Efeitos citotóxicos e mecanismo de ação da eleuterina isolada de Eleutherine plicata em modelo in vitro de células c6

Abstract

Glioblastoma multiforme (GBM) is the most prevalent malignant primary tumor of the central nervous system (CNS). GBM cells are characterized by rapid proliferation and aggressive migration. There is growing demand for new therapies to treat this tumor, due to current therapeutic limitations. Quinone derivatives from plants have received increased interest as potential antiglioma drugs due to their diverse pharmacological activities such as inhibition of cell growth, inflammation, tumor invasion and promotion of tumor regression. The herb Eleutherine plicata, popularly known as Marupazinho, is widely used in popular medicine due to its pharmacological properties, containing quinone derivatives, more specifically naphthoquinones. Previous studies have demonstrated the antiglioma activity of Eleutherine plicata, which is related to three main naphthoquinone compounds – eleutherine, isoeleutherine and eleutherol – but mechanism of action remains unclear. Thus, the objective of this study was to investigate the potential cytotoxic and antiproliferative effect of eleutherin in an in vitro model of glioblastoma (C6 lineage). In vitro cytotoxicity was assessed by the MTT assay; Morphological changes were assessed by phase contrast microscopy. Apoptosis was determined by the annexin V-FITCpropidium iodide assay, and antiproliferative effects were assessed by the colony formation assay. Protein kinase B (AKT/pAKT) expression was measured by western blot, and telomerase reverse transcriptase mRNA was measured by quantitative real-time polymerase chain reaction (qRT-PCR). The results obtained indicated that eleutherin, isolated from the Hexanic fraction, had a cytotoxic effect on the C6 lineage. Structural changes were observed by image capture, with a significant reduction in colony formation, induction of apoptosis, inhibition of pAKT and reduction in telomerase expression after treatment. Thus, our study showed that the eleuterin molecule has cytotoxic activity in C6 lineage glioma.