Cytotoxic effects of natural and semisynthetic cucurbitacins on lung cancer cell line A549.

Cucurbitacins and their derivatives are triterpenoids that are found in various plant families, and are known for their pharmacological and biological activities, including anti-cancer effects. Lung cancer represents a major public health problem, with non-small-cell lung cancer (NSCLC) being the most frequent and aggressive type of lung cancer. The objective of this work was to evaluate four cucurbitacins (CUCs) for their cytotoxic activity, effects on apoptosis induction, cell cycle progression, anti-migratory, and anti-invasive effects on the human NSCLC cell line (A549 cells). Our findings showed that these CUCs could suppress human NSCLC cell growth in vitro through their effects on the PI3Kinase and MAPK pathways, which lead to programmed cell death induction, as well as inhibition of cell migration and cell invasion. Additionally, these effects culminate in apoptosis induction and G2/M cell cycle arrest by modulating cyclin B1 expression, and in the mitigation of strategic steps of lung cancer metastasis, including migration and invasion of A549 cells. These results suggest that two natural (DDCB and CB) and two novel semisynthetic derivatives of cucurbitacin B (ACB and DBCB) could be considered as promising compounds with antitumor potential.

Synergistic Antiproliferative Effects of a New Cucurbitacin B Derivative and Chemotherapy Drugs on Lung Cancer Cell Line A549.

Nonsmall cell lung cancer (NSCLC) represents an important cause of mortality worldwide due to its aggressiveness and growing resistance to currently available therapy. Cucurbitacins have emerged as novel potential anticancer agents showing strong antiproliferative effects and can be promising candidates for combined treatments with clinically used anticancer agents. This study investigates the synergistic antiproliferative effects of a new semisynthetic derivative of cucurbitacin B (DACE) with three chemotherapy drugs: cisplatin (CIS), irinotecan (IRI), and paclitaxel (PAC) on A549 cells. The most effective combinations were selected for studies of the mechanism of action. Using an in silico tool, DACE seems to act by a different mechanism of action when compared with that of different classes of drugs already used in clinical settings. DACE also showed potent synergic effects with drugs, and the most potent combinations induced G2/M cell cycle arrest by modulating survivin and p53 expression, disruption of F-actin cytoskeleton, and cell death by apoptosis. These treatments completely inhibited the clonogenic potential and did not reduce the proliferation of nontumoral lung cells (MRC-5). DACE also showed relevant antimigratory and anti-invasive effects, and combined treatments modulated cell migration signaling pathways evolved with metastasis progression. The effects of DACE associated with drugs was potentiated by the oxidant agent l-buthionine-sulfoximine (BSO), and attenuated by N-acetilcysteine (NAC), an antioxidant agent. The antiproliferative effects induced by combined treatments were attenuated by a pan-caspase inhibitor, indicating that the effects of these treatments are dependent on caspase activity. Our data highlight the therapeutic potential of DACE used in combination with known chemotherapy drugs and offer important insights for the development of more effective and selective therapies against lung cancer.

Evaluation of the Wound Healing Properties of Hancornia speciosa Leaves.

The leaves of Hancornia speciosa Gomes (Apocynaceae), a medicinal species found in the Brazilian cerrado biome, are traditionally used to treat wounds and inflammatory disorders. The goal of the present study was to investigate the in vitro wound healing properties of ethanolic extract of H. speciosa leaves and its isolated compounds, using the scratch assay, and to evaluate their effects on the release of the pro-inflammatory cytokine tumor necrosis factor (TNF-α) by lipopolysaccharide (LPS)-stimulated human acute monocytic (THP-1) cells. H. speciosa ethanolic extract significantly increased (42.8% ± 5.4 at 25 µg/mL) cell migration and proliferation of fibroblasts compared with control cells, as well as the isolated compounds bornesitol (80.8% ± 5.1) and quinic acid (69.1% ± 6.2), both assayed at 50 µM. TNF-α release by LPS-stimulated THP-1 cells was significantly reduced by the ethanolic extract (62.9% ± 8.2, i.e. 1791.1 ± 394.7 pg/mL) at 10 µg/mL, bornesitol (48.9% ± 0.9, i.e. 2461.6 ± 43.1 pg/mL) at 50 µM, and quinic acid (90.2% ± 3.4, i.e. 473.5 ± 164.4 pg/mL) and rutin (82.4% ± 5.6, i.e. 847.0 ± 271.8 pg/mL) at 10 µM. These results provided evidences to support the traditional use of H. speciosa leaves to treat wounds and inflammatory disorders.