Antitumoral activity of Amazon plant species: extracts of Apuleia leiocarpa induce apoptosis and autophagy in lung tumor cell line

Abstract

Non-small cell lung cancer (NSCLC) is one of the most common malignant tumors. Chemicals and target-directed therapy have been used to treat these tumors, but the development of resistance has hampered patient treatment. Thus, many researchers are seeking new compounds that are capable of reversing resistance. Plants from the Brazilian Amazon, such as Apuleia leiocarpa, represent an alternative source of new compounds with the potential to treat lung cancer. Increasing concentrations of A. leiocarpa extracts (25, 50 and 100 µg/ml) from stem, sapwood, root, and stem bark were tested against an NSCLC cell line (H460) for 48 h. The dichloromethane-stem (ALE3) and ethanolic-stem bark (ALE5) extracts inhibited cell viability and were further evaluated for apoptosis, loss of mitochondrial membrane potential (MMP), and expression of proteins belonging to the apoptotic and autophagic pathway. The results indicated that ALE3 and ALE5 induced dose-dependent apoptosis and loss of MMP, and while ALE3 induced the expression of apoptotic markers p53 and active caspase 3, ALE5 induced the expression of autophagy markers Beclin-1, ATG12 and LC3II. This study demonstrates for the first time that Apuleia leiocarpa possess significant antitumoral potential to fight lung cancer.