin 6), and IL17 (Interleukin 17); and decreased SOD (Superoxide Dismutase), GPx (Glutathione Peroxidase), and IL10 (Interleukin 10) levels in the treated rats compared with the control group (P < 0.001). Overall, a combination of A. arabica and O. basilicum reduced macroscopic and histopathological damage scores (P < 0.01) of the colon, and MDA, MPO, TNF-α, IL6 (P < 0.001), and IL17 (P < 0.01) levels of the colon. Furthermore, it increased SOD, GPx, and IL10 levels compared to the colitis group (P < 0.01).

Conclusion

A. arabica and O. basilicum have improving effects on UC by reducing inflammation and oxidative stress.

Natural Herbal Remedy Wumei Decoction Ameliorates Intestinal Mucosal Inflammation by Inhibiting Th1/Th17 Cell Differentiation and Maintaining Microbial Homeostasis

BACKGROUND

Evidence has shown that the traditional Chinese herbal medicine Wumei decoction (WMD) has a protective effect on ulcerative colitis. Here, we studied the anti-inflammatory effects and potential mechanisms of WMD on chronic colitis in mice.

METHODS

A dextran sulfate sodium (DSS)-induced chronic colitis model and CD45RBhighCD4+ T cell transfer model were established in mice. Body weight, Disease Activity Index, and colon length were assessed, and histopathology was confirmed by hematoxylin and eosin staining. Colon tissue samples were collected to detect the frequencies of various immune cells, expression of cytokines, and tight junction-related proteins using flow cytometry, quantitative real-time polymerase chain reaction, and enzyme-linked immunosorbent assay, respectively. 16S ribosomal DNA sequencing was performed to distinguish differential microbiota of fecal samples.

RESULTS

Severe chronic colitis was observed in mice after DSS exposure and in Rag1-/- mice reconstituted with CD45RBhighCD4+ T cells, as manifested by weight loss, hematochezia, and shortening and thickening of the colon, which were reversed by WMD treatment. WMD markedly suppressed intestinal mucosal CD4+ T cell differentiation and the secretion of proinflammatory cytokines (eg, tumor necrosis factor α, interleukin-1β, interferon γ, and IL-17A) by flow cytometry, quantitative real-time polymerase chain reaction, and enzyme-linked immunosorbent assay, respectively. Moreover, WMD promoted the expression of occludin, zonula occludens-1, and E-cadherin, thereby maintaining the epithelial barrier function. Additionally, 16S ribosomal DNA sequencing revealed that WMD regulated the dysbiosis of gut microbiota in CD45RBhighCD4+ T cell-reconstituted Rag1-/- mice, evidenced by an increase of Allobaculum and Bacteroides and a decrease of Ileibacterium.

CONCLUSIONS

WMD ameliorates chronic colitis in mice induced by DSS or reconstituted with CD45RBhighCD4+ T cells through suppressing Th1/Th17 cell differentiation and the secretion of proinflammatory cytokines, maintaining epithelial barrier function, and improving the dysbiosis.

Wu-Mei-Wan ameliorates chronic colitis-associated intestinal fibrosis through inhibiting fibroblast activation

ETHNOPHARMACOLOGICAL RELEVANCE

Wu-Mei-Wan (WMW), a classic traditional Chinese herb medicine, is one of the most important formulations to treat digestive diseases from ancient times to the present. Previous study showed that WMW has satisfactory curative effects on experimental colitis, which motivating the application of WMW on colitis-associated complications.

AIM OF THE STUDY

Intestinal fibrosis is usually considered to be a common complication of inflammatory bowel disease (IBD), particularly Crohn's disease (CD). Currently, no effective preventive measures or medical therapies are available for that. This work was designed to evaluate the effect and related mechanism of WMW on chronic colitis-associated intestinal fibrosis mice model.

MATERIALS AND METHODS

The chronic colitis-associated intestinal fibrosis mice model was established by weekly intrarectal injection of 2,4,6-trinitrobenzene sulfonic acid (TNBS). The mice survival rate, disease activity index (DAI), colon length and histological score were examined to assess the therapeutic effect of WMW. Masson's trichrome staining, hydroxyproline assay, immunohistochemical staining and western blot analysis were used to evaluate fibrosis level. Colon inflammation was determined by ELISA and immunofluorescence staining. Immunofluorescence staining was used to evaluate fibroblasts proliferation and epithelial to mesenchymal transition (EMT), and the expression of key molecules in fibrosis was analyzed by western blot.

RESULTS

Here we showed that WMW alleviates chronic colitis with improved survival rate, DAI, colon length and histological score. WMW inhibited the progression of intestinal fibrosis, decreased the expression of various fibrosis markers, such as α-SMA, collagen I, MMP-9 and fibronectin. In addition, WMW treatment reduced cytokines IL-6 and IFN-γ, and downregulated proinflammatory NF-κBp65 and STAT3 signaling pathways. Importantly, administration of WMW led to the inhibition of colon fibroblast proliferation and EMT, which are important mediators during fibrosis. Several key profibrotic pathways, including TGF-β/Smad and Wnt/β-catenin pathways, were downregulated by WMW treatment.

CONCLUSION

Our work demonstrated that WMW can prevent intestinal fibrosis and the mechanisms involved may be related to the inhibition of colon fibroblasts activation.

Targeting NF-κB pathway for treating ulcerative colitis: comprehensive regulatory characteristics of Chinese medicines

Nuclear factor-kappa B (NF-κB) is a kind of multi-functional nuclear transcription factor involved in regulating gene transcription to influence pathological evolution of inflammatory and immune diseases. Numerous literature evidence that NF-κB pathway plays an essential role in pathogenic development of ulcerative colitis (UC). UC is a chronic non-specific inflammatory bowel disease, and until now, therapeutic agents for UC including aminosalicylates, corticosteroids and immune inhibitors still cannot exert satisfied effects on patients. In recent years, Chinese medicines suggest the advantages of alleviating symptoms and signs, decreasing side-effects and recurrence, whose one of mechanisms is related to regulation of NF-κB pathway. In this review, we categorize Chinese medicines according to their traditional therapeutic functions, and summarize the characteristics of Chinese medicines targeting NF-κB pathway in UC treatment. It indicates that 85 kinds of Chinese medicines’ compounds and formulae can directly act on NF-κBp65; while 58 Chinese medicines’ ingredients and formulae indirectly suppress NF-κBp65 by regulation of its upstream or other related pathways. Moreover, by the analysis of Chinese medicines’ category based on their traditional functions, we conclude the category of dampness-drying and detoxificating medicine targeting NF-κB pathway accounts for primary status for amelioration of UC. Simultaneously, this review also contributes to the choices of Chinese medicine category and provides curative potential of Chinese medicines for clinical UC treatment.

Gliclazide attenuates acetic acid-induced colitis via the modulation of PPARγ, NF-κB and MAPK signaling pathways

Ulcerative Colitis is a universal autoimmune disease with high incidence rates worldwide. It is characterized by the existence of many other concurrent immune-associated ailments, including diabetes. The used strategies for the management of this highly costing and complicated disease face great challenges. Therefore, the urge for new medication with fewer side effects and high efficacy is growing. The peroxisome proliferator-activated receptor-gamma (PPARγ) and nuclear factor Kappa-B (NF-κB) can be considered as crucial targets for the treatment of ulcerative colitis. Several studies reported the antioxidants, anti-inflammatory, and antiapoptotic actions of gliclazide and evaluated its cardioprotective and renoprotective effects. However, its impact on ulcerative colitis has never been investigated. This study delineated the effect of gliclazide administration on ulcerative colitis induced by acetic acid in rats and the underlying molecular mechanisms. Gliclazide (10 mg/kg; p.o) prominently decreased colon tissue injury as assessed by the histopathological analysis as well as myeloperoxidase, and intercellular adhesion molecule-1 levels. Gliclazide significantly alleviated the proinflammatory mediator, IL-6, promoted the anti-inflammatory cytokine, IL-10 and, withheld oxidative stress in the injured colon tissues. The protective effect of gliclazide was mediated through the upregulation of PPARγ and downregulation of NF-κB expression. The diminution of ulcerative colitis was also accompanied by an inhibition of the elevated activity and expression of mitogen-activated protein kinases and caspase-3 as assessed by Western blot and immunohistochemistry, respectively. Our findings spotlight, for the first time, the potential of the antidiabetic agent, gliclazide, to attenuate the experimentally induced ulcerative colitis. Therefore, gliclazide might be a propitious agent for the management of ulcerative colitis in diabetic patients.

Qing Chang Hua Shi granule ameliorate inflammation in experimental rats and cell model of ulcerative colitis through MEK/ERK signaling pathway

Ulcerative colitis (UC), a bowel disease with significant morbidity, is associated with inflammation. In this study, the effect of Qingchang Huashi granule (QCHS) on UC and its underlying mechanisms were explored using both animal and cell culture experiments. A rat UC model was induced with trinitro-benzene-sulfonic acid (TNBS), concentrations of the cytokines IL-1α, IL-6, IL-8, IL-1β, and TNF-α were significantly up-regulated and the concentrations of IL-4, IL-10, and IL-13 were significantly down-regulated compared with the control group (P < 0.05). In contrast, the QCHS and salicylazosulfapyridine (SASP) groups reversed these modulations (P < 0.05). A UC cell model in HT-29 cells was generated using TNF-α combined with lipopolysaccharide treatment. Cells treated with QCHS were used to investigate the possible mechanisms. The expression of apoptosis-related proteins, including Bax/Bcl-2, caspase-3, caspase-9, Fas/Fas-L, and Rafl in the QCHS and SASP groups, were significantly lower than that in the control group in both animal and cell experiments (P < 0.05). In addition, the in vitro results indicate changes in these indicators mediate the MEK/ERK signaling pathways via SGK1. Our results suggested that QCHS could be beneficial in preventing UC progression as an alternative drug for UC treatment.

Bone marrow mesenchymal stem cells repair colonic vascular endothelium in rats with ulcerative colitis

AIM: To investigate whether bone marrow mesenchymal stem cells (MSCs) can repair colonic vascular endothelium in rats with ulcerative colitis (UC).

METHODS: Monocytes were purified from bone marrow, amplified and identified as MSCs in vitro. Thirty female Wistar rats were randomly and equally divided into three groups: a normal control, a model group and a MSC group. Colitis was induced with trinitro-benzene-sulfonic acid in rats of the model and MSC groups. Rats of the MSC group were injected with 1 mL of MSC suspension via the tail vein, while the rats of the normal control group and model group were injected with equal volume of normal saline. After two weeks, colon tissue samples were analyzed for histopathology, and serial sections of the colon tissue were made for determining the distribution of Y chromosome and CD34 double positive cells. The protein expression of CD34 was detected by immunohistochemisty. The mRNA expression of CD34 was determined by RT-PCR. The contents of interleukin-6 (IL-6) and interleukin-10 (IL-10) in colon tissue were determined by ELISA.

RESULTS: Y chromosome and CD34 double positive cells could be seen in colon tissue of rats injected with MSCs. Compared to the normal control group, the expression of CD34 and IL-6 was increased (1.629 ± 0.067 vs 1.000 ± 0.113, P < 0.05; 238.304 pg/mL ± 0.019 pg/mL vs 81.439 pg/mL ± 0.120 pg/mL, P < 0.01) and the expression of IL-10 was decreased (87.531 pg/mL ± 0.101 pg/mL vs 289.413 pg/mL ± 0.039 pg/mL, P < 0.01) in the model group. Compared to the model group, the expression of CD34 and IL-10 was increased (2.502 ± 0.189 vs 1.629 ± 0.067, P < 0.05; 158.185 pg/mL ± 0.033 pg/mL vs 87.531 pg/mL ± 0.115 pg/mL, P < 0.01) and the expression of IL-6 was decreased (160.95 pg/mL ± 0.116 pg/mL vs 238.304 pg/mL ± 0.109 pg/mL, P < 0.01) in the MSC group.

CONCLUSION: MSCs may exert a therapeutic effect on colitis by differentiating into vascular cell endothelial cells and inhibiting inflammation.

Ginseng in traditional herbal prescriptions

Panax ginseng Meyer has been widely used as a tonic in traditional Korean, Chinese, and Japanese herbal medicines and in Western herbal preparations for thousands of years. In the past, ginseng was very rare and was considered to have mysterious powers. Today, the efficacy of drugs must be tested through well-designed clinical trials or meta-analyses, and ginseng is no exception. In the present review, we discuss the functions of ginseng described in historical documents and describe how these functions are taken into account in herbal prescriptions. We also discuss the findings of experimental pharmacological research on the functions of ginseng in ginseng-containing prescriptions and how these prescriptions have been applied in modern therapeutic interventions. The present review on the functions of ginseng in traditional prescriptions helps to demystify ginseng and, as a result, may contribute to expanding the use of ginseng or ginseng-containing prescriptions.

Wumeiwan treatment alters the expression of delta-opioid receptor, β-arrestin 1 and Bcl-2 in the spleen tissue of rats with ulcerative colitis

AIM: To investigate the effect of Wumeiwan treatment on the expression of delta-opioid receptor, β-arrestin 1 and Bcl-2 in the spleen tissue of rats with ulcerative colitis.

METHODS: Fifty-six SD rats were randomly devided into a control group, a colitis model group, a mesalazine group and a Wumeiwan group (14 rats in each group). Ulcerative colitis was induced in rats with 2, 4, 6-trinitrobenzenesulfonic acid. Two days after induction of ulcerative colitis, the control group and colitis model group were administered intragastrically with normal saline, while the mesalazine group and Wumeiwan group were intragastrically given mesalazine (50 g/L) and Wumeiwan (0.51 g/L), respectively. All rats were treated for 15 d. Spleen tissue samples were taken to detect the mRNA and protein expression of delta-opioid receptor, β-arrestin 1 and Bcl-2 by quantitative RT-PCR and Western blot.

RESULTS: The relative expression levels of delta-opioid receptor, β-arrestin 1 and Bcl-2 mRNAs and proteins were significantly higher in the colitis model group than in the control group (mRNA: 2.50 ± 0.25 vs 1.11 ± 0.10, 3.27 ± 0.41 vs 1.05 ± 0.06, 2.48 ± 0.43 vs 1.06 ± 0.04; all P < 0.05; protein: 1.04 ± 0.17 vs 0.48 ± 0.08, 1.50 ± 0.15 vs 0.62 ± 0.07, 1.26 ± 0.20 vs 0.76 ± 0.10; all P < 0.05). Treatment with Wumeiwan (mRNAs: 1.54 ± 0.13, 1.54 ± 0.14, 1.57 ± 0.15; proteins: 0.68 ± 0.14, 0.74 ± 0.19 and 0.93 ± 0.11) and mesalazine (mRNAs: 1.52 ± 0.09, 1.63 ± 0.27 and 1.56 ± 0.09; proteins: 0.68 ± 0.17, 0.77 ± 0.15 and 0.96 ± 0.16) significantly decreased the expression of delta-opioid receptor, β-arrestin1 and Bcl-2 mRNAs and proteins compared to the colitis model group (all P < 0.05). There was no significant difference in the expression of these mRNAs and proteins between the Wumeiwan group and the mesalazine group (all P > 0.05).

CONCLUSION: Wumeiwan treatment attenuates ulcerative colitis possibly by significantly decreasing the mRNA and protein expression of delta-opioid receptor, β-arrestin 1 and Bcl-2 in the spleen tissue of rats with ulcerative colitis.

Intervention effect of Compound Sophorae Flavescentis decoction on DOR-β-arrestin1-Bcl-2 signal transduction pathway in rats with ulcerative colitis

AIM: To explore the intervention effect of Compound Sophorae Flavescentis decoction on the DOR-β-arrestin1-Bcl-2 signal transduction pathway in rats with ulcerative colitis.

METHODS: Eighty-four Sprague-Dawley rats were equally and randomly divided into normal control group, model group, mesalazine group, high-, medium-, and low-dose Compound Sophorae Flavescentis decoction groups. Except for the normal control group, ulcerative colitis was induced with trinitrobenzene sulfonic acid (TNBS) in rats of other groups. After induction of ulcerative colitis, bloody stools, mental state and diarrhea were observed and recorded daily. Two rats in the model group were randomly selected and executed on day 3 for observing pathological changes in the colon tissue. Rats in the mesalazine group and Compound Sophorae Flavescentis decoction groups were lavaged with mesalazine solution and Compound Sophorae Flavescentis decoction for 15 d, while those in the normal control group and model group were given equal volume of distilled water for the same duration. On day 16, the remaining rats were executed to detect histopathological changes in the colon tissue and the mRNA and protein expression of DOR, β-arrestin1 and Bcl-2 in the colon tissue by real-time PCR and immunohistochemistry, respectively.

RESULTS: The mRNA and protein expression of DOR, β-arrestin1 and Bcl-2 differed significantly among each group (P < 0.05). Compared to the normal control group, the mRNA and protein expression of DOR, β-arrestin1 and Bcl-2 protein was significantly increased (24.11 ± 12.61 vs 11.88 ± 5.90, 38.90 ± 5.30 vs 14.34 ± 8.97, 23.57 ± 9.96 vs 9.68 ± 3.94, all P < 0.05) in the colon mucosa in the model group. Compared to the model group, the mRNA and protein expression of DOR, β-arrestin1 and Bcl-2 in the colon mucosa was significantly decreased in the mesalazine group and Compound Sophorae Flavescentis decoction groups; however, the mRNA and protein expression of DOR, β-arrestin1 and Bcl-2 did not differ significantly between the mesalazine group and Compound Sophorae Flavescentis decoction groups.

CONCLUSION: The expression of DOR, β-arrestin1 and Bcl-2 is elevated in ulcerative colitis. The DOR-β-arrestin1-Bcl-2 signal transduction pathway may be involved in the pathogenesis of ulcerative colitis, and Compound Sophorae Flavescentis decoction may have a significant therapeutic effect against ulcerative colitis.

Role of β2-adrenoceptor-β-arrestin2-nuclear factor-κB signal transduction pathway and intervention effects of oxymatrine in ulcerative colitis

OBJECTIVE

To investigate the β2-adrenoceptor (β2AR)-β-arrestin2-nuclear factor-κB (NF-κB) signal transduction pathway and the intervention effects of oxymatrine in a rat model of ulcerative colitis.

METHODS

Forty SD rats were randomly divided into four groups, which included the normal control group, the model group, the mesalazine group and the oxymatrine treatment group, with 10 rats per group. Experimental colitis induced with trinitrobenzene sulfonic acid (TNBS) was established in each group except the normal control group. The rats in the oxymatrine treatment group were treated with intramuscular injection of oxymatrine 63 mg/(kg·d) for 15 days and the rats in the mesalazine group were treated with mesalazine solution 0.5 g/(kg·d) by gastric lavage for 15 days. The rats in the normal control group and model group were treated with 3 mL water by gastric lavage for 15 days. Diarrhea and bloody stool were carefully observed. Histological changes in colonic tissue were examined on day 7 in 2 rats per group that were randomly selected. The expression of β2AR, β-arrestin2 and NF-κB p65 in colon tissue and spleen lymphocytes were detected with immunohistochemistry and Western immunoblotting techniques on day 16 after fasting for 24 h. Six rats died of lavage with 2 each in the normal control, the model group and the mesalazine group; and were not included in the analysis.

RESULTS

The rats in the model group suffered from looser stool and bloody purulent stool after modeling. But in the oxymatrine and mesalazine groups, looser stool and bloody purulent stool reduced after treatment. And the colonic wall in the model group was thickened and the colon length shortened. The colon mucosa was congested in multiple areas with edema, erosion, superficial or linear ulcer and scar formation, while the intestinal mucosa injury reduced in the mesalazine and oxymatrine groups (P<0.01). In colonic mucosa and in spleen lymphocytes, compared with the normal control group, the expression of NF-κBp65 were significantly increased (P<0.01) in the model group while the expressions of β 2AR and β-arrestin2 were significantly decreased (P<0.01). Compared with the model group, the expression of NF-κ Bp65 was significantly decreased in the mesalazine group (P<0.01) and oxymatrine treatment group (P<0.01) while the expressions of β2AR and β-arrestin2 were significantly increased (P<0.01). There were no statistically significant differences in the expression of β2AR, β-arrestin2 and NF-κBp65 between the mesalazine group and oxymatrine group (P>0.05).

CONCLUSIONS

The β2AR-β-arrestin2-NF-κB signal transduction pathway participated in the pathologic course of ulcerative colitis. Oxymatrine attenuated ulcerative colitis through regulating the β2AR-β-arrestin2-NF-κB signal transduction pathway.

Role of β-arrestins in the pathogenesis of inflammatory bowel disease

β-arrestins, as adaptor proteins involved in G protein-coupled receptor (GPCR)-related signaling, have diverse biological functions and can regulate cell proliferation, survival, apoptosis, motility and gene transcription. β-arrestins regulate several aspects of inflammatory and immune reactions. First, they limit the basal activity of pro-inflammatory transcription factor NF-κB and regulate activation of NF-κB via the Toll-like receptors (TLR)/NF-κB signal pathway. Second, they facilitate T cell activation, suppress the apoptosis of CD4+ T cells, inhibit NK cell-mediated cytotoxicity, and constrain factor-independent survival of macrophages. Finally, β-arrestins influence chemotaxis of immune cells and neutrophil degranulation by regulating desensitization, internalization and signal transduction of various chemokine receptors. The pathogenesis of inflammatory bowel disease (IBD) may be attributed to various genetic abnormalities that result in excessive immune response against the normal intestinal microbe flora. Abnormal immune response is considered to play a pivotal role in the development of IBD. The role of β-arrestins in regulating immune response involved in intestinal mucosal inflammation in IBD implies that they may participate in the pathogenesis of IBD.

Oxymatrine attenuates ulcerative colitis by modulating the β2AR-β-arrestin2-NF-κB signaling pathway in rats

AIM: To investigate whether the β2-adrenoceptor (β2AR)-β-arrestin2-NF-κB signaling pathway mediates the therapeutic effects of oxymatrine on ulcerative colitis in rats.

METHODS: Forty Sprague-Dawley rats were randomly and equally divided into four groups: normal control group, model group, mesalazine group and oxymatrine group. Experiment colitis was induced with TNBS in rats in each group except the normal control group. The rats in the oxymatrine group were intramuscularly injected with oxymatrine injection for 15 d, while those in the mesalazine group were lavaged with 3 mL mesalazine solution for the same duration. The rats in the normal control group and model group were lavaged with 3 mL water for 15 d. Diarrhea and bloody stools were carefully observed in experimental rats. Two rats in each group were randomly selected and executed on day 7 for observing colonic histological changes. On day 16, the remaining rats were executed after fasting 24 h to detect the expression of β2AR, β-arrestin2 and NF-κB p65 in colon tissue and splenic lymphocytes by immunohistochemistry and Western blotting, respectively.

RESULTS: Compared with the normal control group, the expression of NF-κB p65 was significantly increased (both P < 0.01) and the expression of β2AR and β-arrestin2 was significantly decreased (both P < 0.01) in colonic mucosa and splenic lymphocytes in the model group. Compared with the model group, the expression of NF-κB p65 was significantly decreased (16.26 ± 5.51 and 18.34 ± 3.34 vs 61.90 ± 17.75, both P < 0.01) and the expression of β2AR and β-arrestin2 was significantly increased in colonic mucosa in the mesalazine group and oxymatrine group (47.27 ± 12.40 and 61.75 ± 10.40 vs 12.20 ± 2.70, both P < 0.01; 70.71 ± 12.84 and 76.14 ± 8.77 vs 16.80 ± 7.17, both P < 0.01). Compared with the model group, the expression of NF-κB p65 was significantly decreased (114.23 ± 11.56 and 145.62 ± 13.05 vs 249.70 ± 18.94, both P < 0.01) and the expression of β2AR and β-arrestin2 was significantly increased in splenic lymphocytes in the mesalazine group and oxymatrine group (1 006.50 ± 226.89 and 1 102.11 ± 297.72 vs 594.97 ± 209.59, both P < 0.01; 189.97 ± 21.12 and 162.04 ± 15.69 vs 111.77 ± 19.43, both P < 0.01).

CONCLUSION: The β2AR-β-arrestin2-NF-κB signaling pathway participates in the pathogenesis of ulcerative colitis in rats. Oxymatrine attenuates ulcerative colitis by regulating the β2AR-β-arrestin2-NF-κB signaling pathway.