Anti-inflammatory activity of a pteridine derivative (4AZA2096) alleviates TNBS-induced colitis in mice

Diet supporting therapy for inflammatory bowel diseases

PURPOSE

Non-specific inflammatory bowel diseases (IBD) include Crohn's disease and ulcerative colitis. More and more often attention is paid to the possibility of dietary support for inflammatory bowel diseases.

METHODS

The following review article considers the role of dietary components in the treatment of IBD as: pteridines, probiotics, bovine immunoglobulin, vitamin D, omega-3, flavonoids, polyphenols, curcumin and phosphatidylcholine. The article also discusses plant raw materials of arjuna, soy protein and nettles, trying to summarize their effect on quenching the inflammatory process within the intestines. This review focuses on the possibilities of dietary components and supplementation use to improve the pharmacotherapy response as well as the general clinical patients' condition.

RESULTS

The mechanism of action of supportive therapy is based on reduction in oxidative stress, maintaining the adequate balance between Th1 and Th2 lymphocytes by affecting cytokines, increasing riboflavin supply for macrophages, increasing expression of vitamin D receptor, regulation by decreasing the expression of NF-κB in liver cells and ability to inhibit the COX2 entrance and inactivate prostaglandins that are involved in the inflammatory process and 12-lipoxygenase pathway inhibition.

CONCLUSION

Considering clinical researches, it seems that the use of the above-mentioned ingredients in the diet of patients suffering IBD may positively influence the treatment process and maintenance of remission.

Pteridine derivatives: novel low-molecular-weight organogelators and their piezofluorochromism

Here, π-conjugated compounds based on pteridine derivatives were synthesized and their self-assembling behaviors in a variety of organic solvents and piezofluorochromism were studied.

Therapeutic potential of pteridine derivatives: A comprehensive review

Pteridines are aromatic compounds formed by fused pyrazine and pyrimidine rings. Many living organisms synthesize pteridines, where they act as pigments, enzymatic cofactors, or immune system activation molecules. This variety of biological functions has motivated the synthesis of a huge number of pteridine derivatives with the aim of studying their therapeutic potential. This review gathers the state-of-the-art of pteridine derivatives, describing their biological activities and molecular targets. The antitumor activity of pteridine-based compounds is one of the most studied and advanced therapeutic potentials, for which several molecular targets have been identified. Nevertheless, pteridines are also considered as very promising therapeutics for the treatment of chronic inflammation-related diseases. On the other hand, many pteridine derivatives have been tested for antimicrobial activities but, although some of them resulted to be active in preliminary assays, a deeper research is needed in this area. Moreover, pteridines may be of use in the treatment of many other diseases, such as diabetes, osteoporosis, ischemia, or neurodegeneration, among others. Thus, the diversity of the biological activities shown by these compounds highlights the promising therapeutic use of pteridine derivatives. Indeed, methotrexate, pralatrexate, and triamterene are Food and Drug Administration approved pteridines, while many others are currently under study in clinical trials.

DNFB-DNS hapten-induced colitis in mice should not be considered a model of inflammatory bowel disease

BACKGROUND

The dinitrofluorobenzene/dinitrosulfonic acid (DNFB/DNS) model was originally described as an experimental model of intestinal inflammation resembling human ulcerative colitis (UC). Due to the absence of acceptable UC experimental models for pharmacological preclinical assays, here we examine the immune response induced in this model.

METHODS

Balb/c mice were sensitized by skin application of DNFB on day 1, followed by an intrarectal challenge with DNS on day 5. We further expanded this model by administering a second DNS challenge on day 15. The features of colonic inflammation and immune response were evaluated.

RESULTS

The changes observed in colonic tissue corresponded, in comparison to the trinitrobenzene sulfonic acid (TNBS) colitis model, to a mild mucosal effect in the colon, which spontaneously resolved in less than 5 days. Furthermore, the second hapten challenge did not exacerbate the inflammatory response. In contrast to other studies, we did not observe any clear involvement of tumor necrosis factor alpha (TNF-α) or other Th1 cytokines during the initial inflammatory response; however, we found that a more Th2-humoral response appeared to mediate the first contact with the hapten. An increased humoral response was detected during the second challenge, although an increased Th1/Th17-cytokine expression profile was also simultaneously observed.

CONCLUSIONS

On the basis of these results, although the DNFB/DNS model can display some features found in human UC, it should be considered as a model for the study of the intestinal hypersensitivity seen, for example, during food allergy or irritable bowel syndrome but not intestinal inflammation per se.

Immunosuppressive activity of a new pteridine derivative (4AZA1378) alleviates severity of TNBS-induced colitis in mice

Besides TNF, activated T cells play a central role in the pathogenesis of inflammatory bowel diseases such as Crohn's disease. New therapies are still awaited to cure these often debilitating diseases. Natural occurring pteridines such as tetrahydrobiopterin (BH4) and neopterin have been reported to have immune modulating activities. Starting from a pteridine scaffold library, we intended to select compounds with potent in vitro inhibitory effects on T cells and to evaluate in vivo efficacy of selected compounds on trinitrobenzenesulphonate (TNBS) colitis in mice. Compound 4AZA1378 was selected because it potently inhibits human T cell proliferation at low nM concentrations (IC50 4 nM) while an almost 50-fold higher concentration was needed to inhibit LPS-induced TNF production. Mice treated with 4AZA1378 had less severe signs of colitis after TNBS rectal administration, with a more rapid weight recovery. Myeloperoxidase (MPO) activity and intralesional cytokine production were lower in mice of the treated groups. Furthermore anti-TNBS antibody responses were completely inhibited by treatment with 4AZA1378. In conclusion, we identified a pteridine analogue 4AZA1378 with immunosuppressive activity and a strong remission-inducing effect in TNBS colitis, supporting further pre-clinical and clinical development of this novel molecule for treatment of inflammatory diseases.