Correlation among Antioxidant, Antimicrobial, Hemolytic, and Antiproliferative Properties of Leiothrix spiralis Leaves Extract

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Chemical and Antidiarrheal Studies of Plinia cauliflora

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Suppression of TNF- induced NFB activity by gallic acid and its semi-synthetic esters: possible role in cancer chemoprevention

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genotoxicity and mutagenicity of water contaminated with tannery effluents, as evaluated by the micronucleus test and comet assay using the fish Oreochromis niloticus and chromosome aberrations in onion root-tips

Cytotoxicity of metals is important because some metals are potential mutagens able to induce tumors in humans and experimental animals. Chromium can damage DNA in several ways, including DNA double strand breaks (DSBs) which generate chromosomal aberrations, micronucleus formation, sister chromatid exchange, formation of DNA adducts and alterations in DNA replication and transcription. In our study, water samples from three sites in the Córrego dos Bagres stream in the Franca municipality of the Brazilian state of São Paulo were subjected to the comet assay and micronucleus test using erythrocytes from the fish Oreochromis niloticus. Nuclear abnormalities of the erythrocytes included blebbed, notched and lobed nuclei, probably due to genotoxic chromium compounds. The greatest comet assay damage occurred with water from a chromium-containing tannery effluent discharge site, supporting the hypothesis that chromium residues can be genotoxic. The mutagenicity of the water samples was assessed using the onion root-tip cell assay, the most frequent chromosomal abnormalities observed being: c-metaphases, stick chromosome, chromosome breaks and losses, bridged anaphases, multipolar anaphases, and micronucleated and binucleated cells. Onion root-tip cell mutagenicity was highest for water samples containing the highest levels of chromium.

Characterization of PVDF/HAP composites for medical applications

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Synthesis, spectroscopic characterization and biological analysis of a new palladium(II) complex with methionine sulfoxide

A new palladium(II) complex with methionine sulfoxide was synthesized and characterized by a set of chemical and spectroscopic techniques. Elemental and mass spectrometry analyses of the solid complex fit to the composition [Pd(C5H10NO3S)(2)]center dot H2O. C-13 NMR, [H-1-N-15] NMR and infrared spectra indicate coordination of the amino acid to Pd(II) through the carboxylate and amino groups in a square planar geometry. The complex is soluble in water.Biological activity was evaluated by cytotoxic analysis using HeLa cells. Determination of cell death was assessed using a tetrazolium salt colorimetric assay, which reflects the cells viability. After incubation for 48 h, 20% of cell death was achieved at a concentration of 200 mu mol L-1 of the complex. (c) 2006 Elsevier B.V. All rights reserved.

Leukotoxic activity of Actinobacillus actinomycetemcomitans isolated from Brazilian periodontal patients

The leukotoxic activity of 31 Actinobacillus actinomycetemcomitans isolates from Brazilian periodontal patients [nine from Localized Juvenile Periodontitis (LJP) patients, 22 from patients with AIDS-associated Necrotizing Ulcerative Periodontitis (AIDS/NUP)], and from the reference strain A. actinomycetemcomitans ATCC43718, were analyses for their cytotoxicity on human monocytes. A cytotoxicity inhibitory assay of the isolate P35 and the reference strain ATCC 43718 with sera from ten LJP patients and ten healthy subjects was also performed and leukotoxin reactivity was evaluated with serum from rabbits immune to leukotoxin from A. actinomycetemcomitans ATCC 43718. The cytotoxicity results were not statistically different among groups of A. actinomycetemcomitans isolates from LJP and AIDS/NUP patients, but the individual analysis of each isolate showed two isolates (P24 and P35) from LJP patients with high leukotoxic activity (P<0.05). Also, a high leucotoxic inhibitory effect with LJP patients' sera compared with healthy subjects with sonic extract from isolate P35 (P<0.05) and the reactivity of rabbit antiserum to leukotoxin were observed. Both leukotoxic and non-leukotoxic activity is more frequent in PJL than AIDS/NUP patients. Even though A. actinomycetemcomitans exhibits leukotoxic activity, there is an immune response to the leucotoxin in LJP patients. (C) 2000 Academic Press.

Biocompatibility of denture base acrylic resins evaluated M culture of L929 cells. Effect of polymerisation cycle and postpoymerisation treatments

Objective: the purpose of this study was to evaluate the effect of two post-polymerisation treatments and different cycles of polymerisation on the cytotoxicity of two denture base resins.Materials and methods: the resins tested were Lucitone 550 and QC 20. Discs of resins were fabricated following the manufacturer's instructions. Lucitone 550 was processed by long cycle or short cycle. The resin QC 20 was processed by reverse cycle or normal cycle. The specimens were divided into groups: (i) post-polymerised in microwave for 3 min at 500 W; (ii) post-polymerised in water-bath at 55 degrees C for 60 min and (iii) without post-polymerisation. Eluates were prepared by placing three discs into a sterile glass vial with 9 ml of Eagle's medium and incubated at 37 degrees C for 24 hours. L929 cells were seeded into 96 3 well culture plates and DNA synthesis was assessed by H-thymidine incorporation assay.Results: the results were submitted to two-way ANOVA and Tukey HSD test. QC 20 specimens polymerised by the normal cycle and submitted to microwave post-polymerisation were graded as moderately cytotoxic. Similar results were observed for Lucitone 550 processed by long cycle without post-polymerisation. The other experimental groups were graded as not cytotoxic. After water-bath post-polymerisation, specimens of Lucitone 550 processed by long cycle produced significantly lower inhibition of DNA synthesis than the other groups.Conclusion: the long cycle increased the cytotoxicity of Lucitone 550 and water-bath post-polymerisation reduced the cytotoxicity of Lucitone 550 processed by long cycle.

Synthesis and X-ray structure of the dinuclear platinum(II) complex with saccharin {K[Pt(sac)(3)(H2O)] center dot H2O}(2): Studies on its antiproliferative activity in aqueous solution

Synthesis and X-ray structure of a dinuclear platinum(II) complex with the ligand saccharin(sac) are described. The structure shows two approximately square-planar platinum centers. Each platinum atom is coordinated to one water molecule and three N-bonded saccharinate ligands. The two centers are linked through two potassium atoms. Each potassium atom interacts with six oxygen atoms from hydration and coordinated water molecules and from carbonyl and sulfonate groups of the ligands. It is suggested that, in aqueous solution, the dimeric structure of the complex is dissociated and the monomeric species K[Pt(sac)(3)(H2O)] is formed. The complex was dissolved in water and submitted to in vitro cytotoxic analyses using HeLa cells (human cervix cancer). It was shown that the monomeric complex elicited a potent cytotoxic activity when compared to the vehicle-treated cells. The IC50 value for the monomeric complex is 6.8 mu M, a little bit higher than that obtained for cisplatin. (c) 2007 Elsevier B.V. All rights reserved.

Initial Development and Characterization of PLGA Nanospheres Containing Ropivacaine

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

BIOACTIVE AND OTHER PIPERIDINE ALKALOIDS FROM CASSIA-LEPTOPHYLLA

Four new piperidine alkaloids, leptophyllin A (4), 3-acetylleptophyllin A (5), leptophyllin B (8), and (-)-spectaline (1), and 3 known piperidine alkaloids, (-)-spectalinine (2), canavaline (3), and iso-6-canavaline (7), were isolated by a bioassay-guided fractionation of a leaf extract of Cassia leptophylla. The alkaloids 1 - 3 were active in a mechanism-based DNA-modifying yeast assay and 2 was moderately active in Vero monkey and Chinese hamster ovary cell cytotoxicity assays.

Dehydromonocrotaline inhibits mitochondrial complex 1. A potential mechanism accounting for hepatotoxicity of monocrotaline

Monocrotaline is a pyrrolizidine alkaloid present in plants of the Crotalaria species, which causes cytotoxicity and genotoxicity, including hepatotoxicity in animals and humans. It is metabolized by cytochrome P-450 in the liver to the alkylating agent dehydromonocrotaline. We evaluated the effects of monocrotaline and its metabolite on respiration, membrane potential and ATP levels in isolated rat liver mitochondria, and on respiratory chain complex I NADH oxidase activity in submitochondrial particles. Dehydromonocrotaline, but not the parent compound, showed a concentration-dependent inhibition of glutamate/malate-supported state 3 respiration (respiratory chain complex 1), but did not affect succinate-supported respiration (complex II). Only dehydromonocrotaline dissipated mitochondrial membrane potential, depleted ATP, and inhibited complex I NADH oxidase activity (IC50 = 62.06 mu M) through a non-competitive type of inhibition (K-I = 8.1 mu M). Therefore, dehydromonocrotaline is an inhibitor of the activity of respiratory chain complex I NADH oxidase, an action potentially accounting for the well-documented monocrotaline's hepatotoxicity to animals and humans. The mechanism probably involves change of the complex I conformation resulting from modification of cysteine thiol groups by the metabolite. (c) 2007 Elsevier Ltd. All rights reserved.

Mutagenic and cytotoxic activity of an isocoumarin (Paepalantine) isolated from Paepalanthus vellozioides

A new isocoumarin with antimicrobial activity was isolated from Paepalanthus vellozioides (a native Brazilian plant) and called paepalantine. This study was carried out to assess the mutagenic activity of this new agent in assays with Salmonella typhimurium TA100, TA98, and TA102 and in Chinese hamster ovary (CHO) cell cultures, as well as cytotoxicity to McCoy cells. Paepalantine caused a significant dose-dependent increase in the frequency of revertants in the three strains used in the assay, both with and without S9 mix, in concentrations varying from 2 to 128 mu g/ plate. The mutagenicity was confirmed in assays with CHO cells treated in the G(1), S, and G(2) phases of the cell cycle. There was an increase in the chromosomal aberration frequency, mainly in the G(2) phase. Furthermore, the mitotic index of the treated cultures (40,80, and 160 mu g/ml) was significantly lower, indicating cytotoxicity. The midpoint cytotoxicity values to McCoy cells by the neutral red (NR) and microculture tetrazolium (MTT) techniques resulted in a NR50, and MTT50 of 30 and 38 mu g/ml, respectively. Alterations to the paepalantine structure are suggested to reduce its mutagenic and cytotoxic activity in investigations for its antineoplasic potential (C) 1997 Wiley-Liss, Inc.

In vitro prostate cancer cell growth inhibition by Brazilian plant extracts

In the present study, 1220 plant extracts obtained from 352 plants belonging to 73 families that grow in the Amazon and Atlantic rain forests were screened for cytotoxicity against PC-3 prostate cancer cell lines. Extracts were tested in the single dose of 100 mu g/mL. Activity was observed in 17 aqueous or organic extracts belonging to Annonaceae, Apocynaceae, Araceae, Capparaceae, Commelinaceae, Flacourtiaceae, Lecythiclaceae, Leguminosae, Passifloraceae, Rutaceae, and Violaceae.

Lithium thiazolidine-4-carboxylate: Synthesis, spectroscopic characterization and preliminary in vitro cytotoxic studies in human HeLa cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)