Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0009319 (colitis)
 19,384 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

High dose levels of dehydroepiandrosterone and its 7-hydroxylated derivatives have been shown to reduce oxidative stress and inflammatory responses in dextran sodium sulfate (DSS)-induced colitis in rats. Another endogenous steroid, 7beta-hydroxy-epiandrosterone (7beta-hydroxy-EpiA) has been shown to exert neuroprotective effects at much smaller doses. Our aims were to evaluate whether 7beta-hydroxy-EpiA pre-treatment prevents DSS-induced colitis and to determine whether the effects involve changes in anti-inflammatory prostaglandin (PG) D(2) and 15-deoxy-Delta(12,14)-PGJ(2) (15d-PGJ(2)) levels. Rats were administered 0.01, 0.1 and 1mg/kg 7beta-hydroxy-EpiA i.p. once a day for 7 days. Thereafter, colitis was induced by administration of 5% DSS in drinking water for 7 days. Levels of the PGs and the expression of cyclooxygenase (COX-2) and PG synthases were assessed during the course of the experiment. Administration of 7beta-hydroxy-EpiA caused a transient increase in COX-2 and PGE synthase expression within 6-15h and augmented colonic tissue levels of 15d-PGJ(2) levels starting at day 2. Treatment with DSS resulted in shortened colon length, depleted mucus in goblet cells and induced oxidative stress. COX-2 and mPGES-1 synthase expression were enhanced and accompanied by increased PGE(2), D(2) and 15d-PGJ(2) production. Although all dose levels of 7beta-hydroxy-EpiA reduced PGE(2) production, only the lowest dose (0.01mg/kg) of the steroid completely prevented colitis damage and tissue inflammation. 7beta-Hydroxy-EpiA pre-treatment prevents the occurrence of DSS-induced colitis through a shift from PGE(2) to PGD(2) production, associated with an early but transient increase in COX-2 expression and a sustained increase in the production of the anti-inflammatory prostaglandin 15d-PGJ(2).
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PMID:Anti-inflammatory effects and changes in prostaglandin patterns induced by 7beta-hydroxy-epiandrosterone in rats with colitis. 1850 18

A number of clinical studies have shown that non-steroidal anti-inflammatory drugs (NSAIDs) exacerbate inflammatory bowel disease; however the molecular mechanism whereby this occurs remains unclear. NSAIDs inhibit cyclooxygenase (COX), which has subtypes COX-1 and COX-2. In this study, we have examined the effect of various types of NSAIDs on the development of dextran sulfate sodium (DSS)-induced colitis, an animal model of inflammatory bowel disease. The DSS-induced colitis was worsened by administration of non-selective NSAIDs but not by COX-1 or COX-2 selective inhibitors. However, administration of a combination of both COX-1- and COX-2-selective inhibitors exacerbated the colitis. The intestinal level of PGE(2) dramatically decreased in response to administration of COX-1- and COX-2-selective inhibitors, and exogenously administered PGE(2) suppressed the exacerbation of colitis by NSAIDs. The expression of mucin proteins, which protect the intestinal mucosa, was suppressed by non-selective NSAIDs and this expression was restored by PGE(2), both in vivo and in vitro. Intestinal mucosal cell growth was inhibited by non-selective NSAIDs and this cell growth was restored by PGE(2), both in vivo and in vitro. This study provides evidence that inhibition of both COX-1 and COX-2 and the resulting dramatic decrease in the intestinal level of PGE(2) is responsible for NSAID-dependent exacerbation of DSS-induced colitis. Furthermore, expression of mucin proteins and intestinal mucosal cell growth seems to be involved in this exacerbation and its suppression by PGE(2).
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PMID:Inhibition of both COX-1 and COX-2 and resulting decrease in the level of prostaglandins E2 is responsible for non-steroidal anti-inflammatory drug (NSAID)-dependent exacerbation of colitis. 1910 38

Recent reports suggest that cyclooxygenases (COXs) including COX-2 are constitutively expressed, and prostaglandins (PGs) regulate motility and/or contraction in the colon and rectum. This study examines the role of COXs in the regulation of neuromuscular function in longitudinal preparations of isolated rectum and distal colon (Side A, close to the transverse colon; and Side B, close to the rectum) in normal mice and after the induction of colitis by dextran sulfate sodium (DSS). In control rectum, electrical stimulation (ES)-induced contractions were inhibited by atropine and by COX inhibitors, in an independent manner. PGE(2) at 3microM caused a marked contraction, but the secondary response at 20min after the first application was 60% desensitized. In rectum from DSS-treated mice, spontaneous and ES-induced contractions were significantly less intense than in the control preparations, and the response to PGE(2) was abolished but that to 3microM acetylcholine was not. In control distal colon, the responses to PGE(2) in neither side were desensitized by the repeated application. In DSS-treated distal colon, PGE(2) response was impaired in the two regions, and was desensitized on Side B more than Side A. DSS treatment impaired contractions by 40mM KCl in rectum and on Side B but not Side A. DSS treatment increased COX-2 expression in rectum, but not in distal colon. These findings suggest that the induction of colitis by DSS affects ES- and PGE(2)-regulated motility in the order rectum>distal colon close to the rectum>distal colon in mice.
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PMID:Neurogenic contraction of mouse rectum via the cyclooxygenase pathway: Changes of PGE2-induced contraction with dextran sulfate sodium-induced colitis. 1974 62

Accumulating evidence indicates the crucial contribution of chronic inflammation to various types of carcinogenesis, including colon carcinoma associated with ulcerative colitis and asbestosis-induced malignant mesothelioma. Ulcerative colitis-associated colon carcinogenesis can be recapitulated in mice by azoxymethane administration followed by repetitive dextran sulfate sodium ingestion. In the course of this carcinogenesis process, the expression of a macrophage-tropic chemokine, CCL2, was enhanced together with intracolonic massive infiltration of macrophages, which were a major source of cyclooxygenase (COX)-2, a crucial mediator of colon carcinogenesis. Mice deficient in CCL2-specific receptor, CCR2, exhibited less macrophage infiltration and lower tumor numbers with attenuated COX-2 expression. Moreover, CCL2 antagonists decreased intracolonic macrophage infiltration and COX-2 expression, attenuated neovascularization, and eventually reduced the numbers and size of colon tumors, even when given after multiple colon tumors have developed. These observations identify CCL2 as a crucial mediator of the initiation and progression of chronic colitis-associated colon carcinogenesis and suggest that targeting CCL2 may be useful in treating colon cancers, particularly those associated with chronic inflammation.
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PMID:Blockade of a chemokine, CCL2, reduces chronic colitis-associated carcinogenesis in mice. 1977 34

Diversion colitis occurs commonly in the large bowel remnant after diversion of the fecal stream. Several experimental models of colitis have been described, but none examine the inflammatory alterations that can occur in experimentally defunctioned colons. This characterization could be useful in understanding pathophysiological aspects of diversion colitis, and in developing future therapeutic strategies. Thus, we evaluated the temporal inflammatory alterations in the defunctioned colon of rats by analyzing the histological results, infiltrating neutrophils, pro-inflammatory markers such as cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS), and DNA damage in isolated colonocytes. We compared the obtained data with those from hapten-induced colitis. The experimental diversion of the colon fecal stream induces diversion colitis characterized by an early inflammatory process with increased neutrophil infiltrate, and COX-2 and iNOS expression that resembles, in some aspects, the inflammatory characteristics of chemically induced colitis. After acute inflammation resolution, there was an increase in COX-2 and iNOS expression and the presence of lymphoid follicular hyperplasia and ulcerations, suggesting that diversion colitis can be experimentally established and useful for studying different pathophysiological aspects of this condition.
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PMID:Inflammatory alterations in excluded colon in rats: a comparison with chemically induced colitis. 2001 53

Cyclooxygenase-2 (COX-2), a key enzyme of prostanoid biosynthesis, plays an important role in both hereditary and spontaneous colon cancer. Individuals with ulcerative colitis are also at high risk for colorectal cancer. To investigate the role of Cox-2 in colitis-associated colon cancer, we subjected Cox-2 luciferase-knock-in mice and Cox-2-knockout mice to a well-known mouse model of colitis-associated cancer in which animals are treated with a single-azoxymethane (AOM) injection followed by dextran sulfate sodium (DSS) administration. Tumors induced by AOM and DSS expressed significantly higher Cox-2 levels when compared with surrounding areas of colon, as detected both by luciferase reporter gene expression driven from the endogenous Cox-2 promoter and by western blotting of COX-2 protein in Cox-2 luciferase heterozygous knock-in mice. Immunofluorescence revealed that tumor stromal fibroblasts, macrophages and endothelial cells express COX-2 protein. In contrast, little COX-2 expression was observed in myofibroblasts or epithelial cells. Despite a significant elevation of COX-2 expression in AOM/DSS-induced colon tumors in wild-type mice, similar tumors developed in AOM/DSS-treated Cox-2(-/-)- and Cox-1(-/-)-knockout mice. These results indicate that cyclooxygenase-derived prostanoids are not major players in colitis-associated cancer. In contrast, tumor formation induced by multiple injections of AOM (with no DSS-induced colitis) did not occur in Cox-2(-/-)-knockout mice. Our data suggest that the mechanism of colorectal tumor promotion in colitis-associated cancer differs from the mechanism of tumor promotion for hereditary and sporadic colorectal cancer.
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PMID:Tumor formation in a mouse model of colitis-associated colon cancer does not require COX-1 or COX-2 expression. 2006 61

Failed medical therapy is a common problem in inflammatory bowel disease. P-glycoprotein (P-gp), an efflux pump encoded by MDR1 (ABCB1) gene can actively pump drugs out of cells conferring the phenotype of multidrug resistance. Various studies evoked that cyclooxygenase (COX) system may be involved in the regulation of P-gp activity. Since COX-2 isoform is overexpressed in colic inflammatory states, we examined the inhibitory effect of COX-2-inhibitors on P-gp expression and function under COX-2 stimulated conditions mediated by trinitrobenzene sulfonic acid (TNBS) in vitro, in Caco-2 cells, and in TNBS-induced colitis in mice. COX-2 and P-gp expressions were evaluated by real-time PCR and western blot. The activity of P-gp was measured by intracellular accumulation of rhodamine123 (Rho123) in Caco-2 cells and by Rho123 efflux using the intestinal everted loop method in mice. We showed that COX-2 stimulation in Caco-2 cells by 0.1mM TNBS exposure for 24h induced P-gp protein expression and activity. This activation was reversed by simultaneous COX-2-inhibitor treatment. Moreover, this effect was reproduced in vivo, in mice, where an increased P-gp expression and activity were observed 24h post intra-rectal TNBS administration. Induced P-gp expression and activity could be blocked by the oral pre-treatment with indomethacin heptyl ester (IHE) (20mg/kg). Administration of indomethacin heptyl ester had also a protective effect in TNBS-induced colitis. Our observations suggest that the inhibition of P-gp by COX-2-inhibitors could contribute to the improvement of medical response and this finding may have relevance to medical treatment of inflammatory bowel disease patients.
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PMID:Cyclooxygenase-2 inhibitors prevent trinitrobenzene sulfonic acid-induced P-glycoprotein up-regulation in vitro and in vivo. 2036 60

The bis (1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)-decandioate called IAC, is a new non-peptidyl low molecular weight radical scavenger able to give a fast reaction with the majority of radical species involved in the oxidative stress. This intrinsic property might be of particular interest in all the processes where it presents an over production of reactive oxygen/nitrogen species (ROS/RNS) such as inflammation. Indeed, it is well known that systemic inflammatory response is associated with the production of ROS, nitric oxide (NO), which in turn deplete the endogenous GSH, mediating cytotoxicity. It has been shown that IAC through its antioxidant activity, exerted a protective effect in vitro in islets isolated from type-2 diabetic patients, and in vivo in a non-obese diabetic mouse model and in DNBS-induced colitis in rats. The ability of IAC to protect brain from ischemia, suggests a possible use of the compound in broad range of inflammatory- related diseases. It is well known that the use of non steroidal anti-inflammatory drugs (NSAIDs) is associated with a broad spectrum of untoward side-effects such as gastrointestinal ulceration. The major pathogenetic element in the development of these effects is the depletion of prostaglandins (PGs) through inhibition of cyclooxygenase. The evidence that IAC protects gastric mucosa in an animal model of indomethacin-induced ulcer, through local increase of PGE2 levels and antioxidant activity, candidates this compound as a novel, promising, anti-inflammatory compound avoiding the major common untoward side-effects elicited by NSAID's.
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PMID:Effects of the novel non-peptidyl low molecular weight radical scavenger IAC in different models of inflammation: a new perspective in anti- inflammatory therapy. 2085 12

Chrysophanol is a member of the anthraquinone family and has multiple pharmacological effects, but the exact mechanism of the anti-inflammatory effects of chrysophanol has yet to be thoroughly elucidated. In this study, we attempted to determine the effects of chrysophanol on dextran sulfate sodium (DSS)-induced colitis and lipopolysaccharide (LPS)-induced inflammatory responses in mouse peritoneal macrophages. The findings of this study demonstrated that chrysophanol effectively attenuated overall clinical scores as well as various pathological markers of colitis. Additionally, chrysophanol inhibited the production of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6 and the expression of cyclooxygenase (COX)-2 levels induced by LPS. We showed that this anti-inflammatory effect of chrysophanol is through suppression of the activation of NF-kappaB and caspase-1 in LPS-stimulated macrophages. These results provide novel insights into the pharmacological actions of chrysophanol as a potential molecule for use in the treatment of inflammatory diseases.
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PMID:Anti-Inflammatory activity of chrysophanol through the suppression of NF-kappaB/caspase-1 activation in vitro and in vivo. 2087 34

Colorectal cancer is one of the most serious complications of ulcerative colitis (UC), and the risk of UC-associated neoplasia increases as the region and duration of the disease increase. Selective cyclooxygenase (COX)-2 inhibitors effectively diminish carcinogenesis in a murine UC model. However, this may exacerbate colitis. The selective COX-2 inhibitor etodolac is marketed as a racemic mixture of the R- and S-enantiomers. The biochemical and pharmacological effects of etodolac are caused by the S-enantiomer, while the R-enantiomer lacks COX-inhibitory activity. In this study, we evaluated the effect of R-etodolac on colitis-related mouse colon tumorigenesis. The mice received 1,2-dimethlhydrazine (DMH), and then chronic colitis was induced by administration of two cycles of DSS (each cycle: 3% DSS for 7 days followed by distilled water for 14 days). The mice were sacrificed 28 days after the completion of both cycles. Mice were divided into the following groups: group A served as a disease control; group B received a low (2-mg/kg) dose of R-etodolac every 3 days during the entire period; group C received a high (10-mg/kg) dose of R-etodolac on the same schedule as group B; and group D served as a normal control. Administration of R-etodolac decreased the disease activity index during the DSS administration cycle. The mean number of tumors was 17.8, 15.2, 6.0, and 0 in groups A-D, respectively. In group C, R-etodolac significantly suppressed the occurrence of neoplasia (p<0.05). Although R-etodolac treatment did not affect COX-2 expression, it significantly enhanced expression of E-cadherin in both neoplastic lesions and background mucosa (i.e., lesion-free colon). Thus, administration of R-etodolac exerts a suppressive effect on the development of neoplasia in a murine model of DSS-induced colitis without exacerbation of the colitis. These results suggest that R-etodolac could be useful in the prevention of UC-associated neoplasia.
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PMID:R-etodolac induces E-cadherin and suppresses colitis-related mouse colon tumorigenesis. 2104 43


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