Colonic insufflation with carbon monoxide gas inhibits the development of intestinal inflammation in rats.

BACKGROUND: The pathogenesis of inflammatory bowel disease (IBD) is complex, and an effective therapeutic strategy has yet to be established. Recently, carbon monoxide (CO) has been reported to be capable of reducing inflammation by multiple mechanisms. In this study, we evaluated the role of colonic CO insufflation in acute colitis induced by trinitrobenzene sulfonic acid (TNBS) in rats. METHODS: Acute colitis was induced with TNBS in male Wistar rats. Following TNBS administration, the animals were treated daily with 200 ppm of intrarectal CO gas. The distal colon was removed to evaluate various parameters of inflammation, including thiobarbituric acid (TBA)-reactive substances, tissue-associated myeloperoxidase (MPO) activity, and the expression of cytokine-induced neutrophil chemoattractant (CINC)-1 in colonic mucosa 7 days after TNBS administration. RESULTS: The administration of TNBS induced ulceration with surrounding edematous swelling in the colon. In rats treated with CO gas, the colonic ulcer area was smaller than that of air-treated rats 7 days after TNBS administration. The wet colon weight was significantly increased in the TNBS-induced colitis group, which was markedly abrogated by colonic insufflation with CO gas. The increase of MPO activity, TBA-reactive substances, and CINC-1 expression in colonic mucosa were also significantly inhibited by colonic insufflation with CO gas. CONCLUSIONS: Colonic insufflation with CO gas significantly ameliorated TNBS-induced colitis in rats. Clinical application of CO gas to improve colonic inflammatory conditions such as IBD might be useful.

Rebamipide promotes healing of colonic ulceration through enhanced epithelial restitution.

AIM: To investigate the efficacy of rebamipide in a rat model of colitis and restitution of intestinal epithelial cells in vitro. METHODS: Acute colitis was induced with trinitrobenzene sulfonic acid (TNBS) in male Wistar rats. Rats received intrarectal rebamipide treatment daily starting on day 7 and were sacrificed on day 14 after TNBS administration. The distal colon was removed to evaluate the various parameters of inflammation. Moreover, wound healing assays were used to determine the enhanced restitution of rat intestinal epithelial (RIE) cells treated with rebamipide. RESULTS: Intracolonic administration of rebamipide accelerated TNBS-induced ulcer healing. Increases in the wet weight of the colon after TNBS administration were significantly inhibited by rebamipide. The wound assay revealed that rebamipide enhanced the migration of RIE cells through phosphorylation of extracellular signal-regulated kinase (ERK) and activation of Rho kinase. CONCLUSION: Rebamipide enema healed intestinal injury by enhancing restitution of RIE cells, via ERK activation. Rebamipide might be a novel therapeutic approach for inflammatory bowel disease.

Ecabet sodium promotes the healing of trinitrobenzene-sulfonic-acid-induced ulceration by enhanced restitution of intestinal epithelial cells.

BACKGROUND AND AIMS: Ecabet sodium (ES) is a gastric mucosal protective and ulcer-healing agent. Recently enema therapy with ES was found to be effective for the treatment of human ulcerative colitis as well as experimental colitis in an animal model. Whereas ES possesses potential as a novel treatment for ulcerative colitis, its precise mechanism of action remains to be elucidated. In this study, we investigated the therapeutic efficacy of ES in an experimental rat model of colitis, and evaluated the restitution of intestinal epithelial cells treated with ES in vitro. METHODS: Acute colitis was induced with trinitrobenzene sulfonic acid (TNBS) in male Wistar rats. Rats received intrarectal treatment with ES daily starting on day 7 and were sacrificed on day 14 after the administration of TNBS. The distal colon was removed to evaluate various parameters of inflammation. Moreover, wound-healing assays were used to determine the enhanced restitution of rat intestinal epithelial (RIE) cells treated with ES. RESULTS: Intracolonic administration of ES accelerated TNBS-induced ulcer healing. Increases in the wet weight of the colon after TNBS administration were significantly inhibited by ES treatment. The wound assay revealed ES enhancement of the migration of RIE cells migration through the phosphorylation of extracellular signal-regulated kinase. CONCLUSION: Daily administration of an ES enema promoted the healing of intestinal mucosal injury, in part by the enhanced restitution of intestinal epithelial cells via extracellular signal-regulated kinase activation. ES may thus represent a novel therapeutic approach for the treatment of inflammatory bowel disease.

Gene expression profiles of diabetic mice treated with whole body hyperthermia: A high-density DNA microarray analysis.

Previously we have demonstrated that whole body hyperthermia (WBH) improves insulin resistance in diabetic mice. The aim of the present study was to perform a gene expression analysis of the liver and adipose tissue of obesity-induced insulin resistant diabetic mice (db/db mice) after WBH and to define the molecules that play the important role in improvement of insulin resistance by WBH. Male db/db mice were treated with WBH 3 times per week for 12 weeks. Total RNA was extracted from the liver and adipose tissue of db/db mice, and differences in the gene expression profiles among db/+ mice, untreated db/db mice, and WBH-treated db/db mice were investigated using a high-density DNA microarray. WBH directly targets liver and adipose tissue, resulting in modifications in NF-kappaB and IL-6 signalling pathways, as well as lipid metabolism. Although the mechanisms have not yet been completely investigated, we can conclude that WBH may provide a new therapeutic or preventive modality against type 2 diabetes mellitus and metabolic or insulin resistance syndrome through the modification of several signalling pathways.

CV-11974, angiotensin II type I receptor antagonist, reduces the severity of indomethacin-induced rat enteritis.

The aim of the present study was to examine the effect of angiotensin II type I receptor antagonist, CV-11974, on indomethacin-induced small intestinal injury in rats. Single administration of indomethacin provoked severe inflammatory lesions in the small intestine. The levels of thiobarbituric acid-reactive substances (TBARS), myeloperoxidase (MPO) activities and cytokine-induced neutrophil chemoattractant-1 (CINC-1) in the intestinal mucosa significantly increased in the indomethacin-treated group compared with the sham group. In addition, the angiotensin II type I receptor was increased in the small intestine after the administration of indomethacin. The development of intestinal lesions in response to indomethacin was prevented by pretreatment with CV-11974 together with significant suppression of the increased level of TBARS, MPO activities and CINC-1. These results indicate that CV-11974 protected against the small intestinal damage elicited by indomethacin, which suggests that angiotensin II/AT1 receptor interaction is involved in the pathogenesis of the intestinal inflammation associated with oxidative stress.

Antitumor effect of whole body hyperthermia with alpha-galactosylceramide in a subcutaneous tumor model of colon cancer.

AIM: Whole body hyperthermia (WBH) has been used clinically as an adjunct to radio- and chemotherapy in patients with various cancers. Recently, it has been reported that an activation of the immune system has recently been reported as a possible contributor to the therapeutic effects of WBH. Conversely, the glycolipid alpha-galactosylceramide (alpha-GalCer) is recognized by natural killer (NK) T cells together with the monomorphic MHC-like antigen, CD1d, in mice and humans. This study investigated the antitumor effects of WBH combined with alpha-GalCer in a mouse subcutaneous tumor model of colon cancer. METHODS: Colon26 cells were inoculated subcutaneously into male BALB/c mice to establish subcutaneous tumor. Colon26-bearing mice were treated with WBH using far infrared rays three times/week. Rectal temperature was maintained for 60 min at 41 degrees C. In some experimental groups, alpha-GalCer was intraperitoneally injected before WBH. We investigated the therapeutic effects of WBH, alpha-GalCer and combined therapy. RESULTS: (1) Compared with controls, WBH alone resulted in significant inhibition of tumor growth. (2) No inhibitory effect on tumor growth was seen with alpha-GalCer. (3) The combination of WBH and alpha-GalCer showed significant inhibition of tumor growth and prolongation of survival. (4) Serum IFN-gamma increased after 3 h and returned to basal levels by 24 h after alpha-GalCer administration. (5) CTL activity was enhanced following combination therapy with WBH and alpha-GalCer. CONCLUSION: WBH showed antitumor effects in a mouse subcutaneous tumor model of colon cancer. Addition of alpha-GalCer increased the efficacy of WBH, probably via enhancement of immune response.

Whole body hyperthermia improves obesity-induced insulin resistance in diabetic mice.

AIM: In this study, we examined the efficacy of whole body hyperthermia (WBH) on obesity-induced insulin resistance in diabetic mice. METHODS: Male db/db mice were treated with WBH 3 times per week for 12 weeks. The rectal temperature of mice reached 38.0 degrees C 5 min after heating, and was kept at 38.0 degrees C for 30 min. At the end of each week, tail snip glucose levels were determined under fasting conditions. The GLUT-4 gene expression of muscle tissue was analyzed by real-time PCR. RESULTS: (1) WBH-treated db/db mice showed a significant decrease in fasting blood glucose level as compared with untreated db/db mice (p < 0.01). (2) Plasma insulin levels in untreated db/db mice at the age of 10 weeks were significantly increased compared with those of db/+ mice (p < 0.0001). On the other hand, the reduction (31%) in insulin levels in WBH-treated mice indicated improved insulin sensitivity. (3) The ability of WBH to increase insulin sensitivity was further established in glucose tolerance tests and insulin tolerance tests. (4) Urine albumin of db/db mice significantly increased compared with those of db/+ mice at 18 weeks of age (p < 0.001). This increase in urinary albumin was significantly inhibited by WBH (p < 0.01). (5) WBH up-regulated the expression of GLUT4 mRNA in skeletal muscle. CONCLUSION: Although the mechanisms have not yet been completely investigated, WBH may provide a new therapeutic or preventive modality against obesity-related diseases such as T2DM and metabolic or insulin resistance syndrome.

Lansoprazole, a proton pump inhibitor, reduces the severity of indomethacin-induced rat enteritis.

The spread of capsule endoscopy has led to a focus on small intestinal injury induced by non-steroidal anti-inflammatory drugs (NSAIDs). However, it has been proposed that proton pump inhibitors (PPI), a strong anti-secretary agent, have anti-inflammatory action beyond acid suppression. Therefore, we evaluated the biological effects of lansoprazole, a PPI used in the clinical area, in the setting of experimental rat non-steroidal anti-inflammatory drug-induced enteritis. The animals were given indomethacin subcutaneously and the intestinal mucosa was examined 24 h later. Lansoprazole was given subcutaneously just after following indomethacin injection. Single administration of indomethacin at 10 mg/kg provoked severe hemorrhagic lesions in the small intestine, mostly the jejunum and ileum. The levels of thiobarbituric acid-reactive substances (TBARS), the myeloperoxidase (MPO) activity and the content of cytokine-induced neutrophil chemoattractant-1 (CINC-1) in the intestinal mucosa significantly increased in indomethacin-treated groups compared with the sham-operated groups. The development of intestinal lesions in response to indomethacin was dose-dependently prevented by lansoprazole at a dose of 5 mg/kg together with significant suppression of the increased level of TBARS, MPO activities and CINC-1 in the small bowel. Furthermore, the increased CINC-1 mRNA expression after administration of indomethacin was also inhibited by treatment with lansoprazole. These results suggest that lansoprazole administered exogenously prevented the small intestine against indomethacin-induced damage, the action being dependent on its anti-inflammatory and anti-oxidative responses. This evidence supports the theory that PPI have an expanding role beyond acid suppression.

Chemical constituents of Murraya siamensis: three coumarins and their anti-tumor promoting effect.

Isolation and structure elucidation of three coumarins, murrayacoumarins A, B, and C, together with eight known coumarins, from the leaves of Murraya siamensis Craib collected in Thailand are described. Results of a primary screening of inhibitory effects of seven of these compounds on 12-O-tetradecanoylphorbol-13-acetate-induced Epstein-Barr virus early antigen activation in Raji cells are also presented.