The Essential Oil from Conyza bonariensis (L.) Cronquist (Asteraceae) Exerts an In Vitro Antimelanoma Effect by Inducing Apoptosis and Modulating the MAPKs, NF-κB, and PKB/AKT Signaling Pathways.

The characterization and cytotoxicity of the essential oil from Conyza bonariensis (L.) aerial parts (CBEO) were previously conducted. The major compound was (Z)-2-lachnophyllum ester (EZ), and CBEO exhibited significant ROS-dependent cytotoxicity in the melanoma cell line SK-MEL-28. Herein, we employed the Molegro Virtual Docker v.6.0.1 software to investigate the interactions between the EZ and Mitogen-Activated Protein Kinases (MAPKs), the Nuclear Factor kappa B (NF-κB), and the Protein Kinase B (PKB/AKT). Additionally, in vitro assays were performed in SK-MEL-28 cells to assess the effect of CBEO on the cell cycle, apoptosis, and these signaling pathways by flow cytometry and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using MAPKs inhibitors. CBEO induced a significant increase in the sub-G1 peak, as well as biochemical and morphological changes characteristic of apoptosis. The in-silico results indicated that EZ interacts with Extracellular Signal-Regulated Kinase 1 (ERK1), c-Jun N-terminal Kinase 1 (JNK1), p38α MAPK, NF-κB, and PKB/AKT. Moreover, CBEO modulated the ERK1/2, JNK, p38 MAPK, NF-κB, and PKB/AKT activities in SK-MEL-28 cells. Furthermore, CBEO's cytotoxicity against SK-MEL-28 cells was significantly altered in the presence of MAPKs inhibitors. These findings support the in vitro antimelanoma effect of CBEO through apoptosis induction, and the modulation of ERK, JNK, p38 MAPK, NF-κB, and PKB/AKT activities.

Coumarin derivative 7-isopentenyloxycoumarin induces in vivo antitumor activity by inhibit angiogenesis via CCL2 chemokine decrease.

Cancer is one of the most urgent problems in medicine. In recent years, cancer is the second leading cause of death globally. In search for more effective and less toxic treatment against cancer, natural products are used as prototypes in the synthesis of new anticancer drugs. The aim of this study was to investigate the in vivo toxicity and the mechanism of antitumor action of 7-isopentenyloxycoumarin (UMB-07), a coumarin derivative with antitumor activity. The toxicity was evaluated in vitro (hemolysis assay), and in vivo (micronucleus and acute toxicity assays). Ehrlich ascites carcinoma model was used to evaluate in vivo antitumor activity of UMB-07 (12.5, 25, or 50 mg/kg, intraperitoneally, i.p.), after 9 days of treatment, as well as toxicity. UMB-07 (2000 µg/mL) induced only 0.8% of hemolysis in peripheral blood erythrocytes of mice. On acute toxicity assay, LD50 (50% lethal dose) was estimated at around 1000 mg/kg (i.p.), and no micronucleated erythrocytes were recorded after UMB-07 (300 mg/kg, i.p.) treatment. UMB-07 (25 and 50 mg/kg) reduced tumor volume and total viable cancer cells. In the mechanism action investigation, no changes were observed on the cell cycle analysis; however, UMB-07 reduced peritumoral microvessels density and CCL2 chemokine levels. In addition, UMB-07 showed weak toxicity on biochemical, hematological, and histological parameters after 9 days of antitumor treatment. The current findings suggest that UMB-07 has low toxicity and exerts antitumor effect by inhibit angiogenesis via CCL2 chemokine decrease.

Toxicity and antitumor potential of Mesosphaerum sidifolium (Lamiaceae) oil and fenchone, its major component.

BACKGROUND: The essential oil from Mesosphaerum sidifolium (L'Hérit.) Harley & J.F.B.Pastore (syn. Hyptis umbrosa), Lamiaceae (EOM), and its major component, have been tested for toxicity and antitumor activity. METHODS: EOM was obtained from aerial parts of M. sidifolium subjected to hydro distillation, and gas chromatography-mass spectrometry was used to characterize the EOM chemical composition. The toxicity was evaluated using haemolysis assay, and acute toxicity and micronucleus tests. Ehrlich ascites carcinoma model was used to evaluate the in vivo antitumor activity and toxicity of EOM (50, 100 and 150 mg/kg), and fenchone (30 and 60 mg/kg) after 9 d of treatment. RESULTS: The EOM major components were fenchone (24.8%), cubebol (6.9%), limonene (5.4%), spathulenol (4.5%), ß-caryophyllene (4.6%) and α-cadinol (4.7%). The HC50 (concentration producing 50% haemolysis) was 494.9 µg/mL for EOM and higher than 3000 µg/mL for fenchone. The LD50 for EOM was approximately 500 mg/kg in mice. The essential oil induced increase of micronucleated erythrocytes only at 300 mg/kg, suggesting moderate genotoxicity. EOM (100 or 150 mg/kg) and fenchone (60 mg/kg) reduced all analyzed parameters (tumor volume and mass, and total viable cancer cells). Survival also increased for the treated animals with EOM and fenchone. For EOM 150 mg/kg and 5-FU treatment, most cells were arrested in the G0/G1 phase, whereas for fenchone, cells arrested in the S phase, which represents a blockage in cell cycle progression. Regarding the toxicological evaluation, EOM induced weight loss, but did not induce hematological, biochemical or histological (liver and kidneys) toxicity. Fenchone induced decrease of AST and ALT, suggesting liver damage. CONCLUSIONS: The data showed EOM caused in vivo cell growth inhibition on Ehrlich ascites carcinoma model by inducing cell cycle arrest, without major changes in the toxicity parameters evaluated. In addition, this activity was associated with the presence of fenchone, its major component.