Atividade antiproliferativa dos alcalóides piperidínicos (-)- cassina e (-)-espectalina sobre células de carcinoma hepatocelular humano - HepG2

Abstract

Cancer is one of the most critical problems of public health in the world and one of the main challenges for medicine in this century. The hepatocellular carcinoma is the second cause of cancer death and the fifth most incident. Unfortunately, most patients are diagnosed at advanced stage, when the treatment options are palliative. Consequently, the search for novel therapeutic options for hepatocellular carcinoma becomes imperative. In the context, the plants represent an important source for discovery of novel compounds with pharmacological potential including antineoplastic agents. Herein, we aimed to investigate in vitro antitumor potential of an alkaloid mixture derived from Senna spectabilis, (–)-cassine and (–)-spectaline. Cell viability was measured by different colorimetric methods (MTS and rezasurin assay) and trypan blue exclusion. Clonogenic formation assay were promoted in order to evaluate colony formation inspection, while cell cycle progression was determined by flow cytometry. Cytoskeleton elements and mitosis frequency were analyzed by immunofluorescence. Gene expression was determined by immunoblot (ERK1, p-ERK and p-histone H3) and qRT-PCR (Cyclin D1). Alkaloid mixture significantly reduced cell viability of cancer cells in a concentration-dependent manner. Cell proliferation reduction occurred by cell cycle arrest mainly in G1/S transition. We demonstrated that antiproliferative potential of the alkaloids is due to, at least in part, down-regulation of cyclin D1 and ERK inactivation, which is a MAPK pathway protein. Alkaloids also drastically altered F-actin and microtubules distribution pattern. (-)-cassine and (-)-spectaline alkaloids have a promise antitumor activity against hepatoma cells and may be considered for further anticancer in vivo studies