Determinação da atividade citotóxica in vitro de compostos fitoquímicos e associações em células MDBK e de melanoma (B16F10)

Abstract

Natural products are considered promising agents for cancer prevention and treatment. Melanoma is evidenced by the high malignancy and metastatic potential, being that chemotherapy is the main treatment modality, however, its promotes cytotoxicity and deleterious effects to the organism. These adversities drive research into alternative treatments for treatment of melanoma, effectively and safely. In this context, the objective of this study was to evaluate the in vitro cytotoxic activity of phenolic compounds (caffeic acid and p-coumaric acid), terpenes (eucalyptol and gamma terpinene) and flavonoid (quercetin) in murine melanoma (B16F10) and bovine kidney cells (MDBK), in addition to evaluating the associations between these and carboplatin. Phytochemicals were obtained commercially (Sigma-Aldrich ®) and were tested at concentrations of 3 to 0.02 mg.mL-1. After dilution in cell culture medium and 0.5% DMSO, the compounds and carboplatin were distributed in 96-well plates on the B16F10 and MDBK cells, which were incubated for 24 hours at 37ºC with humid atmosphere and 5% of CO2. Cell viability was assessed by MTT assay and spectrophotometer reading (540nm). All compounds showed a cytotoxic effect on melanoma cells, ranging from high to moderate cytotoxicity. Regarding cytotoxicity in MDBK, the compounds showed low to moderate levels of toxicity. The toxicity of the compounds to B16F10 cells was greater than for MDBK cells. Considering the averages of all concentrations tested, the quercetin compound showed high toxicity to B16F10 cells, and low to MDBK cells. The compounds caffeic acid, p-coumaric acid, eucalyptol and gamma terpinene showed low toxicity to MDBK and moderate toxicity to B16F10 cells. Regarding the associations between the compounds and carboplatin, the levels of toxicity varied according to the concentrations tested, and their activities were dose-dependent. Carboplatin (1 mg.mL-1) had low toxicity to melanoma cells, whereas carboplatin (1 mg.mL-1) was associated with caffeic acid, p-coumaric acid, eucalyptol, gamma terpinene and quercetin in 1 mg. mL-1, all promoted increased cellular toxicity to B16F10. Thus, it is concluded that the compounds caffeic acid, pcoumaric acid, eucalyptol, gamma terpinene and quercetin have antiproliferative activity in B16F10, and the associations of the compounds with carboplatin increased the antiproliferative activity of this chemotherapeutic in neoplastic cells. Therefore, these compounds are promising for the sequence of researches with interest in molecules with antineoplastic activity.