Prodigiosinas isoladas de microrganismos associados a Zoanthus sociatus do arquipélago Fernando de Noronha com potencial anticâncer

Abstract

Cancer is one of the biggest causes of death in the world, it is fundamentally a genetic disease, which appears as a consequence of pathological changes in the information contained in the DNA. In an attempt to increase the arsenal of molecules with potential therapeutic activity and to incorporate the sustainable use of biodiversity to the process of research and development of drugs of marine origin, microorganisms associated with marine animals have been widely studied. The latter are excellent producers of compounds with diverse biological activities. The present work aimed to prospect substances with antitumor potential obtained from microorganisms associated to Zoanthus sociatus collected in the Brazilian oceanic islands. In this work, the pharmacological potential of the microorganism recovered from Zoanthus sociatus collected in the Brazilian oceanic islands was investigated in tumor cells in culture. Nineteen strains were isolated, 15 of which yielded crude extracts (EB) with antiproliferative effect (inhibition of growth> 75%) in HCT 116 human colorectal cancer cells at a concentration of 50 μg / mL after 72h of incubation. The EB of the BRA-535 line presented IC50 = 4.8 μg / mL and was selected to proceed with the purification of the active principles and characterization of the biological effects in tumor cells. Through chemical fractionation, streptorubin B and undecylprodigiosin, the two belonging to the prodigiosin class, family of molecules known for their anticancer, antimalarial, antimicrobial and immunosuppressive properties were isolated. The cytotoxicity of the two was then investigated by the SRB assay, were tested in 3 tumor lines (HCT 116, B16-F10 and PC-3M) and in 2 non-tumoral lines (L929 and HEK293A). The two substances isolated after 24, 48 and 72 hours were very potent in the HCT 116 strain. Strepubutin B at concentrations of 5, 50 and 500 nM were tested in the clonogenic assay and significantly reduced the number of colonies (p < 0.05) at the concentration of 50 and 500 nM and doxurubicin. We observed that streptorubin B treated HCT 116 cells are excited by blue (488nm) and red (633nm) lasers causing detectable fluorescence emission in both red laser channels and blue laser detectors. The violet laser (405nm) did not cause excitation of the cells treated with streptorubin B at the concentrations and detectors used. The mechanism of action assays continued with streptorubin B. Concerning morphology, an increase of picnosis was observed in a 24h incubation at 500 and 1000 nM and 48h concentrations at concentrations of 50 and 500 nM. There was an increase in the number of dead cells observed by the membrane integrity assay using DAPI as well as the decrease in cell proliferation by the cell count assay. No cell cycle arrest was observed at any stage. Increased DNA fragmentation of the HCT 116 cells treated with streptorubin B in 48h incubation. Using confocal microscopy, we observed that streptorubin B accumulates in organelles near the nucleus in HCT 116 cells, possibly in lysosomes or endoplasmic reticulum. Streptorubin B and undecylprodigiosine despite its occurrence already described, no work with streptorubin B has been performed to evaluate its cytotoxic activity in tumor lines, this being the first report on its properties inducing morphological alterations and induction of DNA fragmentation in cells tumor, thus opening up the perspective of its use, aiding in the studies related to the cancer.