Inhibitory effect of O-propargyllawsone in A549 lung adenocarcinoma cells.

BACKGROUND: Lung cancer is the deadliest type of cancer in the world and the search for compounds that can treat this disease is highly important. Lawsone (2-hydroxy-1,4-naphtoquinone) is a naphthoquinone found in plants from the Lawsone genus that show a high cytotoxic effect in cancer cell lines and its derivatives show an even higher cytotoxic effect. METHODS: Sulforhodamine B was used to evaluate the cytotoxic activity of compounds on tumor cells. Clonogenic assay was used to analyze the reduction of colonies and wound healing assay to the migratory capacity of A549 cells. Apoptosis and necrosis were analyzed by flow cytometer and Giemsa staining. Hemolysis assay to determine toxicity in human erythrocytes. RESULTS: Lawsone derivatives were evaluated and compound 1 (O-propargyllawsone) was the one with the highest cytotoxic effect, with IC50 below 2.5 µM in A549 cells. The compound was able to reduce colony formation and inhibit cell migration. Morphological changes and cytometry analysis show that the compound induces apoptosis and necrosis in A549 cells. CONCLUSIONS: These results show that O-propargyllawsone show a cytotoxic effect and may induce apoptosis in A549 cells.

Anti-proliferative and pro-apoptotic activity of glycosidic derivatives of lawsone in melanoma cancer cell.

BACKGROUND: Melanoma is a malignant cancer that affects melanocytes and is considered the most aggressive skin-type cancer. The prevalence for melanoma cancer for the last five year is about one million cases. The impact caused of this and other types of cancer, revel the importance of research into potential active compounds. The natural products are an important source of compounds with biological activity and research with natural products may enable the discovery of compounds with potential activity in tumor cells. METHODS: The Sulforhodamine B was used to determine cell density after treatment with lawsone derivatives. Apoptosis and necrosis were analyzed by flow cytometer. Morphological changes were observed by fluorescence using the Phalloidin/FITC and DAPI stains. The clonogenic and wound healing assays were used to analyze reduction of colonies formation and migratory capacity of melanoma cells, respectability. RESULTS: In pharmacological screening, seven compounds derived from lawsone were considered to have high cytotoxic activity (GI > 75%). Three compounds were selected to assess the inhibitory concentration for 50% of cells (IC50), and the compound 9, that has IC50 5.3 µM in melanoma cells, was selected for further analyses in this cell line. The clonogenic assay showed that the compound is capable of reducing the formation of melanoma colonies at 10.6 µM concentration. The compound induced apoptotic morphological changes in melanoma cells and increased by 50% the cells dying from apoptosis. Also, this compound reduced the migratory capacity of melanoma cells. CONCLUSIONS: The results of this study showed that the evaluated lawsone derivatives have potential activity on tumor cells. The compound 9 is capable of inducing cell death by apoptosis in melanoma cells (B16F10).