RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Cancer is an inflammatory disease because carcinogenesis and tumor progression depend on intrinsic and extrinsic inflammatory pathways. Although species of the genus Aspidosperma are widely used to treat tumors, and there is ethnopharmacological evidence for traditional use of the species A. subincanum as an anti-inflammatory agent, its antineoplastic potential is unknown. AIM OF THE STUDY: To evaluate toxic effects of the indole alkaloid-rich fraction (IAF) of A. subincanum on the MCF7 cell line and identify some of the anti-inflammatory mechanisms involved. MATERIALS AND METHODS: Chromatographic analyses were performed by ultra-high-performance liquid chromatography with electrospray ionization mass spectrometry, and cytotoxic and antiproliferative effects of IAF were verified by MTT and clonogenic assays. Cell cycle alterations were analyzed by measuring DNA content, while propidium iodide and acridine orange staining was performed to determine the type of induced cell death. The expression of apoptosis markers and proteins involved in cell proliferation and survival pathways was analyzed by immunoblotting, RT-qPCR, and ELISAs. Interference with redox status was investigated using a DCFH-DA probe and by measuring catalase activity. RESULTS: Chromatographic analyses showed that IAF is a complex mixture containing indole alkaloids. IAF selectively exerted toxic and antiproliferative effects, elevating the Bax/Bcl-xL ratio and inducing apoptosis in MCF7 cells. IAF decreased intracellular reactive oxygen species levels and increased catalase activity, while reducing the IL-8 level and suppressing COX-2 expression. CONCLUSIONS: IAF induces apoptosis in MCF7 cells by suppressing COX-2 expression while reducing IL-8 levels and intracellular content of reactive oxygen species.
