Efeito de extratos da macroalga antártica Palmaria decipiens sobre a linhagem celular tumoral de câncer colorretal HCT-116 e não tumoral HaCaT

Abstract

Colorectal cancer is the third most frequent neoplasm in the world, being an important cause of mortality. Antarctica macroalgae are substances-producing organisms with potential therapeutic activities due to the environmental conditions to which they are exposed. The antitumor activity of these organisms has already been investigated, showing promising cytotoxic results against HCT-116 colorectal cancer cell lines. So far, there are no reports indicating the antitumor potential of extracts of the macroalga Palmaria decipiens against colorectal tumors. This study aimed to evaluate the effect of macroalgae extract from Antarctica Palmaria decipiens on colorectal cancer tumor cell line HCT-116 and non-tumor cell line HaCaT. The extracts were obtained by maceration, where the samples remained in contact with the solvent and the phenolic compounds present were identified by high performance liquid chromatography. The antioxidant action of the extracts was determined by the DPPH radical inhibition method. Cytotoxicity and cell viability were determined by the MTT assay, and cell morphology was assessed by Giemsa staining. Apoptosis or cell necrosis events were identified by staining with acridine orange / ethidium bromide (LA / BE) and flow cytometry. Three extracts were obtained from the macroalgae P. decipiens: MET (methanol), CLO (chloroform) and HEX (hexane). The quantification of phenolic compounds presents in the extracts identified the presence of three main compounds: gallic acid, quercetin and kaempferol. The MET extract was the one that showed significant results of cell proliferation inhibition within 72 h of treatment in the HCT-116 lineage. However, the extracts did not show dose-response action on HaCaT cells. The MET extract showed potential antioxidant activity. The 72-hour treatment with MET extract morphologically altered the colorectal cancer tumor cell line HCT-116, as well as affected cell proliferation. Exposure of HCT-116 cells to MET extract of P. decipiens for 72h indicated the presence of necrotic events, compared to fluorescence microscopy (LA / BE), flow cytometry (annexin-V / PI), ROS and MMP tests. The cell cycle assay did not show significant evidence. The results indicate that the extract of the Antarctic macroalgae P. decipiens interferes in the mechanisms of action of colorectal cancer tumor cells, acting as a potential antiproliferative and antioxidant agent. [resumo fornecido pelo autor]