RESUMO
The druggability of the tyrosyl-DNA phosphodiesterase 1 (Tdp1) enzyme was investigated in conjunction with topoisomerase 1 inhibition. A novel class of thiazole, aminothiazole and hydrazonothiazole usnic acid derivatives was synthesized and evaluated as Tdp1 inhibitors and their ability to sensitize tumors to topotecan, a topoisomerase inhibitor in clinical use. Of all the compounds tested, four hydrazinothiazole derivatives, 20c, 20d, 20h and 20i, inhibited the enzyme in the nanomolar range. The activity of the compounds was verified by affinity experiments as well as supported by molecular modelling. The most effective Tdp1 inhibitor, 20d, was ton-toxic and increased the effect of topotecan both in vitro and in vivo in the Lewis lung carcinoma model. Furthermore, 20d showed significant increase in the antitumor and antimetastatic effect of topotecan in mice. The results presented here justify compound 20d to be considered as a drug lead for antitumor therapy.
Assuntos
Antineoplásicos/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Diester Fosfórico Hidrolases/metabolismo , Inibidores da Topoisomerase I/farmacologia , Topotecan/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos C57BL , Modelos Moleculares , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/patologia , Teoria Quântica , Relação Estrutura-Atividade , Inibidores da Topoisomerase I/síntese química , Inibidores da Topoisomerase I/química , Topotecan/síntese química , Topotecan/químicaRESUMO
BACKGROUND: Influenza is a disease of significant morbidity and mortality, the number of anti-influenza drugs is small; many of them stimulate the appearance of resistant strains. In this work, we demonstrate activity of some usnic acid (UA) derivatives against influenza virus in vitro and in vivo. METHODS: Organic synthesis was used to prepare compounds. Antiviral activity of the compounds in vitro was evaluated by their ability to decrease the virus titer on Madin-Darby Canine Kidney cells. In vivo activity was evaluated by decrease of mortality and index of protection. RESULTS: Compounds were tested against a broad spectrum of influenza virus strains and showed activity against all used strains. One compound, [5] (valine enamine of UA), also significantly reduced lethality of infected animals and does not give rise to the appearance of resistant strains. Additional studies showed that hepatotoxicity of compound [5] is reduced comparatively to UA. CONCLUSION: Our results suggest that valine enamine of UA could be a potential candidate for the development of a new anti-influenza therapy.