Síntese e avaliação da atividade anti-inflamatória de novos análogos da talidomida contendo uma estrutura ftalimida aberta

Abstract

Thalidomide is a potent anti-inflammatory drug used in the treatment of various pathologies including Erythema Nodosum Leprosum (ENL), cancer, Crohn's disease and other inflammatory and vascular disorders. However, its toxic and teratogenic effects make its use limited and motivate research groups to synthesize analogues presenting similar immunomodulation efficacy, without toxic effects. Several analogs of thalidomide have been developed in the laboratory of chemistry of the UFJF. Previously, we have shown that introduction of two phthalic anhydrides into the composition significantly enhances biological activity and water solubility, without enhanced toxicity. The present work aims at the synthesis of two new analogues of thalidomide, CAT-15 and CAT-16, formed by only one open phthalic anhydride derivative, maintaining a free amino group, and the evaluation of its anti-inflammatory activity using HT- 29 and human peripheral blood mononuclear cells (PBMCs) stimulated with LPS. The cytotoxicity of the compounds was evaluated by the MTT assay, with 18 hours treatment for HT-29 cells and for 24 and 48 hours for PBMC, using increasing concentrations of thalidomide, CAT-15, CAT-16. Dexamethasone was used as a positive control. Production of TNF-α, CXCL-10, IL-6, IL-8 and IL-10 was evaluated by the ELISA method. The novel compounds were not toxic to HT-29 and PBMC cells at any of the concentrations tested, with the exception of CAT-16 at 1600μM. HT-29 cells produced large amounts of CXCL-10 in response to LPS and the results of this work show that thalidomide and the CAT-15 and CAT-16 analogs exhibit inhibitory activity on the production of this chemokine. CAT-16 compound modulated the production of CXCL-10 at lower concentrations than thalidomide in both treatment models (simultaneous and pretreatment). In contrast, CAT-15 modulation was observed only in the pre-treatment model. Regarding IL-8, thalidomide and CAT-16 inhibited their production by HT-29 cells only at the concentration of 100 μM. Unlike HT-29 cells, PBMC produced TNF-α in response to LPS, with thalidomide and CAT-16 analog being able to inhibit TNF- production at both treatment times. The CAT-15 analogue did not influence the production of TNF-α by PBMC at any of the concentrations and treatment times. This study also shows the activity of thalidomide and the analogs on IL-6 and IL-10 production by PBMC, with significant inhibition of IL-6 production by all compounds and treatment times and on IL-10 by compound CAT-15 after 48 hours of incubation. Our results suggest the applicability of the new compounds, CAT-15 and CAT-16, in the control of inflammatory responses since they inhibited the production of key molecules such as TNF-α, IL-6, IL-10, IL-8 and CXCL-10. Furthermore, these compounds have simplified structures, and low cost of production, are water soluble and have no chiral center. These results may contribute to the development of novel treatment strategies for certain inflammatory conditions.