pregna-4-17-diene-3-16-dione and Colitis

Triggering receptor expressed on myeloid cells 1 (TREM-1)-expressing intestinal macrophages are significantly increased in the colons of patients with inflammatory bowel disease (IBD). We focused here on the effects of guggulsterone on macrophage modulation in colitis as a potential therapeutic molecule in human IBD and explore the underlying mechanisms. Gene expression in macrophages was examined and wound-healing assay using HT-29 cells was performed. Colitis in wild-type and IL-10-, Toll-like receptor 4 (TLR4)-, and myeloid differentiation primary response 88 (MyD88)-deficient mice was induced via the administration of 2,4,6-trinitrobenzene sulfonic acid (TNBS) into the colon. In both in vitro and in vivo experiments, guggulsterone suppressed intestinal inflammation amplified by TREM-1 stimulation, in which the suppression of NF-κB, activating protein-1, and proteasome pathways was involved. In the TNBS-induced colitis model, guggulsterone reduced disease activity index scores and TREM-1 expression, stimulated IL-10 production, and improved survival in wild-type mice. These effects were not observed in IL-10-, TLR4-, and MyD88-deficient mice. Guggulsterone also suppressed M1 polarization, yet induced the M2 phenotype in macrophages from IBD patients as well as from mice. These findings indicate that guggulsterone blocks the hyperactivation of macrophages via TREM-1 suppression and induces M2 polarization via IL-10 mediated by the TLR4 signaling pathway. Furthermore, this study provides a new rationale for the therapeutic potential of guggulsterone in the treatment of IBD. NEW & NOTEWORTHY We found that guggulsterone attenuates triggering receptor expressed on myeloid cells 1 (TREM-1)-mediated hyperactivation of macrophages and polarizes macrophages toward the M2 phenotype. This was mediated by IL-10 and partly Toll-like receptor 4 signaling pathways. Overall, these data support that guggulsterone as a natural plant sterol modulates macrophage phenotypes in colitis, which may be of novel therapeutic importance in inflammatory bowel disease treatment.

Topics: Animals; Anti-Inflammatory Agents; Colitis; Commiphora; HT29 Cells; Humans; Inflammation; Interleukin-10; Intestinal Mucosa; Intestines; Macrophages; Mice; Pregnenediones; Signal Transduction; Toll-Like Receptor 4; Triggering Receptor Expressed on Myeloid Cells-1; Trinitrobenzenesulfonic Acid; Wound Healing

We already showed that the plant sterol guggulsterone has been reported to inhibit nuclear factor-kappaB (NF-kappaB) signaling in intestinal epithelial cells (IECs) and to attenuate dextran sulfate sodium (DSS)-induced colitis. This study investigates the anti-inflammatory effects of novel guggulsterone derivatives on IEC and preventive and therapeutic murine models of DSS-induced colitis. Novel guggulsterone derivates with high lipophilicity were designed and four derivates, including GG-46, GG-50B, GG-52, and GG-53, were synthesized. Two guggulsterone derivatives, GG-50B and GG-52, significantly inhibited the activated NF-kappaB signals and the upregulated expression of interleukin-8 (IL-8) in COLO 205 cells stimulated with tumor necrosis factor-alpha (TNF-alpha). Pretreatment with GG-50B and GG-52 attenuated the increased IkappaB kinase (IKK) and IkappaBalpha phsophorylation induced by TNF-alpha. In preventive and therapeutic models of murine colitis, administration of GG-52 significantly reduced the severity of DSS-induced colitis, as assessed by disease activity index, colon length, and histology. In contrast, GG-50B did not show a significant reduction in the colitis severity. Moreover, the efficacy on attenuating colitis by GG-52 was comparable to that by sulfasalazine or prednisolone. These results indicate that the novel guggulsterone derivative GG-52 blocks NF-kappaB activation in IEC and ameliorates DSS-induced acute murine colitis, which suggests that GG-52 is a potential therapeutic agent for the treatment of inflammatory bowel diseases.

Topics: Animals; Anti-Inflammatory Agents; Cell Line, Tumor; Chemokine CCL2; Colitis; Dextran Sulfate; Epithelial Cells; Humans; I-kappa B Kinase; Interleukin-8; Intestinal Mucosa; Mice; Mice, Inbred C57BL; NF-kappa B; Prednisolone; Pregnenediones; Pregnenes; Sulfasalazine; Trinitrobenzenesulfonic Acid; Tumor Necrosis Factor-alpha

Inflammatory bowel diseases (IBD) are chronic inflammatory and relapsing diseases of the gut that may manifest as either Crohn's disease (CD) or ulcerative colitis (UC). CD and UC are immunologically different diseases characterized by exacerbated Th1 and Th2 response. T-cell resistance against apoptosis contributes to inappropriate T-cell accumulation and the perpetuation of chronic mucosal inflammation. In the present study we have investigated the effect exerted by guggulsterone (GS) a plant derived steroid isolated from the gum resin of the Commiphora mukul tree, in two models of intestinal inflammation induced in mice by trinitro-benzene sulfonic acid (TNBS) and oxazolone. We provided evidence that E-GS protects mice against development of sign and symptoms of colon inflammation. E-GS effectively attenuated the severity of wasting disease and the fecal score and colon inflammation as assessed by measuring the macroscopic- and microscopic-damage scores. Administration Z-GS failed to ameliorate colon inflammation in TNBS-induced colitis and had a partial effect in oxazolone-induced colitis. In vitro, mechanistic studies carried out using CD4+ cells isolated from the intestinal lamina propria demonstrate that GS effectively regulates the function of effector T cells by modulating cell signaling activation pathway caused by CD3/CD28. The net biological effects resulting from exposure to GS includes attenuation of generation of interleukin-2 and -4 and interferon-gamma as well as T cell proliferation. In conclusion, GS is an anti-inflammatory compound with the capacity to prevent and ameliorate T-cell-induced colitis. These data ground the use of GS, a natural cholesterol-lowering agent, in the treatment of chronic inflammatory diseases.

Topics: Animals; Base Sequence; Colitis; Disease Models, Animal; DNA Primers; Immunity, Innate; Inflammatory Bowel Diseases; Mice; Mice, Inbred BALB C; Mice, SCID; Plants; Polymerase Chain Reaction; Pregnenediones

The plant sterol guggulsterone has been shown to have anti-inflammatory properties. It remains unknown, however, whether guggulsterone is effective for the treatment of inflammatory bowel disease (IBD). Therefore, we investigated anti-inflammatory effects of guggulsterone on intestinal epithelial cells (IEC) and on experimental murine colitis models and elucidated its molecular mechanisms.. Human Caco-2 cells and rat non-transformed IEC-18 cells were stimulated with interleukin (IL)-1beta or lipopolysaccharide (LPS) with or without guggulsterone. The effects of guggulsterone on nuclear factor (NF)-kappaB signaling in IEC were examined by intercellular adhesion molecule (ICAM)-1 real-time reverse-transcription polymerase chain reaction, NF-kappaB transcriptional activity assay, Western blotting for IkappaB phosphorylation/degradation, electrophoretic mobility shift assay, and in vitro IkappaB kinase (IKK) assay. For in vivo study, dextran sulfate sodium (DSS)-treated mice were fed with or without guggulsterone. Colitis was quantified by disease activity index and evaluation of macroscopic and microscopic findings. Phosphorylation of IkappaB and IKK in colon mucosa was assessed by Western blotting and immunohistochemistry.. Guggulsterone significantly inhibited LPS- or IL-1beta-induced ICAM-1 gene expression, NF-kappaB transcriptional activity, IkappaB phosphorylation/degradation, and NF-kappaB DNA binding activity in IEC. Moreover, guggulsterone strongly blocked IKK activity. Administration of guggulsterone significantly reduced the severity of DSS-induced murine colitis as assessed by clinical disease activity score, colon length, and histology. Furthermore, tissue upregulation of IkappaB and IKK phosphorylation induced by DSS was attenuated in guggulsterone-treated mice.. Guggulsterone blocks NF-kappaB signaling pathway by targeting IKK complex in IEC and attenuates DSS-induced acute murine colitis, which suggests that guggulsterone could be an attractive therapeutic option in the treatment of IBD.

Topics: Animals; Colitis; DNA; Enterocytes; Female; Humans; I-kappa B Kinase; I-kappa B Proteins; Intercellular Adhesion Molecule-1; Interleukin-1beta; Lipopolysaccharides; Mice; Mice, Inbred C57BL; NF-kappa B; Phosphorylation; Phytosterols; Phytotherapy; Pregnenediones; Rats; RNA, Messenger; Signal Transduction; Transcription, Genetic