Edible Tuber Amorphophallus paeoniifolius (Dennst.) Extract Induces Apoptosis and Suppresses Migration of Breast Cancer Cells.

Medicinal plants offer enormous possibilities in the quest of novel bioactive formulation for cancer therapy. Here, we studied the anticancer efficacy of the extract of edible tuber Amorphophallus paeoniifolius (Dennst.) (APTE) against estrogen positive MCF-7 and triple negative MDA-MB-231 breast cancer cell lines. APTE showed significant cytotoxic activity in both MCF-7 and MDA-MB-231 cells in a dose and time-dependent manner. The effect of APTE on metastatic parameters e.g., migration, adhesion, and invasion in MCF-7 and MDA-MB-231 cells were studied using wound healing, collagen adhesion, and transwell matrigel invasion assays, respectively. APTE significantly reduced migration in both the cell lines, however, its effect on the inhibition of adhesion and invasion was higher in MDA-MB-231 cells. Annexin V-Cy3 staining suggested that APTE induced apoptosis in these cells which was further validated by attenuation of antiapoptotic Bcl-2 and induction of pro-apoptotic Bax, Caspase-7 expression and cleavage of PARP. High resolution-liquid chromatography mass spectroscopy analysis with bioactive ethyl acetate and butanol fractions of APTE detected several compounds with anticancer activities. Overall, the study described the mechanism of anticancer activity of a common edible tuber A. paeoniifolius and contributes to growing list of naturally occurring chemo-preventive strategies.

Octahedral copper(ii)-diimine complexes of triethylenetetramine: effect of stereochemical fluxionality and ligand hydrophobicity on CuII/CuI redox, DNA binding and cleavage, cytotoxicity and apoptosis-inducing ability.

Octahedral copper(ii) complexes of the type [Cu(trien)(diimine)](ClO4)2 (1-4), where trien is triethylenetetramine and diimine is 2,2'-bipyridine (1), 1,10-phenanthroline (2), 5,6-dimethyl-1,10-phenanthroline (3), and 3,4,7,8-tetramethyl-1,10-phenanthroline (4), have been isolated. Single crystal X-ray structures of 1 and 2 reveal that the coordination geometry around Cu(ii) is tetragonally distorted octahedral. The stereochemical fluxionality of the complexes illustrates the observed trend in CuII/CuI redox potentials and DNA binding affinity (Kb: 1, 0.030 ± 0.002 < 2, 0.66 ± 0.01 < 3, 1.63 ± 0.10 < 4, 2.27± 0.20 × 105 M-1), determined using absorption spectral titration. All complexes effect oxidative DNA cleavage more efficiently than hydrolytic DNA cleavage. The bpy complex 1 with stereochemical fluxionality lower than its phen analogue 2 shows a higher cytotoxicity against both A549 lung (IC50, 3.3 µM) and MCF-7 human breast (IC50, 3.9 µM) cancer cells, and induces the generation of the highest amount of ROS in A549 cells. Complex 3 with a higher stereochemical fluxionality and higher ligand hydrophobicity exhibits a higher DNA binding and cleavage ability and higher cytotoxicity (IC50, 2.1 µM) towards MCF-7 cells. Complex 4 with a still higher stereochemical fluxionality displays the highest DNA binding and cleavage ability but a lower cytotoxicity towards both A549 and MCF-7 cell lines due to its tendency to form a five-coordinated complex with the uncoordinated amine group. Annexin V.Cy3 staining and immunoblot analysis demonstrate the mechanism of cell death caused by 1 and 2. The finding of the up-regulation of the pro-apoptotic Bax protein and down-regulation of PARP protein in western blot analysis confirms the induction of apoptosis by these complexes.

Nerve growth factor from Indian Russell's viper venom (RVV-NGFa) shows high affinity binding to TrkA receptor expressed in breast cancer cells: Application of fluorescence labeled RVV-NGFa in the clinical diagnosis of breast cancer.

Nerve growth factor (NGF) is a minor and neglected component of snake venom. Present study describes the purification and characterization of a NGF isoform (RVV-NGFa) from Indian Russell's viper venom (RVV). RVV-NGFa showed a protonated molecular ion [MH+] at m/z 17388.725 Da. The RVV-NGFa induced neuritogenesis in PC-12 cells but did not show cytotoxicity in mammalian cells, hemolytic activity, platelet modulation, and interference in blood coagulation system which are the characteristic pharmacological properties of RVV. By ELISA and immunofluorescence microplate reader assay, the RVV-NGFa showed appreciable binding to TrkA receptor expressed in breast cancer MDA-MB-231 and MCF-7 cells; nevertheless, pre-incubation of cells with anti-TrkA (and not TrkB or TrkC) or anti-p75NTR antibody significantly decreased (p < 0.05) this binding. The RVV-NGFa demonstrated insignificant binding with non-cancerous cells (HEK-293, L6) lacking TrkA receptor. The binding of RVV-NGFa to TrkA receptor of breast cancer cells resulted in internalization of ligand (RVV-NGFa)-receptor (TrkA) complex to cell cytoplasm in a time-dependent manner. The spectrofluorometric study demonstrated an interaction between RVV-NGFa and cytosolic domain of the purified TrkA receptor. The fluorescence (FITC)-tagged RVV-NGFa depicted a strong fluorescence signal that was observed under a fluorescence microscope and determined by fluorescence microplate reader assay post binding to breast cancer cells; but no fluorescence signal was detected after incubating FITC-RVV-NGFa with non-cancerous L6 and HEK-293 cells. The clinical application of FITC/fluorescence nanoparticle tagged RVV-NGFa for the ex vivo and in vivo diagnosis of breast cancer is highly promising.

Transcriptomic, proteomic, and biochemical analyses reveal a novel neuritogenesis mechanism of Naja naja venom α-elapitoxin post binding to TrkA receptor of rat pheochromocytoma cells.

This is the first report showing unique neuritogenesis potency of Indian Cobra N. naja venom long-chain α-neurotoxin (Nn-α-elapitoxin-1) exhibiting no sequence similarity to conventional nerve growth factor, by high-affinity binding to its tyrosine kinase A (TrkA) receptor of rat pheochromocytoma (PC-12) cells without requiring low-affinity receptor p75NTR. The binding residues between Nn-α-elapitoxin-1 and mammalian TrkA receptor are predicted by in silico analysis. This binding results in a time-dependent internalization of TrkA receptor into the cytoplasm of PC-12 cells. The transcriptomic analysis has demonstrated the differential expression of 445 genes; 38 and 32 genes are up-regulated and down-regulated, respectively in the PC-12 cells post-treatment with Nn-α-elapitoxin-1. Global proteomic analysis in concurrence with transcriptomic data has also demonstrated that in addition to expression of a large number of common intracellular proteins in the control and Nn-α-elapitoxin-1-treated PC-12 cells, the latter cells also showed the expression of uniquely up-regulated and down-regulated intracellular proteins involved in diverse cellular functions. Altogether, the data from transcriptomics, proteomics, and inhibition of downstream signaling pathways by specific inhibitors, and the immunoblot analysis of major regulators of signaling pathways of neuritogenesis unambiguously demonstrate that, similar to mouse 2.5S-nerve growth factor, the activation of mitogen activated protein kinase/extracellular signal-regulated kinase is the major signaling pathway for neuritogenesis by Nn-α-elapitoxin-1. Nonetheless, fibroblast growth factor signaling and heterotrimeric G-protein signaling pathways were found to be uniquely expressed in Nn-α-elapitoxin-1-treated PC-12 cells and not in mouse 2.5S-nerve growth factor -treated cells. The TrkA binding region of Nn-α-elapitoxin-1 may be developed as a peptide-based drug prototype for the treatment of major central neurodegenerative diseases. Read the Editorial Highlight for this article on page 599.

Ricinus communis L. fruit extract inhibits migration/invasion, induces apoptosis in breast cancer cells and arrests tumor progression in vivo.

Medicinal plant-based therapies can be important for treatment of cancer owing to high efficiency, low cost and minimal side effects. Here, we report the anti-cancer efficacy of Ricinus communis L. fruit extract (RCFE) using estrogen positive MCF-7 and highly aggressive, triple negative MDA-MB-231 breast cancer cells. RCFE induced cytotoxicity in these cells in dose and time-dependent manner. It also demonstrated robust anti-metastatic activity as it significantly inhibited migration, adhesion, invasion and expression of matrix metalloproteinases (MMPs) 2 and 9 in both cell lines. Further, flow cytometry analysis suggested RCFE-mediated induction of apoptosis in these cells. This was supported by attenuation of anti-apoptotic Bcl-2, induction of pro-apoptotic Bax and caspase-7 expressions as well as PARP cleavage upon RCFE treatment. RCFE (0.5 mg/Kg body weight) treatment led to significant reduction in tumor volume in 4T1 syngeneic mouse model. HPLC and ESI-MS analysis of active ethyl acetate fraction of RCFE detected four compounds, Ricinine, p-Coumaric acid, Epigallocatechin and Ricinoleic acid. Individually these compounds showed cytotoxic and migration-inhibitory activities. Overall, this study for the first time demonstrates the anti-cancer efficacy of the fruit extract of common castor plant which can be proposed as a potent candidate for the treatment of breast cancer.

Antiatherogenic Roles of Dietary Flavonoids Chrysin, Quercetin, and Luteolin.

Cardiovascular diseases (CVDs) are the commonest cause of global mortality and morbidity. Atherosclerosis, the fundamental pathological manifestation of CVDs, is a complex process and is poorly managed both in terms of preventive and therapeutic intervention. Aberrant lipid metabolism and chronic inflammation play critical roles in the development of atherosclerosis. These processes can be targeted for effective management of the disease. Although managing lipid metabolism is in the forefront of current therapeutic approaches, controlling inflammation may also prove to be crucial for an efficient treatment regimen of the disease. Flavonoids, the plant-derived polyphenols, are known for their antiinflammatory properties. This review discusses the possible antiatherogenic role of 3 flavonoids, namely, chrysin, quercetin, and luteolin primarily known for their antiinflammatory properties.

Daboxin P, a Major Phospholipase A2 Enzyme from the Indian Daboia russelii russelii Venom Targets Factor X and Factor Xa for Its Anticoagulant Activity.

In the present study a major protein has been purified from the venom of Indian Daboia russelii russelii using gel filtration, ion exchange and Rp-HPLC techniques. The purified protein, named daboxin P accounts for ~24% of the total protein of the crude venom and has a molecular mass of 13.597 kDa. It exhibits strong anticoagulant and phospholipase A2 activity but is devoid of any cytotoxic effect on the tested normal or cancerous cell lines. Its primary structure was deduced by N-terminal sequencing and chemical cleavage using Edman degradation and tandem mass spectrometry. It is composed of 121 amino acids with 14 cysteine residues and catalytically active His48 -Asp49 pair. The secondary structure of daboxin P constitutes 42.73% of α-helix and 12.36% of ß-sheet. It is found to be stable at acidic (pH 3.0) and neutral pH (pH 7.0) and has a Tm value of 71.59 ± 0.46°C. Daboxin P exhibits anticoagulant effect under in-vitro and in-vivo conditions. It does not inhibit the catalytic activity of the serine proteases but inhibits the activation of factor X to factor Xa by the tenase complexes both in the presence and absence of phospholipids. It also inhibits the tenase complexes when active site residue (His48) was alkylated suggesting its non-enzymatic mode of anticoagulant activity. Moreover, it also inhibits prothrombinase complex when pre-incubated with factor Xa prior to factor Va addition. Fluorescence emission spectroscopy and affinity chromatography suggest the probable interaction of daboxin P with factor X and factor Xa. Molecular docking analysis reveals the interaction of the Ca+2 binding loop; helix C; anticoagulant region and C-terminal region of daboxin P with the heavy chain of factor Xa. This is the first report of a phospholipase A2 enzyme from Indian viper venom which targets both factor X and factor Xa for its anticoagulant activity.