Rectal and colonic mesalazine concentration in ulcerative colitis: oral vs. oral plus topical treatment

Intestinal antiinflammatory effect of 5-aminosalicylic acid is dependent on peroxisome proliferator-activated receptor-gamma

5-aminosalicylic acid (5-ASA) is an antiinflammatory drug widely used in the treatment of inflammatory bowel diseases. It is known to inhibit the production of cytokines and inflammatory mediators, but the mechanism underlying the intestinal effects of 5-ASA remains unknown. Based on the common activities of peroxisome proliferator–activated receptor-γ (PPAR-γ) ligands and 5-ASA, we hypothesized that this nuclear receptor mediates 5-ASA therapeutic action. To test this possibility, colitis was induced in heterozygous PPAR-γ^+/− mice and their wild-type littermates, which were then treated with 5-ASA. 5-ASA treatment had a beneficial effect on colitis only in wild-type and not in heterozygous mice. In epithelial cells, 5-ASA increased PPAR-γ expression, promoted its translocation from the cytoplasm to the nucleus, and induced a modification of its conformation permitting the recruitment of coactivators and the activation of a peroxisome-proliferator response element–driven gene. Validation of these results was obtained with organ cultures of human colonic biopsies. These data identify PPAR-γ as a target of 5-ASA underlying antiinflammatory effects in the colon.

Long-term oral plus topical mesalazine in frequently relapsing ulcerative colitis

BACKGROUND

In cross-sectional studies, it was demonstrated that the therapeutic effect of mesalazine is closely related to its mucosal concentration.

AIM

This study was carried out to verify in a longitudinal study if it was possible to improve the clinical course of ulcerative colitis at high risk of recurrence by increasing mucosal mesalazine concentration.

METHODS

Eighteen consecutive ulcerative colitis patients on continuous oral 5-ASA treatment (2.4-3.2 g/day) in clinical remission who had had at least four moderate to severe relapses in the preceding 2 years (referred period) were assigned to assume oral (3.2-4.8 g/day) and topical (4 g/day) mesalazine in order to increase mucosal drug concentration and were followed up for 2 years (study period). The localisation of disease was 12 pancolitis, six left colitis. The number and severity of recurrences, number of visits and endoscopies, courses of steroids and days of hospitalisation were compared with those of the previous 2 years. Rank signed test for paired data was used for statistical analysis.

RESULTS

The total number of recurrences was significantly lower during the study period in comparison with that of referred period (8 versus 80, respectively, p < 0.0001). No courses of steroids or hospitalisation were necessary during study period in comparison with those of referred period (0 versus 33, p < 0.0001; 0 versus 93, p = 0.03, respectively). A total number of 249 visits were done during the referred period and 116 during the study period (p < 0.0001) with a total of 87 endoscopies during referred period and 44 during study period (p < 0.0001).

CONCLUSIONS

The continuous use of topical mesalazine associated with a high oral dosage significantly improves the clinical course of ulcerative colitis patients at high risk of relapse.

Topical delivery of therapeutic agents in the treatment of inflammatory bowel disease

For targeting local and systemic inflammatory processes in inflammatory bowel disease (IBD) therapeutic agents of first choice (e.g. aminosalicylates, corticosteroids) have been developed in special galenic forms to accomplish the topical delivery of the active compounds to the terminal ileum (Crohn's disease) and/or the colon (Crohn's disease and ulcerative colitis). However, it has to be realized that intestinal physiology (e.g. motility, intraluminal pH profiles), extent and pattern of IBD as well as drug disposition demonstrate large interindividual differences resulting in variable clinical response rates between about 35% and 75%. 5-Aminosalicylate (5-AS) can be delivered to the colon either by azo-prodrugs (e.g. sulfasalazine, olsalazine or balsalazide) or by direct rectal administration of 5-AS in form of enemas, foam or suppositories. Such formulations will be only effective in patients with ulcerative colitis (UC). Various slow/controlled release preparations of 5-AS have been developed for oral use. Some of them (e.g. Pentasa, Salofalk) release sufficient 5-AS already in the small bowel which could provide some additional benefit in Crohn's disease (CD). As urinary and faecal recoveries of total 5-AS are similar for all oral formulations, no major clinical differences can be expected. Extent of the disease, profile of adverse effects and patient's acceptance provide some guidance for selection of the particular agent. Rectal installation of several glucocorticosteroids has been employed for many years. More recently scientific and clinical interest has been focused on budesonide which is extensively presystemically metabolized in the intestinal wall and the liver. Therefore, its systemic availability is low (10-15%) independent whether budesonide is administered orally as controlled release formulation in patients with CD or rectally as enema in patients with UC. Numerous pharmacokinetic and clinical studies have documented the anticipated topical delivery and clinical efficacy of this corticosteroid without serious side effects such as cushingoid features. It can be assumed that for any novel therapeutic principle in IBD the approach of topical delivery will be also tried.

Oral mesalazine (5-ASA) treatment may protect against proximal extension of mucosal inflammation in ulcerative proctitis

OBJECTIVES

Studies aimed at establishing which characteristics of patients with ulcerative proctitis could be predictive of the extension of inflammation have failed to provide conclusive results. The aim of the study was to evaluate the prognostic role of clinical and therapeutic parameters in patients with proctitis.

PATIENTS AND METHODS

Case records of 138 patients with ulcerative proctitis were retrospectively evaluated. The following parameters were considered: gender; age at onset of disease; smoking habits; histologic severity of disease at onset; mean number of clinical relapses of disease per year; mean duration of oral and topical mesalazine treatment; and number of topical corticosteroid treatments per year.

RESULTS

Twenty-eight patients were excluded from the analysis for different reasons. During follow-up, inflammation spread proximally in 33 of 110 patients (30%). Patients with extended proctitis showed a significantly higher number of relapses and a shorter duration of oral mesalazine treatment than patients with nonprogressive proctitis (p < 0.001 for both). The multivariate analysis also found that the mean duration of topical mesalazine treatment was longer in patients with extended proctitis.

CONCLUSIONS

Ulcerative proctitis patients with more frequent relapses who need a longer duration of topical therapy are at higher risk of extension of the disease, while a more prolonged oral mesalazine treatment period protects against the proximal spread of rectal inflammation.

Effect of mesalazine, metronidazole and gentamicin on bacterial translocation in experimental colitis

BACKGROUND AND AIM

In inflammatory bowel disease it has been established that enteric microorganisms are present in the final stage of the active inflammatory process. The purpose of the present study was to investigate the effects of mesalazine, and metronidazole-gentamicin combination, on bacterial translocation in an animal colitis model.

METHODS

Fifty rats were stratified into five groups. The control group (group NC) was given only 2 mL saline enema and the remaining four groups were given 2 mL acetic acid enema. Group CC was the diseased control group. The treatment regimens started on the fifth day: mesalazine enema in group MesC, metronidazole-gentamicin in group MGC, and mesalazine + metronidazole + gentamicin in group MesMGC. After death on day 10, 2.5-cm colonic segments from all groups were weighed separately. In all rats, histopathological scoring was done, and samples from feces, blood, liver and spleen underwent microbiological analyses.

RESULTS

For all diseased rats, both mean weight loss and colonic segment weight/bodyweight ratio was significantly higher than that in the sham group. As compared with other groups, body and colonic segment changes as well as histopathological scoring in rats receiving mesalazine enema either solely or in combination with the antibiotics were lower. No bacterial growth was found in the blood, liver and spleen of the rats in the control group while enteric bacteria, mainly Escherichia coli (35%) were the most common bacteria translocated to that in the latter. Antibiotic combination, alone or in combination with mesalazine was effective in reducing the bacterial translocation while mesalazine administration did not properly influence its regression.

CONCLUSIONS

Gram-negative enteric bacteria, predominantly E. coli, was the most common bacteria isolated in bacterial translocation occurring in acetic acid-induced colitis. This trial showed that mesalazine alone did not incorporate the reduction of infectious events, despite its beneficial effect on inflammatory changes in experimental colitis. Metronidazole and gentamicin combination given intraperitoneally was more effective than topical mesalazine in decreasing bacterial translocation.

Co-infection with Chlamydia pneumoniae and Helicobacter pylori results in vascular endothelial dysfunction and enhanced VCAM-1 expression in apoE-knockout mice

BACKGROUND

Upregulation of proinflammatory endothelial cell adhesion molecules and decreased bioactivity of endothelial nitric oxide (NO) are important in the pathogenesis of atherosclerosis. We investigated the effects of co-infection with Chlamydia pneumoniae and Helicobacter pylori on these two events in apoE-KO mice.

METHODS

Thirty-two apoE-KO mice, 8 weeks old, were equally divided into 4 groups. The first 2 groups were infected with either C. pneumoniae or H. pylori, while the 3rd group was infected with both C. pneumoniae and H. pylori. Mice from the 4th group and 4 wild-type mice served as controls. Thoracic and abdominal aortas were harvested after 10 weeks, and staining for vascular cell adhesion molecule-1 (VCAM-1) and intracellular adhesion molecule-1 was analyzed by immunocytochemistry. The endothelial vasomotor responses of thoracic aortas to methacholine were studied in organ chambers in the absence and presence of L-NAME. The plasma levels of nitrate/nitrite were measured.

RESULTS

Staining for VCAM-1 was more intense at the branching sites of aortas from mice with co-infection than in mono-infected or noninfected apoE-KO mice. The relaxation responses to methacholine and the plasma levels of nitrate/nitrite were significantly less in the co-infected group than in the other groups (p < 0.05).

CONCLUSION

Co-infection of apoE-KO mice with C. pneumoniae and H. pylori seems to be associated with impaired bioactivity of endothelial NO and increased expression of VCAM-1 at branching sites. The findings may suggest an additive interaction of these pathogens in atherogenesis.

Rectal tissue, plasma and urine concentrations of mesalazine after single and multiple administrations of 500 mg suppositories to healthy volunteers and ulcerative proctitis patients

OBJECTIVE

Patients with ulcerative proctitis may have rectal mucosal properties different from healthy volunteers. This project compared the pharmacokinetics of rectally administered mesalazine in these two populations.

METHODS

In two separate studies, nine patients with ulcerative proctitis and 16 healthy volunteers received a single 500 mg mesalazine suppository and then 500 mg every 8 h for 5 days. Blood samples were collected for 12 h in healthy volunteers and 30 h in patients, and urine for 24 h in healthy volunteers and 30 h in patients. Rectal biopsies were performed 8 h after the last dose.

RESULTS

After a single dose to patients, mean mesalazine half-life (s.d.) was 5.0 (3.6) h. At steady-state, means (s.d.) were 89.1 (78.9) ng/mL for C(min), 361.1 (240.8) ng/mL for C(max), and 7.1 (7.3) h for half-life. Mean (range) rectal mesalazine concentrations were 167 (1.4-541.6) ng/mg tissue. After a single dose in healthy volunteers, mean (s.d.) half-life was 4.0 (4.7) h. At steady-state, means (s.d.) were 22.4 (61.6) ng/mL for C(min), 359.4 (166.3) ng/mL for C(max), and 0.9 (0.5) h for half-life.

CONCLUSION

Mesalazine is released in the rectum of patients, with a bioavailability of about 40%. Tissue distribution is also appreciable. Both parameters appear higher than in healthy volunteers.

Balsalazide is superior to mesalamine in the time to improvement of signs and symptoms of acute mild-to-moderate ulcerative colitis

OBJECTIVE

Balsalazide is a novel azo-bonded 5-aminosalicylic acid treatment for mild-to-moderate ulcerative colitis. The study objective was to compare symptomatic remission rates with balsalazide and mesalamine while controlling for extent of disease and time since diagnosis in patients with active, mild-to-moderate ulcerative colitis.

METHODS

A total of 173 patients with sigmoidoscopically verified ulcerative colitis were randomized to 8 wk of double-blind treatment with balsalazide 6.75 g/day or mesalamine 2.4 g/day. Both treatments provided 2.4 g/day of oral 5-aminosalicylic acid. Patients maintained symptom diaries throughout the treatment period.

RESULTS

Overall, 46% of balsalazide- and 44% of mesalamine-treated patients achieved symptomatic remission. Higher response rates were noted in newly diagnosed patients with < or = 40 cm of disease (68% vs 61%) than in recently relapsed patients with >40 cm of disease (36% vs 25%). The median time to symptomatic remission was 12 days shorter with balsalazide (25 days) than with mesalamine (37 days). Significantly more balsalazide patients showed sigmoidoscopic (p = 0.002), stool frequency (p = 0.006), rectal bleeding (p = 0.006), and physician's global assessment score (p = 0.013) improvement by 14 days than did mesalamine patients. Similar proportions of patients reported adverse events (54% vs 64%), which were most commonly related to the gastrointestinal and central and peripheral nervous systems.

CONCLUSIONS

Balsalazide is an effective and safe treatment for mild-to-moderate ulcerative colitis. Improvement of symptoms occurs considerably earlier with balsalazide than with mesalamine.

Mesalamine induces manganese superoxide dismutase in rat intestinal epithelial cell lines and in vivo

Mesalamine (5-ASA) is effective in the treatment of inflammatory bowel diseases. However, the mechanisms of action of 5-ASA remain unclear. IEC-6 and IRD-98, nontransformed rat small intestinal epithelial cell lines, were used to examine the effect of 5-ASA on the expression of manganese superoxide dismutase (MnSOD). Rats were given 5-ASA enemas to determine the effect on colonic MnSOD expression. Treatment with 5-ASA at 0.02 or 2 mg/ml induced MnSOD mRNA levels 2.67-fold or 5.66-fold, respectively. Inhibition of 5-lipoxygenase activating protein with MK-886 or cyclooxygenase with indomethacin did not influence the level of MnSOD mRNA. Nuclear run-on experiments demonstrated an increase in de novo transcription following treatment with 5-ASA. MnSOD protein levels were induced 2-fold at 24 h and 4.23-fold at 48 h following treatment with 1 mg/ml 5-ASA. 5-ASA increased MnSOD 1.7-fold in vivo. Pretreatment with 5-ASA significantly protected IRD-98 cells from tumor necrosis factor-alpha cytotoxicity. This is the first example of transcriptional gene regulation by 5-ASA. The induction of MnSOD by 5-ASA may contribute to the therapeutic mechanism of 5-ASA.

Measurement of colonic mucosal concentrations of 5-aminosalicylic acid is useful for estimating its therapeutic efficacy in distal ulcerative colitis: comparison of orally administered mesalamine and sulfasalazine

OBJECTIVES

Oral 5-aminosalicylic acid (5-ASA) preparations have been used frequently in the treatment of ulcerative colitis. However, there have been few reports investigating the relationship between colonic mucosal concentrations of 5-ASA and its clinical efficacy when oral sulfasalazine or 5-ASA compounds were administered. The aim of this study is to compare the mucosal concentrations of 5-ASA ensured by sulfasalazine or mesalamine, and to define the clinical significance of the measurement of 5-ASA concentrations in the treatment of distal ulcerative colitis.

MATERIALS AND METHODS

Biopsies were taken from the rectum and sigmoid colon of the oral sulfasalazine group (n = 13) and the slow-release 5-ASA (mesalamine) group with (n = 5) or without (n = 11) rectal administration of 5-ASA. High-pressure liquid chromatography was used to measure the tissue concentrations of 5-ASA and its metabolites. We compared the 5-ASA concentrations of the sulfasalazine group with the mesalamine group. Furthermore, we analyzed the relationship between tissue 5-ASA concentrations and the Disease Activity Index (DAI).

RESULTS

The concentrations of 5-ASA and acetyl-5-ASA in the sulfasalazine group were higher than those in the group taking oral mesalamine alone (p < 0.01). The concentration of 5-ASA was much higher in the patients who received oral and rectal mesalamine in an enema than in the patients who had oral mesalamine alone. There was a significant inverse correlation between the DAI and concentrations of 5-ASA in the rectum (r = 0.712, p < 0.001).

CONCLUSIONS

We demonstrated that the colonic mucosal concentration of 5-ASA was significantly higher in the sulfasalazine group than in the mesalamine group. Furthermore, the concentrations of mucosal 5-ASA may be a good marker for the estimation of its efficacy in the treatment of ulcerative colitis.

Clinical pharmacology of inflammatory bowel disease therapies

Knowledge about the clinical pharmacology of medical therapy of inflammatory bowel disease has incrementally advanced. Small studies with mesalamine have suggested that intestinal mucosal concentrations of mesalamine may predict clinical response to mesalamine therapy. Increased expression of glucocorticoid receptor beta and increased expression of the multidrug resistance drug pump P-glycoprotein 170 have been proposed as markers of drug resistance to glucocorticoids. A baseline determination of thiopurine methyltransferase phenotype or genotype may predict early leukopenia in patients treated with azathioprine or 6- mercaptopurine. Serial measurement of erythrocyte 6-thioguanine nucleotides may be useful in tailoring the dose of these medications. A loading dose of intravenous azathioprine does not accelerate the time to response in patients with steroid-treated Crohn's disease; however, standard azathioprine may work more quickly than previously reported. Methotrexate, 15 to 25 mg/wk, is effective for the treatment of Crohn's disease (active or in remission), and there is no significant difference in the erythrocyte concentrations of methotrexate polyglutamate in patients with inflammatory bowel disease receiving 15 mg, compared with 25 mg, subcutaneously on a weekly basis.