The present work aims at investigating the mechanism of action of the Rb9 peptide, which contains the VCDR 3 sequence of anti-sodium-dependent phosphate transport protein 2B (NaPi2B) monoclonal antibody RebMab200 and displayed antitumor properties. Short peptides corresponding to the hypervariable complementarity-determining regions (CDRs) of immunoglobulins have been associated with antimicrobial, antiviral, immunomodulatory and antitumor activities regardless of the specificity of the antibody. We have shown that the CDR derived peptide Rb9 induced substrate hyperadherence, inhibition of cell migration and matrix invasion in melanoma and other tumor cell lines.
View Article and Find Full Text PDFNatural monoterpenes were isolated from the essential oil of Piper cernuum Vell. (Piperaceae) leaves. The crude oil and the individual monoterpenes were tested for cytotoxicity in human tumor cell lineages and B16F10-Nex2 murine melanoma cells.
View Article and Find Full Text PDFParacoccidioidomycosis (PCM), caused by Paracoccidioides species, is the main cause of death due to systemic mycoses in Brazil and other Latin American countries. Therapeutic options for PCM and other systemic mycoses are limited and time-consuming, and there are high rates of noncompliance, relapses, toxic side effects, and sequelae. Previous work has shown that the cyclopalladated 7a compound is effective in treating several kinds of cancer and parasitic Chagas disease without significant toxicity in animals.
View Article and Find Full Text PDFFractionation of the MeOH extract from leaves of Piper cernuum Vell. (Piperaceae) afforded six phenylpropanoid derivatives: 3',4'-dimethoxydihydrocinnamic acid (1), piplaroxide (2), methyl 4'-hydroxy-3',5'-dimethoxy cinnamate (3), 3',4',5'-trimethoxydihydrocinnamic acid (3), dihydropiplartine (5), and piplartine (6). The structures of isolated metabolites were characterized by NMR and MS spectral data analysis.
View Article and Find Full Text PDFObjective: Homer1a is a protein that regulates metabotropic glutamate receptors involved in neural plasticity processes. Recently, we demonstrated that Homer1a mRNA is enhanced after pilocarpine-induced status epilepticus. Here, we investigated whether a single acute seizure triggered by means of pentylenetetrazole (PTZ) injection or maximal electroshock (MES) stimulation (2 different seizure models) would alter Homer1a expression in the hippocampus.
View Article and Find Full Text PDFPurpose: The antitumor activity of Kielmeyera coriacea (Clusiaceae), a medicinal plant used in the treatment of parasitic, as well as fungal and bacterial infections by the Brazilian Cerrado population, was investigated.
Methods: A chloroform extract (CE) of K. coriacea was tested in the murine melanoma cell line (B16F10-Nex2) and a panel of human tumor cell lines.
Context: Nectandra (Lauraceae) species have been used in folk medicine as an antidiarrheal, analgesic, antifungal, etc., and have many pharmacological proprieties.
Objective: Investigation of the chemical composition and cytotoxicity of essential oil from Nectandra leucantha Nees & Mart.
Background: Pyrostegia venusta (Ker. Gawl.) Miers (Bignoniacea) is a medicinal plant from the Brazilian Cerrado used to treat leucoderma and common diseases of the respiratory system.
View Article and Find Full Text PDFShort synthetic peptides corresponding to sequences of complementarity-determining regions (CDRs) from different immunoglobulin families have been shown to induce antimicrobial, antiviral and antitumor activities regardless of the specificity of the original monoclonal antibody (mAb). Presently, we studied the in vitro and in vivo antitumor activity of synthetic peptides derived from conserved CDR sequences of different immunoglobulins against human tumor cell lines and murine B16F10-Nex2 melanoma aiming at the discovery of candidate molecules for cancer therapy. Four light- and heavy-chain CDR peptide sequences from different antibodies (C36-L1, HA9-H2, 1-H2 and Mg16-H2) showed cytotoxic activity against murine melanoma and a panel of human tumor cell lineages in vitro.
View Article and Find Full Text PDFThe increased incidence, high rates of mortality and few effective means of treatment of malignant melanoma, stimulate the search for new anti-tumor agents and therapeutic targets to control this deadly metastatic disease. In the present work the antitumor effect of arazyme, a natural bacterial-derived metalloprotease secreted by Serratia proteomaculans, was investigated. Arazyme significantly reduced the number of pulmonary metastatic nodules after intravenous inoculation of B16F10 melanoma cells in syngeneic mice.
View Article and Find Full Text PDFThe search for new compounds that induce p53-independent apoptosis is the focus of many studies in cancer biology because these compounds could be more specific and would overcome chemotherapy resistance. In this study, we evaluated the in vitro antitumour activity of a Biphosphinic Palladacycle Complex (BPC) and extended preclinical studies to an in vivo model. Saos-2 cells, a p53-null human osteosarcoma drug-resistant cell line, were treated with BPC in the presence or absence of a cathepsin B inhibitor and a calcium chelator (CA074 and BAPTA-AM, respectively), and several parameters related to apoptosis were evaluated.
View Article and Find Full Text PDFThe Wilms tumor protein 1 (WT1) transcription factor has been associated in malignant melanoma with cell survival and metastasis, thus emerging as a candidate for targeted therapy. A lysine-arginine rich peptide, WT1-pTj, derived from the ZF domain of WT1 was evaluated as an antitumor agent against A2058 human melanoma cells and B16F10-Nex2 syngeneic murine melanoma. Peptide WT1-pTj quickly penetrated human melanoma cells and induced senescence, recognized by increased SA-β-galactosidase activity, enhanced transcriptional activity of p53, and induction of the cell cycle inhibitors p21 and p27.
View Article and Find Full Text PDFBiochimie
April 2014
Breast cancer is the world's leading cause of death among women. This situation imposes an urgent development of more selective and less toxic agents. The use of natural molecular fingerprints as sources for new bioactive chemical entities has proven to be a quite promising and efficient method.
View Article and Find Full Text PDFCasearia sylvestris (Salicaceae), popularly known as "guaçatonga", is a plant widely used in folk medicine to treat various diseases, including cancer. The present work deals with the chemical composition as well as the cytotoxic evaluation of its essential oil, its main constituent and derivatives. Thus, the crude essential oil from leaves of C.
View Article and Find Full Text PDFBackground: The fungal cell wall is a complex and dynamic outer structure. In pathogenic fungi its components interact with the host, determining the infection fate. The present work aimed to characterize cell wall lipids from P.
View Article and Find Full Text PDFThis work reports the chemical composition and cytotoxic evaluation of the essential oils from three different samples of the leaves of Porcelia macrocarpa R. E. Fries (Annonaceae).
View Article and Find Full Text PDFParacoccidioides brasiliensis and Paracoccidioides lutzii are thermodimorphic species that cause paracoccidioidomycosis. The cell wall is the outermost fungal organelle to form an interface with the host. A number of host effector compounds, including immunologically active molecules, circulate in the plasma.
View Article and Find Full Text PDFAims: S-nitrosylation of Cys118 is a redox-based mechanism for Ras activation mediated by nitric oxide (NO) at the plasma membrane.
Results: Ras signaling pathway stimulation by 50 and/or 100 μM of S-nitrosoglutathione (GSNO) causes proliferation of HeLa cells. Proliferation was not observed in HeLa cells overexpressing non-nitrosatable H-Ras(C118S).
Context: In folk medicine, Schinus terebinthifolius Raddi (Anacardiaceae), has been used as a remedy for ulcers, respiratory problems, wounds, rheumatism, gout, diarrhea, skin ailments and arthritis, as well as to treat tumors and leprosy.
Objective: To investigate the chemical composition and cytotoxicity of essential oil from leaves of S. terebinthifolius as well as the identification of active compounds from this oil.
Background: Fungal extracellular vesicles are able to cross the cell wall and transport molecules that help in nutrient acquisition, cell defense, and modulation of the host defense machinery.
Methodology/principal Findings: Here we present a detailed lipidomic analysis of extracellular vesicles released by Paracoccidioides brasiliensis at the yeast pathogenic phase. We compared data of two representative isolates, Pb3 and Pb18, which have distinct virulence profiles and phylogenetic background.