Avaliação da atividade citotóxica, antitumoral, mutagênica, recombinogênica e genotóxica do [Cu(Dox)(Phen)]2+

Abstract

The ternary complex of Copper(II), 1,10-phenanthroline and doxycycline [Cu(dox)(phen)]2+, developed as a candidate for the antitumoral drug, showed high cytotoxicity and DNA cleavage activity by oxidative mechanism and interleaving to the molecule, suggesting studies that help to better understand its mechanism of action. In this context, the aim of the present study was to investigate its cytotoxic activity and genotoxic potential in tumor and non-tumor cells cultured in vitro and its antitumoral activity in vivo using BALB/C mice inoculated with the cell lines of sarcoma 180 and Ehrlich's tumour, as well as evaluating the mutagenic and recombinogenic effects of [Cu(dox)(phen)]2+ using the somatic mutation and recombination test (SMART) on Drosophila melanogaster. The partition coefficient of [Cu(dox)(phen)]2+ was determined in octanol water at pH 7.4. Cytotoxicity was assessed using the resazurin test on three lines of tumorigenic cells (sarcoma TG180, sarcoma S180 and melanoma B16F10) and a non-tumogenic lineage (macrophages RAW 264.7) in different concentrations. Genotoxic activity was evaluated by in vitro Micronucleus Test at concentrations of 1; 0.25; 0.1; and 0.05μM. The in vivo antitumoral activity test was performed using sarcoma S180 at concentrations of 5, 10 and 15 mg/Kg of animal and the survival time and changes in weight of mice were determined using an Ehrlich ascitic tumor model at concentrations of 1 and 8 mg/Kg of animal. The SMART test was performed with 72h larvae at standard and high bioactivation crossings at three concentrations of [Cu(dox)(phen)]2+ (6.92; 13.84 or 27.6mM). Marked trans-heterozygous and balanced heterozygous individuals were analyzed to determine the mutational and recombinogenic events that occurred in the cells. The results obtained from cell lines maintained in vitro indicated that the compound presents moderate cytotoxic potential, with selective cell growth inhibition for tumor cells, especially B16F10. Its main mechanism of action seems to be through the generation of EROs. [Cu(dox)(phen)]2+ significantly reduced the size of the tumor implanted in the animal model, suggesting great antitumor potential. [Cu(dox)(phen)]2+ is selectively cytotoxic to B16F10 and showed high in vivo chemotherapy potential against S180 sarcoma and Ehrlich's ascitic tumor. Regarding the mutagenic and recombinogenic effects it was verified that [Cu(dox)(phen)]2+ significantly increased the frequencies of mutant cells in both crossings of D. melanogaster, mainly by recombination. These data show that [Cu(dox)(phen)]2+ is a direct recombinogenic agent, independent of bioactivation. The results obtained indicate that [Cu(dox)(phen)]2+ is a promising candidate for the development of new chemotherapeutic drugs, once it has shown selective behavior for tumor cells and has satisfactory selectivity to cross the membrane and reach the DNA, its main target of action.