Furoxan derivatives demonstrated in vivo efficacy by reducing Mycobacterium tuberculosis to undetectable levels in a mouse model of infection.

OBJECTIVES: The most recent survey conducted by the World Health Organization described Tuberculosis (TB) as one of the top 10 causes of death and the leading cause of death from a single infectious agent. The increasing number of TB-resistant cases has contributed to this scenario. In light of this, new strategies to control and treat the disease are necessary. Our research group has previously described furoxan derivatives as promising scaffolds to be explored as new antitubercular drugs. RESULTS: Two of these furoxan derivatives, (14b) and (14c), demonstrated a high selectivity against Mycobacterium tuberculosis. The compounds (14b) and (14c) were also active against a latent M. tuberculosis strain, with MIC90 values of 6.67 µM and 9.84 µM, respectively; they were also active against monoresistant strains (MIC90 values ranging from 0.61 to 20.42 µM) and clinical MDR strains (MIC90 values ranging from 3.09 to 42.95 µM). Time-kill experiments with compound (14c) showed early bactericidal effects that were superior to those of the first- and second-line anti-tuberculosis drugs currently used in therapy. The safety of compounds (14b) and (14c) was demonstrated by the Ames test because these molecules were not mutagenic under the tested conditions. Finally, we confirmed the safety, and high efficacy of compounds (14b) and (14c), which reduced M. tuberculosis to undetectable levels in a mouse aerosol model of infection. CONCLUSION: Altogether, we have identified two advanced lead compounds, (14b) and (14c), as novel promising candidates for the treatment of TB infection.

Effects of nemorosone, isolated from the plant Clusia rosea, on the cell cycle and gene expression in MCF-7 BUS breast cancer cell lines.

BACKGROUND: Breast cancer is the cause of considerable morbidity and mortality in women. While estrogen receptor antagonists have been widely used in breast cancer treatment, patients have increasingly shown resistance to these agents and the identification of novel targeted therapies is therefore required. Nemorosone is the major constituent of the floral resin from Clusia rosea and belongs to the class of polycyclic polyisoprenylated benzophenones of the acylphloroglucinol group. The cytotoxicity of nemorosone in human cancer cell lines has been reported in recent years and has been related to estrogen receptors in breast cancer cells. METHODS: Changes induced by nemorosone in the cell cycle and gene expression of the MCF-7 BUS (estrogen-dependent) breast cancer cell line were analyzed using flow cytometry and the RT(2) Profiler PCR array, respectively. RESULTS: In comparison to breast cancer cells without treatment, nemorosone induced discrete cell cycle arrest in the G1 phase and significant depletion in the G2 phase. Moreover, the compound altered the expression of 19 genes related to different pathways, especially the cell cycle, apoptosis and hormone receptors. CONCLUSION: These promising results justify further studies to clarify mechanisms of action of nemorosone, in view of evaluate the possible use of this benzophenone as adjuvant in the treatment of breast cancer.