Infliximab and ulcerative colitis

Ethanol extract of Piper wallichii ameliorates DSS-induced ulcerative colitis in mice: Involvement of TLR4/NF-κB/COX-2 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Piper wallichii (family: Piperaceae), a folk herbal medicine with anti-inflammatory and anti-thrombotic properties, has been traditionally used to treat rheumatic arthralgia, lumbocrural pain, gastrointestinal flatulence, and other intestinal diseases in China, Thailand, and India. However, there is no scientific report on the efficacy and potential mechanisms of Piper wallichii for ulcerative colitis (UC).

AIM OF THE STUDY

The study aims to investigate the therapeutic effect and possible molecular mechanisms of the ethanol extract of Piper wallichii (EEPW) on DSS-induced UC in BALB/c mice.

MATERIALS AND METHODS

The main components in EEPW were characterized by UPLC-QE-Orbitrap-MS. Subsequently, the anti-inflammatory effect of EEPW in vitro was preliminarily evaluated in RAW264.7 cells stimulated with LPS. UC model mice were triggered by free access to 4% DSS aqueous solution for 12 consecutive days, and simultaneously, EEPW (25, 50, and 100 mg/kg) and tofacitinib (positive control, 30 mg/kg) were orally administrated, respectively. The therapeutic efficacy of EEPW on UC was assessed by body weight, DAI, colon length, and pathological morphology. Besides, we investigated the effects of EEPW on intestinal barrier function, inflammatory factors, and immune systems of UC mice through immunohistochemistry (IHC), flow cytometry, and other techniques. Moreover, the expression of related proteins in the TLR4/NF-κB/COX-2 pathway was analyzed by Western blot.

RESULTS

A total of 14 components were identified in the positive and negative modes, including isofutoquinol A (11), hancinone C (12), and futoquinol (14) which characterized by references. In the RAW264.7 cells experiments, the extract significantly suppressed the levels of TNF-α and IL-6. More importantly, EEPW distinctly improved the symptoms of DSS-induced UC mice as reflected by a significant recovery from body weight, colon length, pathological injuries of the colon, and so on. Further research found that EEPW remarkably restored the levels of occludin, promoted proliferation, and inhibited apoptosis in colon to maintain the integrity of intestinal barrier. In addition, the down-regulation of TNF-α and IL-1β in colon, Th1 and Th17 cells in spleen, as well as the up-regulation of IL-10 in colon and Th2 cells in spleen were distinctly observed in EEPW-treated groups. Furthermore, the protein expression of TLR4, p-IκB-α, p-p65, and COX-2 were significantly inhibited by EEPW.

CONCLUSIONS

This study confirmed for the first time that EEPW effectively ameliorated DSS-induced UC in mice, which might be related to improving intestinal barrier function, maintaining the levels of inflammatory factors, and regulating the immune system. In addition, we found that the anti-inflammatory effect of EEPW on UC mice was involved in the TLR4/NF-κB/COX-2 signaling pathway. In conclusion, Piper wallichii can be used as a candidate for the treatment of UC.

Identification, synthesis, and biological evaluation of 6-[(6R)-2-(4-fluorophenyl)-6-(hydroxymethyl)-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrimidin-3-yl]-2-(2-methylphenyl)pyridazin-3(2H)-one (AS1940477), a potent p38 MAP kinase inhibitor

Several p38 MAPK inhibitors have been shown to effectively block the production of cytokines such as IL-1β, TNFα, and IL-6. Inhibitors of p38 MAP kinase therefore have significant therapeutic potential for the treatment of autoimmune disease. Compound 2a was identified as a potent TNFα production inhibitor in vitro but suffered from poor oral bioavailability. Structural modification of 2a led to the discovery of tetrahydropyrazolopyrimidine derivatives, exemplified by compound 3, with an improved pharmacokinetic profile. We found that blocking metabolism at the methyl group of the amine and constructing the tetrahydropyrimidine core were important to obtaining compounds with good biological profiles and oral bioavailability. Pursuing the structure-activity relationships of this series led to the discovery of AS1940477 (3f), with excellent cellular activity and a favorable pharmacokinetic profile. This compound represents a highly potent inhibitor of p38 MAP kinase with regard to in vivo activity in an adjuvant-induced arthritis model.

The Discovery of VX-745: A Novel and Selective p38α Kinase Inhibitor

The synthesis of novel, selective, orally active 2,5-disubstituted 6H-pyrimido[1,6-b]pyridazin-6-one p38α inhibitors is described. Application of structural information from enzyme-ligand complexes guided the selection of screening compounds, leading to the identification of a novel class of p38α inhibitors containing a previously unreported bicyclic heterocycle core. Advancing the SAR of this series led to the eventual discovery of 5-(2,6-dichlorophenyl)-2-(2,4-difluorophenylthio)-6H-pyrimido[1,6-b]pyridazin-6-one (VX-745). VX-745 displays excellent enzyme activity and selectivity, has a favorable pharmacokinetic profile, and demonstrates good in vivo activity in models of inflammation.

Release and activity of anti-TNFalpha therapeutics from injectable chitosan preparations for local drug delivery

BACKGROUND

Tumor necrosis factor alpha (TNFalpha) is a cytokine that regulates immune and inflammatory overactivation in various pathological states. Protein therapeutics may antagonize this cytokine, but may also have systemic toxicities. Small molecule natural products are also efficacious, but can suffer from poor oral bioavailability. A drug delivery vehicle is needed to sustain release of active therapeutics and address localized inflammation.

MATERIALS

Chitosan is a biocompatible aminopolysaccharide that undergoes thermally-initiated gelation in cosolutions with glycerophosphate (GP), and may entrap and sustain release of additive therapeutics. Gelation time and temperature of chitosan/GP were evaluated by turbidity (OD(350)), as was the kinetic effect of bovine serum albumin (BSA) entrapment. We investigated in vitro release of BSA and various anti-TNF agents (curcumin, sTNFRII, anti-TNF antibody) and confirmed in vitro activity of the released drugs using an established bioassay.

RESULTS

Turbidity results show that chitosan/GP thermogel achieves gelation at 37 degrees C within 10 min, even with significant protein loading. Sustained BSA release occurred with 50% retained at 7 days. All anti-TNF therapeutics exhibited sustained release, with 10% of sTNFRII and anti-TNF antibody remaining after 7 days and 10% of curcumin remaining after 20 days. After release, each compound antagonized TNFalpha-cytotoxicity in murine fibrosarcoma cells.

CONCLUSIONS

This study demonstrates that thermogelling chitosan/GP entraps and sustains release of a broad range of anti-TNF agents. Such delivery of disease-modifying therapy could establish a drug depot to treat local inflammation. The breadth of molecular sizes demonstrates significant versatility, and slow release could protect against toxicities of systemic delivery.

Infliximab in ulcerative colitis is associated with an increased risk of postoperative complications after restorative proctocolectomy

PURPOSE

Little data exist regarding infliximab use in surgical decision making and postoperative complications in ulcerative colitis. Our goals were to determine the rate of postoperative complications in infliximab-treated ulcerative colitis patients undergoing restorative proctocolectomy and to determine whether three-stage procedures are more often necessary.

METHODS

We studied a group of infliximab-treated patients and matched control subjects who underwent two-stage restorative proctocolectomy between 2000 and 2006. Postoperative complications were compared. In addition, the rate of three-stage procedures was compared between all infliximab- and noninfliximab-treated patients.

RESULTS

A total of 523 restorative proctocolectomies were performed. In the infliximab group, there were 46 two-stage and 39 three-stage procedures. Covariate-adjusted odds of early complication for the infliximab group was 3.54 times that of controls (P = 0.004; 95 percent confidence interval (CI), 1.51-8.31). The odds of sepsis were 13.8 times greater (P = 0.011; 95 percent CI, 1.82-105) and the odds of late complication were 2.19 times greater (P = 0.08; 95 percent CI, 0.91-5.28) for infliximab. The odds of requirement for three-stage procedures was 2.07 times greater in the infliximab group (P = 0.011; 95 percent CI, 1.18-3.63).

CONCLUSIONS

Infliximab increases the risk of postoperative complications after restorative proctocolectomy and has altered the surgical approach to ulcerative colitis. Potential benefits of infliximab should be balanced against these risks.

Synthesis and SAR of new pyrrolo[2,1-f][1,2,4]triazines as potent p38 alpha MAP kinase inhibitors

A novel series of compounds based on the pyrrolo[2,1-f][1,2,4]triazine ring system have been identified as potent p38 alpha MAP kinase inhibitors. The synthesis, structure-activity relationships (SAR), and in vivo activity of selected analogs from this class of inhibitors are reported. Additional studies based on X-ray co-crystallography have revealed that one of the potent inhibitors from this series binds to the DFG-out conformation of the p38 alpha enzyme.

Synthesis and SAR of p38α MAP kinase inhibitors based on heterobicyclic scaffolds

The synthesis and structure-activity relationships (SAR) of p38alpha MAP kinase inhibitors based on heterobicyclic scaffolds are described. This effort led to the identification of compound (21) as a potent inhibitor of p38alpha MAP kinase with good cellular potency toward the inhibition of TNF-alpha production. X-ray co-crystallography of an oxalamide analog (24) bound to unphosphorylated p38alpha is also disclosed.

Serum soluble TNF receptor I and II levels correlate with disease activity in IBD patients

BACKGROUND

Tumor necrosis factor alpha (TNFalpha) is a proinflammatory cytokine and an important mediator in the pathophysiology of inflammatory bowel disease (IBD). The effects of TNFalpha are mediated by 2 specific receptors, a 55-kDa protein (TNF-RI) and a 75-kDa receptor (TNF-RII), which are usually bound to the cell surface. Soluble TNF receptors I and II (sTNF-RI + II) are released by proteolytic cleavage of the extracellular domains of these receptors. Soluble TNF-Rs act as TNF antagonists and can inhibit TNFalpha-mediated proinflammatory effects.

METHODS

Levels of sTNF-RI + II were measured using commercially available enzyme-linked immunosorbent assays (ELISAs). Serum levels of sTNF-RI + II of 76 healthy volunteers were compared to serum levels of 373 clinically well-characterized patients with Crohn's disease (CD) and 118 patients with ulcerative colitis (UC) with different disease activity from the German IBD competence network serum bank. CD patient subgroups were defined according to the Vienna Classification.

RESULTS

The serum levels of sTNF-RI were significantly increased in all groups (active, chronic active, and remission) of CD and UC patients compared to healthy controls. sTNF-RII levels were significantly higher in active CD patients compared to UC patients with no overlap of the 95% confidence interval. Significantly higher values of sTNF-RII compared to controls were also observed in CD patients and UC patients in remission. There was no statistically significant difference in sTNF-RI or sTNF-RII levels when patient subgroups were analyzed according to disease behavior or disease localization.

CONCLUSION

sTNF-RI is upregulated in the serum of IBD patients compared to healthy controls and could be used as a marker for disease activity. sTNF-RII levels are significantly more elevated in serum of active CD patients as compared to UC and could be used as an additional parameter to discriminate both diseases.

The histamine H4 receptor: A novel modulator of inflammatory and immune disorders

All 4 known histamine receptors (H(1)R, H(2)R, H(3)R and H(4)R) have been used or proposed as therapeutic targets for varied diseases. This article reviews the recent progress in understanding the function of the recently described histamine receptor H(4)R in a variety of immune responses and the potential therapeutic value of H(4)R antagonists. The H(4)R is expressed primarily on cells involved in inflammation and immune response. It has effects on chemotaxis, as well as cytokine and chemokine production of mast cells, eosinophils, dendritic cells, and T cells. H(4)R antagonists, JNJ 7777120 and JNJ 10191584 (also known as VUF 6002) have been developed with excellent affinity and selectivity towards human and rodent H(4)R. These antagonists also demonstrate efficacy as anti-inflammatory agents in vivo. H(4)R antagonists have shown promising activity in down-regulating immune responses in a range of animal disease models including acute inflammation, hapten-mediated colitis, and allergic airway inflammation. Due to its distribution on immune cells and its proven role in inflammatory functions, the H(4)R appears to be a therapeutic target for the treatment of a variety of immune disorders.

Rosiglitazone, a PPARgamma ligand, modulates signal transduction pathways during the development of acute TNBS-induced colitis in rats

Recent studies have shown that peroxisome proliferator-activated receptor gamma (PPARgamma), a highly nuclear receptor expressed in the colon, may participate in the control of inflammation, especially in regulating the production of immunomodulatory and inflammatory mediators, cellular proliferation and apoptosis. In order to delve into the anti-inflammatory mechanisms and signalling pathways of PPARgamma agonists, we have studied the effects of rosiglitazone, a PPARgamma agonist on the extent and severity of acute ulcerative colitis caused by intracolonic administration of 2,4,6-trinitribenzene sulfonic acid (TNBS) in rats. The inflammatory response was assessed by gross appearance, myeloperoxidase (MPO) activity, tumour necrosis factor alpha (TNF-alpha) levels and a histological study of the lesions. We determined prostaglandin E2 production as well as the cyclooxygenases (COX)-1 and -2 expressions by immunohistochemistry and Western blotting. The nuclear factor kappa (NF-kappaB) p65 and p38 mitogen-activated protein kinase (MAPK) expression levels were also measured by Western blotting. Finally, since PPARgamma agonists modulate apoptosis, we tried to clarify its effects under early acute inflammatory conditions. Inflammation following TNBS induction was characterized by increased colonic wall thickness, edema, diffuse inflammatory cells infiltration, necrosis reaching an ulcer index (UI) of 9.66+/-0.66 cm(2) and increased MPO activity and TNF-alpha colonic levels. Rosiglitazone treatment significantly reduced the morphological alteration associated with TNBS administration and the UI with the highest dose. In addition, the degree of neutrophil infiltration and the cytokine levels were significantly ameliorated. Rosiglitazone significantly reduced the rise in the prostaglandin (PG) E(2) generation compared with TNBS group. The COX-1 levels remained stable throughout the treatment in all groups. The COX-2 expression was elevated in TNBS group; however rosiglitazone administration reduced the COX-2 overexpression. A high expression of NF-kappaB p65 and p38 MAPK proteins appeared in colon mucosa from control TNBS-treated rats; nevertheless, PPARgamma agonist treatment drastically decreased them. There were no significant changes in apoptosis after rosiglitazone treatment when compared to TNBS group. In conclusion, rosiglitazone seems to modulate the acute colitis through NF-kappaB p65 and p38 MAPK signalling pathways.