[The role of anti-TNF therapy in ulcerative colitis]

Anti-TNF-alfa molecules are currently being used to treat ulcerative colitis regarding to the fact that TNF-alpha has an important role in the pathogenesis of IBD. Although these drugs improved the therapy of patients, immunogenicity limits their potential for clinical use. Infliximab and adalimumab are effective for induction and maintenance of remission in outpatients with moderate to severe steroid-refractory ulcerative colitis. Biologics can be a drug of choice for patients with refractory proctitis and refractory pouchitis. In hospitalized patients with steroid-resistant severe ulcerative colitis who are candidates for colectomy, infliximab may be second-line option. Adequate long-term maintenance therapy with anti-TNF is required after rescue therapy for a sustained benefit. Regarding to the known risk for side-effects of anti-TNF drugs especially in patients concomitantly treated with thiopurines it is urgent future research.

[Role of anti-TNF therapy (biologics) in the treatment of chronic inflammatory bowel disease in children]

Inflammatory bowel disease (IBD) is diagnosed already during childhood or adolescence in every fourth patient. Compared to adult population, whereby recent studies show a tendency towards stabilization, incidence rates for children continue to rise. Though many features are shared with adult onset disease, paediatric ulcerative colitis and Crohn's Disease are, both, more aggressive and extensive already at diagnosis, with disease behaviour that changes with time. Therapeutic approaches, therefore, have to be adapted to specific needs of paediatric population. Aim of the article was to formulate guidelines on the role of biologic therapy in the treatment of paediatric onset inflammatory bowel disease, namely on the use of anti-TNF agent infliximab as it is the only biologic drug registrated for use in children with IBD. Recommendations are based on systematic review of the evidence in paediatric patients whenever it was available. However, due to lack of good randomised studies, adult practice was also taken into consideration. Finally, recommendations were dis-cussed on the consensus conference of all experts participating in the development of guidelines for adult and paediatric pa-tients.The recommendations are developed for Crohn's Disease and for Ulcerative Colitis, separately with respect to remission induction and for relapse prevention. Level of evidence is stated and following this procedure, recommendations are graded. Practice points are also provided with the aim to guide clinicians on the ward how to use biologics in the clinical practice. Com-plications of the treatment that are specific for children with inflammatory bowel disease are also addressed. These guidelines and practice points provide a structured guide for the use of anti-TNF therapy in the treatment of Crohn's Disease and Ulcerative Colitis in paediatric patients.

Multicenter case-control study of the risk factors for ulcerative colitis in China

AIM: To evaluate potential risk factors in the development of ulcerative colitis (UC) in China.

METHODS: A total of 1308 patients with UC and 1308 age-matched and sex-matched controls were prospectively studied in China. The UC cases were collected from 17 hospitals in China from April 2007 to April 2010. Uniform questionnaires were designed to investigate risk factors including smoking, appendectomy, stress, socio-economic conditions, nonsteroidal anti-inflammatory drugs (NSAIDs), oral contraceptives, diet, breastfeeding, infections and family sanitary conditions. Group comparisons by each factor were done using simple logistic regression analysis. Conditional logistic regression was used for multivariate analysis.

RESULTS: By univariate analysis, the variables predictive of UC included feeling stress, light and heavy alcoholic drinking, spicy food, sugar consumption and infectious diarrhea, while heavy tea intake and tap water consumption were protective against UC. On multivariate analysis, the protective factor for UC was tap water consumption [odds ratios (OR) = 0.424, 95%CI: 0.302-0.594, P < 0.001]; while the potential risk factors for UC were heavy sugar consumption (OR = 1.632, 95%CI: 1.156-2.305, P < 0.001), spicy food (light intake: OR = 3.329, 95%CI: 2.282-4.857, P < 0.001; heavy intake: OR = 3.979, 95%CI: 2.700-5.863, P < 0.001), and often feeling stress (OR = 1.981, 95%CI: 1.447-2.711, P < 0.001). Other factors, such as smoking habit, appendectomy, breastfeeding, a history of measles, rural or urban residence, education, oral contraceptives, and NSAID use have not been found to have a significant association with the development of UC in the present study.

CONCLUSION: Our study showed tap water consumption was a protective factor for UC, while spicy food, heavy sugar consumption and often feeling stress were risk factors for UC in this Chinese population.

HMPL-004 (Andrographis paniculata extract) prevents development of murine colitis by inhibiting T-cell proliferation and TH1/TH17 responses

BACKGROUND

Extracts of the plant Andrographis paniculata have been used to treat inflammatory diseases in Asian countries. A recent double-blind, placebo-controlled trial of HMPL-004 (A. paniculata extract) has demonstrated its safety and effectiveness for induction of clinical response, remission, and mucosal healing in patients with mild to moderate ulcerative colitis (UC). We aimed to determine if HMPL-004 could prevent the development of T-cell-dependent murine colitis and to define its in vivo mechanism(s) of action.

METHODS

CD(+)4CD45RB(high) T cells were transferred into Rag1(-/-) mice and gavaged daily with HMPL-004 or methyl cellulose (MC). Severity of colitis was evaluated by weight loss, histology, and cytokine expression.

RESULTS

Mice treated with MC developed colitis within 4-7 weeks, as evaluated by weight loss, and severe intestinal inflammation. HMPL-004-treated mice did not lose weight and displayed only very mild intestinal inflammation. Tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, interferon-gamma (IFN-γ), and IL-22 expression were significantly decreased in HMPL-004-treated mice. We observed higher percentages of naïve CD4(+) T cells in the lamina propria of HMPL-004-treated mice. At early timepoints HMPL-004-treated mice have significantly reduced splenic cell counts, reduced CD4(+), and IL-17(+), and IFN-γ T(+) cells. Furthermore, HMPL-004 inhibited the proliferation of CD4 T cells and differentiation into TH1/TH17 cells in vitro.

CONCLUSIONS

HMPL-004 inhibits the development of chronic colitis by affecting early T-cell proliferation, differentiation, and TH(1)/TH(17) responses in a T-cell-driven model of colitis, presenting a unique mechanism of action. Our data suggest that HMPL-004 could be an attractive herbal therapeutic for inflammatory bowel disease.

Oral 5-aminosalicylic acid for maintenance of remission in ulcerative colitis

BACKGROUND

Oral 5-aminosalicylic (5-ASA) preparations were intended to avoid the adverse effects of sulfasalazine (SASP) while maintaining its therapeutic benefits. Previously, it was found that 5-ASA drugs were more effective than placebo but had a statistically significant therapeutic inferiority relative to SASP. This updated review includes more recent studies and evaluates the effectiveness, dose-responsiveness, and safety of 5-ASA preparations used for maintenance of remission in quiescent ulcerative colitis.

OBJECTIVES

The primary objectives were to assess the efficacy, dose-responsiveness and safety of oral 5-ASA compared to placebo, SASP, or 5-ASA comparators for maintenance of remission in quiescent ulcerative colitis. A secondary objective was to compare the efficacy and safety of once daily dosing of oral 5-ASA with conventional (two or three times daily) dosing regimens.

SEARCH METHODS

A literature search for relevant studies (inception to January 20, 2012) was performed using MEDLINE, EMBASE and the Cochrane Library. Review articles and conference proceedings were also searched to identify additional studies.

SELECTION CRITERIA

Studies were accepted for analysis if they were randomized controlled trials with a minimum treatment duration of six months. Studies of oral 5-ASA therapy for treatment of patients with quiescent ulcerative colitis compared with placebo, SASP or other 5-ASA formulations were considered for inclusion. Studies that compared once daily 5-ASA treatment with conventional dosing of 5-ASA and 5-ASA dose ranging studies were also considered for inclusion.

DATA COLLECTION AND ANALYSIS

The primary outcome was the failure to maintain clinical or endoscopic remission. Secondary outcomes included adherence, adverse events, withdrawals due to adverse events, and withdrawals or exclusions after entry. Trials were separated into five comparison groups: 5-ASA versus placebo, 5-ASA versus sulfasalazine, once daily dosing versus conventional dosing, 5-ASA versus comparator 5-ASA formulation, and 5-ASA dose-ranging. Placebo-controlled trials were subgrouped by dosage. Once daily versus conventional dosing studies were subgrouped by formulation. 5-ASA-controlled trials were subgrouped by common 5-ASA comparators (e.g. Asacol and Salofalk). Dose-ranging studies were subgrouped by 5-ASA formulation. We calculated the relative risk (RR) and 95% confidence intervals (95% CI) for each outcome. Data were analyzed on an intention to treat basis.

MAIN RESULTS

Thirty-eight studies (8127 patients) were included. The majority of included studies were rated as low risk of bias. Eight studies were rated at high risk of bias. Six of these studies were single-blind and two studies were open-label. However, the two open-label studies and four of the single-blind studies utilized investigator performed endoscopy as an endpoint, which may protect against bias. 5-ASA was significantly superior to placebo for maintenance of clinical or endoscopic remission. Forty-one per cent of 5-ASA patients relapsed compared to 58% of placebo patients (7 studies, 1298 patients; RR 0.69, 95% CI 0.62 to 0.77). There was a trend towards greater efficacy with higher doses of 5-ASA with a statistically significant benefit for the 1 to 1.9 g/day (RR 0.65; 95% CI 0.56 to 0.76) and the > 2 g/day subgroups (RR 0.73, 95% CI 0.60 to 0.89). SASP was significantly superior to 5-ASA for maintenance of remission. Forty-eight per cent of 5-ASA patients relapsed compared to 43% of SASP patients (12 studies, 1655 patients; RR 1.14, 95% CI 1.03 to 1.27). A GRADE analysis indicated that the overall quality of the evidence for the primary outcome for the placebo and SASP-controlled studies was high. No statistically significant differences in efficacy or adherence were found between once daily and conventionally dosed 5-ASA. Twenty-nine per cent of once daily patients relapsed over 12 months compared to 31% of conventionally dosed patients (7 studies, 2826 patients; RR 0.92, 95% CI 0.83 to 1.03). Fourteen per cent of patients in the once daily group failed to adhere to their medication regimen compared to 11% of patients in the conventional dosing group (5 studies, 1161 patients; RR 1.21, 95% CI 0.90 to 1.63). There does not appear to be any difference in efficacy among the various 5-ASA formulations. Thirty-eight per cent of patients in the 5-ASA group relapsed compared to 37% of patients in the 5-ASA comparator group (5 studies, 457 patients; RR 1.01, 95% CI 0.80 to 1.28). A pooled analysis of two studies showed no statistically significant difference in efficacy between Balsalazide 6 g and 3 g/day. Twenty-three per cent of patients in the 6 g/day group relapsed compared to 33% of patients in the 3 g/day group (216 patients; RR 0.72; 95% CI 0.46 to 1.13). One study found Balsalazide 4 g to be superior to 2 g/day. Thirty-seven per cent of patients in the 4 g/day Balsalazide group relapsed compared to 55% of patients in the 2 g/day group (133 patients; RR 0.66; 95% CI 0.45 to 0.97). One study found a statistically significant difference between Salofalk granules 3 g and 1.5 g/day. Twenty-five per cent of patients in the Salofalk 3 g/day group relapsed compared to 39% of patients in the 1.5 g/day group (429 patients; RR 0.65; 95% CI 0.49 to 0.86). Common adverse events included flatulence, abdominal pain, nausea, diarrhea, headache, dyspepsia, and nasopharyngitis. There were no statistically significant differences in the incidence of adverse events between 5-ASA and placebo, 5-ASA and SASP, once daily and conventionally dosed 5-ASA, 5-ASA and comparator 5-ASA formulations and 5-ASA dose ranging studies. The trials that compared 5-ASA and SASP may have been biased in favour of SASP because most trials enrolled patients known to be tolerant to SASP which may have minimized SASP-related adverse events.

AUTHORS' CONCLUSIONS

5-ASA was superior to placebo for maintenance therapy in ulcerative colitis. However, 5-ASA had a statistically significant therapeutic inferiority relative to SASP. Oral 5-ASA administered once daily is as effective and safe as conventional dosing for maintenance of remission in quiescent ulcerative colitis. There does not appear to be any difference in efficacy or safety between the various formulations of 5-ASA. Patients with extensive ulcerative colitis or with frequent relapses may benefit from a higher dose of maintenance therapy. High dose therapy appears to be as safe as low dose and is not associated with a higher incidence of adverse events.

A novel murine model of inflammatory bowel disease and inflammation-associated colon cancer with ulcerative colitis-like features

Mutations that increase susceptibility to inflammatory bowel disease (IBD) have been identified in a number of genes in both humans and mice, but the factors that govern how these mutations contribute to IBD pathogenesis and result in phenotypic presentation as ulcerative colitis (UC) or Crohn disease (CD) are not well understood. In this study, mice deficient in both TNF and IL-10 (T/I mice) were found to spontaneously develop severe colitis soon after weaning, without the need for exogenous triggers. Colitis in T/I mice had clinical and histologic features similar to human UC, including a markedly increased risk of developing inflammation-associated colon cancer. Importantly, development of spontaneous colitis in these mice was prevented by antibiotic treatment. Consistent with the known role of Th17-driven inflammation in response to bacteria, T/I mice had elevated serumTh17-type cytokines when they developed spontaneous colitis and after systemic bacterial challenge via NSAID-induced degradation of the mucosal barrier. Although TNF production has been widely considered to be be pathogenic in IBD, these data indicate that the ability to produce normal levels of TNF actually protects against the spontaneous development of colitis in response to intestinal colonization by bacteria. The T/I mouse model will be useful for developing new rationally-based therapies to prevent and/or treat IBD and inflammation-associated colon cancer and may further provide important insights into the pathogenesis of UC in humans.

Evidence-based management of ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory disorder of the gastrointestinal tract, the exact etiology of which remains unknown. The prevalence in the general population is around 0.25%, and the condition represents a considerable financial burden to the health service. The natural history of the condition is one of periods of remission, punctuated by relapses of disease activity. Medical therapy aims to minimise the frequency of these relapses, as well as the need for glucocorticosteroids, which have potentially deleterious effects. In those with acute severe disease, however, glucocorticosteroids are probably effective, as are infliximab and cyclosporine. In those with a mild to moderate flare of disease activity, oral or topical 5-ASAs, or in combination, are more effective than placebo for induction of remission. Doses of oral 5-ASAs in excess of 2g/day appear to lead to higher likelihood of successful remission. Once remission has been achieved, there is evidence to support the use of oral or topical 5-ASAs, and azathioprine to prevent relapse of disease activity. Again, doses of 5-ASA in excess of 2g/day are associated with a lower risk of relapse. Individuals with chronic relapsing and remitting disease activity are difficult to manage, and may require colectomy with ileal pouch anal anastamosis. Granulocyte/monocyte adsorptive apheresis could be of benefit in this setting, but most trials have been conducted in the Far East, so the efficacy in Western UC patients is unclear.

In vitro and in vivo anti-inflammatory activities of Polygonum hydropiper methanol extract

ETHNOPHARMACOLOGICAL RELEVANCE

Polygonum hydropiper L. (Polygonaceae) has been traditionally used to treat various inflammatory diseases such as rheumatoid arthritis. However, no systematic studies on the anti-inflammatory actions of Polygonum hydropiper and its inhibitory mechanisms have been reported. This study is therefore aimed at exploring the anti-inflammatory effects of 99% methanol extracts (Ph-ME) of this plant.

MATERIALS AND METHODS

The effects of Ph-ME on the production of inflammatory mediators in RAW264.7 cells and peritoneal macrophages were investigated. Molecular mechanisms underlying the effects, especially inhibitory effects, were elucidated by analyzing the activation of transcription factors and their upstream signalling, and by evaluating the kinase activities of target enzymes. Additionally, a dextran sulphate sodium (DSS)-induced colitis model was employed to see whether this extract can be used as an orally available drug.

RESULTS

Ph-ME dose-dependently suppressed the release of nitric oxide (NO), tumour necrosis factor (TNF)-α, and prostaglandin (PG)E(2), in RAW264.7 cells and peritoneal macrophages stimulated by lipopolysaccharide (LPS). Ph-ME inhibited mRNA expression of pro-inflammatory genes such as inducible NO synthase (iNOS), cyclooxygenase (COX)-2, and TNF-α by suppressing the activation of nuclear factor (NF)-κB, activator protein (AP-1), and cAMP responsive element binding protein (CREB), and simultaneously inhibited its upstream inflammatory signalling cascades, including cascades involving Syk, Src, and IRAK1. Consistent with these findings, the extract strongly suppressed the kinase activities of Src and Syk. Based on HPLC analysis, quercetin, which inhibits NO and PGE(2) activities, was found as one of the active ingredients in Ph-ME.

CONCLUSION

Ph-ME exerts strong anti-inflammatory activity by suppressing Src/Syk/NF-κB and IRAK/AP-1/CREB pathways, which contribute to its major ethno-pharmacological role as an anti-gastritis remedy.

Fulminant ulcerative colitis despite maximal immunosuppression following liver transplantation: a case report and literature review

Inflammatory Bowel Disease (IBD) is thought to be the result of an overly aggressive immune response to ubiquitous antigens. Immuno -modulation and -suppression is therefore currently the treatment of choice. It was long anticipated that the course of pre-existing IBD should improve after orthotopic liver transplantation (OLT) due to increased immunosuppression. We report the case of a patient who developed acute fulminant colitis despite triple immunosuppression and mesalazine and review the relevant literature.

Potential of Vitex negundo roots in the treatment of ulcerative colitis in mice

CONTEXT

Vitex negundo Linn. (Verbenaceae) is an indigenous tree species in India. This tree species has been of interest to researchers because traditionally its roots are reported in the treatment of ulcer and colic pain.

OBJECTIVE

The present work was undertaken to validate its folk use in the treatment of ulcerative colitis (UC) by using the method of acetic acid-induced colitis in mice.

MATERIALS AND METHODS

Ethanol and aqueous extracts of roots of V. negundo (100 mg/kg) were screened for use in the treatment of UC by the method of acetic acid-induced UC in mice. Macroscopical study of the colon, level of myeloperoxidase (MPO), malondialdehyde (MDA) in colon tissue and blood and histopathology of the colon tissue were studied for the assessment.

RESULTS

Ethanol extract (100 mg/kg) reduced the level of MPO in blood from 355 ± 0.39 to 240 ± 0.36 U/mL and from 385 ± 0.35 to 257 ± 0.36 U/mg in tissue. Similarly, it reduced the level of MDA in blood from 9.40 ± 0.42 to 6.10 ± 0.36 nmol/mL and from 9.38 ± 0.56 to 5.89 ± 0.56 U/mg in tissue. Both the results are comparable with the standard drug, prednisolone (5 mg/kg). This preventive effect was observed by morphological and histopathological study.

DISCUSSION AND CONCLUSION

Results showed that ethanol extract of V. negundo root is effective in the treatment of UC and results are comparable with the standard drug, prednisolone, and thus possessing a great potential in the treatment of UC.

[Surgery for colitis ulcerosa and Crohn's disease in the era of modern medical therapy]

Acute severe ulcerative colitis is a serious condition, which is initially treated with high-dose corticosteroids. Failure to obtain remission should be detected within few days after treatment start, and a decision should be made whether to proceed with either cyclosporine or biological treatment, or to move on to emergency total colectomy with ileostomy. Most patients will later be candidates for a restorative proctocolectomy. Elective indications for restorative proctocolectomy are unresponsiveness to medical treatment, growth retardation in a child/adolescent, and neoplastic transformation. Crohn's disease is increasingly being treated with immunomodulators such as corticosteroids, thiopurines and biologics. These agents play a role both in inflammatory and fistulating diseases, but surgery continues to be important in obstructive and fistulating cases. Recurrences are frequently seen after bowel resection, and cessation of smoking has been shown to lower the risk of recurrence. High risk patients can be treated with thiopurines or biologics as a prophylactic measure to delay or prevent recurrence.

Orally delivered thioketal nanoparticles loaded with TNF-α-siRNA target inflammation and inhibit gene expression in the intestines

Small interfering RNAs (siRNAs) directed against proinflammatory cytokines have the potential to treat numerous diseases associated with intestinal inflammation; however, the side-effects caused by the systemic depletion of cytokines demands that the delivery of cytokine-targeted siRNAs be localized to diseased intestinal tissues. Although various delivery vehicles have been developed to orally deliver therapeutics to intestinal tissue, none of these strategies has demonstrated the ability to protect siRNA from the harsh environment of the gastrointestinal tract and target its delivery to inflamed intestinal tissue. Here, we present a delivery vehicle for siRNA, termed thioketal nanoparticles (TKNs), that can localize orally delivered siRNA to sites of intestinal inflammation, and thus inhibit gene expression in inflamed intestinal tissue. TKNs are formulated from a polymer, poly-(1,4-phenyleneacetone dimethylene thioketal), that degrades selectively in response to reactive oxygen species (ROS). Therefore, when delivered orally, TKNs release siRNA in response to the abnormally high levels of ROS specific to sites of intestinal inflammation. Using a murine model of ulcerative colitis, we demonstrate that orally administered TKNs loaded with siRNA against the proinflammatory cytokine tumour necrosis factor-alpha (TNF-α) diminish TNF-α messenger RNA levels in the colon and protect mice from ulcerative colitis.

Protective effects of selenium and vitamin E combination on experimental colitis in blood plasma and colon of rats

Ulcerative colitis increases oxidative damage accompanied by production of free oxygen radicals. Selenium (Se) and vitamin E are two natural antioxidants. The present study was undertaken to investigate the possible protective role of Se and vitamin E combination in experimental colitis induced by acetic acid (AA) in rats. This study was carried out on three groups, namely the first (control), the second (experimental colitis group, 2 ml 5% acetic acid), and the third groups (2 ml 5% acetic acid, vitamin E (100 mg/kg body weight (bw)) plus Se (0.2 mg/kg bw)). The activities of catalase (CAT), prolidase (PRS), myeloperoxidase (MPO), total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), total thiol (T-SH) were determined in plasma and colon samples. Macroscopic and microscopic damages in colon were increased by AA treatment (p < 0.01 and p < 0.01, respectively), whereas they were decreased by selenium and vitamin E treatment (p < 0.05 and p < 0.01, respectively). The activities of CAT and PRS in the plasma and colon were significantly affected (p < 0.05 and p < 0.01) by treatment of AA, Se, and vitamin E. MPO activity in colon was increased (p < 0.01) by AA treatment and decreased (p < 0.05) by Se and vitamin E administration. The values of TOS and OSI in plasma were increased (p < 0.5) by AA. The TAC and T-SH in colon were decreased (p < 0.05) by AA and increased (p < 0.05) by Se and vitamin E. Based upon these results, Se and vitamin E may play an important role in preventive indication of the oxidative damage associated by acetic acid caused inflammation.

Surveillance strategies in inflammatory bowel disease

Patients with longstanding ulcerative colitis (UC) are at increased risk of developing colorectal cancer (CRC). Although data for CRC risk in Crohn's disease (CD) are limited, it has been suggested that the risk is comparable to UC. Current strategies for the prevention and early detection of cancer in this high risk population are based on the concept of an inflammation-neoplasia-carcinoma sequence. To reduce CRC mortality in inflammatory bowel disease (IBD), colonoscopic surveillance with random and targeted biopsies are recommended to detect early neoplasia. The introduction of novel endoscopic techniques such as conventional or virtual chromoendoscopy to facilitate targeted biopsies or confocal laser endomicroscopy to further characterise suspicious lesions has become increasingly associated with enhanced neoplasia detection. However, there is only indirect evidence that such surveillance strategies are likely to be effective in reducing the risk of death from IBD-associated CRC. Furthermore, new data suggests that surveillance strategies largely based upon disease duration are leading to delayed or missed diagnosis of early CRC in a substantial number of patients. Therefore, current surveillance guidelines seem to lack efficacy and need to be reassessed.

Neutralizing anti-vascular endothelial growth factor (VEGF) antibody reduces severity of experimental ulcerative colitis in rats: direct evidence for the pathogenic role of VEGF

In ulcerative colitis (UC), an increased expression of vascular endothelial growth factor (VEGF) correlates with disease activity, but a causal relationship is unknown. We tested the hypothesis that VEGF plays a mechanistic role in the pathogenesis of experimental UC and that VEGF neutralization may exert therapeutic effect. UC was induced in Sprague-Dawley rats by 6% iodoacetamide given intracolonically. Neutralizing anti-VEGF antibody (50 microg/rat), nonspecific IgG, or saline (0.1 ml/rat) was injected intramuscularly on the 3rd and 5th days after iodoacetamide enema. Rats were euthanized on the 7th day. We examined the extent of macroscopic, histologic, and clinical features of colitis and colonic vascular permeability. Colonic VEGF mRNA and protein expressions increased as early as 0.5 h after iodoacetamide enema and remained elevated in the active phase of colitis. Treatment with anti-VEGF antibody markedly improved the clinical and morphologic features of UC. Colonic lesion area was significantly reduced from 370 +/- 140 or 311 +/- 170 mm(2) in saline- or IgG-treated groups to 122 +/- 57 mm(2) in the anti-VEGF-group (p < 0.05). Increased colonic vascular permeability was decreased by the anti-VEGF antibody (p < 0.05) and the Src inhibitor PP1 [pyrazolopyrimidine, 4-amino-5-(4-methylphenyl)-7-(t-butyl)pyrazolo[3,4-d]-pyrimidine] (p < 0.01). The number of acute and chronic inflammatory cells in the lesion area was significantly reduced in anti-VEGF-treated rats. In the anti-VEGF-treated group, mucosal levels of VEGF, platelet-derived growth factor, and basic fibroblast growth factor were also reduced.

IN CONCLUSION

1) Neutralizing anti-VEGF antibody significantly ameliorates experimental UC in rats in part by reducing excessive vascular permeability and decreasing inflammatory cells infiltration; and 2) VEGF seems to mediate increased colonic vascular permeability in experimental UC via the Src-dependent mechanism.