Antigenotoxicity and antimutagenicity of lycopene in HepG2 cell line evaluated by the comet assay and micronucleus test

Epidemiological studies have provided evidence that high consumption of tomatoes effectively reduces the risk of reactive oxygen species (ROS)-mediated diseases such as cancer. Tomatoes are rich sources of lycopene, a potent singlet oxygen-quenching carotenoid. In addition to its antioxidant properties, lycopene shows an array of biological effects including antimutagenic and anticarcinogenic activities. In the present study, the chemopreventive action of lycopene was examined on DNA damage and clastogenic or aneugenic effects of H2O2 and n-nitrosodiethylamine (DEN) in the metabolically competent human hepatoma cell line (HepG2 cells). Lycopene at concentrations of 10. 25, and 50 mu M, was tested under three protocols: before, simultaneously, and after treatment with the mutagen, using the comet and micronucleus assays. Lycopene significantly reduced the genotoxicity and mutagenicity of H2O2 in all of the conditions tested. For DEN, significant reductions of primary DNA damage (comet assay) were detected when the carotenoid (all of the doses) was added in the cell culture medium before or simultaneously with the mutagen. In the micronucleus test, the protective effect of lycopene was observed only when added prior to DEN treatment. In conclusion, our results suggest that lycopene is a suitable agent for preventing chemically-induced DNA and chromosome damage. (C) 2007 Elsevier Ltd. All rights reserved.

Human breast tumor slices as an alternative approach to cell lines to individualize research for each patient

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

Cell-mediated immune response to Leishmania chagasi experimental infection of BALB/c immunosuppressed mice

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

In vitro cultivation of canine multipotent mesenchymal stromal cells on collagen membranes treated with hyaluronic acid for cell therapy and tissue regeneration

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

Viability and cell cycle analysis of equine fibroblasts cultured in vitro

This experiment aimed to study equine fibroblasts in culture analyzing and the cell cycle and viability of cells pre- and post-freezing. Skin fragments were obtained from 6 horses and cultured in DMEM high glucose + 10% FCS in 5% CO(2) until the beginning of confluence. Two passages were performed before freezing. Cells subjected to serum starvation (0.5% FCS) were analyzed for viability and cell cycle at 24, 48, 72, 96, 120, 144 and 168 h of culture. For the confluent groups, cells were analyzed at the moment they achieved confluence. Cellular viability was assisted with Hoescht 33342 and propidium iodide. The analysis of apoptosis/necrosis and cell cycle was performed using a flow cytometer (FACS Calibur BD(A (R))) after staining the cells with annexin V and propidium iodide. Both optical microscopy and flow cytometry confirmed that cellular viability was similar for serum starvation and confluent groups (average 84%). Similarly, both methods were efficient to synchronize the cell cycle before freezing. However, after thawing, serum starvation, for more than 24 h, was superior to culture for synchronizing cells in G0/G1 (69% x 90%). The results of this experiment indicate that equine fibroblasts can be efficiently cultured after thawing.

Rabies neutralizing antibody detection by indirect immunperoxidase serum neutralization assay performed on chicken embryo related cell line

The aim of this study was to evaluate the indirect immunoperoxidase virus neutralization (IPVN) and mouse neutralization test (MNT) to detect antibodies against rabies virus from vaccinated dogs and cattle. The IPVN was set up for the ability to measure 0.5 International Units/ml (IU) of antibody required by the World Health Organization and the Office International des Epizooties as the minimum response for proof of rabies immunization. IPVN was developed and standardized in chicken embryo related (CER) cell line when 141 dog and 110 cattle sera were applied by serial five-fold dilutions (1:5, 1:25, 1:125) as well as the positive and negative reference controls, all added in four adjacent wells, of 96-well microplates. A 50 µl amount of CVS32 strain dilution containing 50-200 TCID50/ml was mixed to each serum dilution, and after 90 min 50 µl of 3 x 10(5) cells/mlcell suspension added to each well. After five days of incubation, the monolayers were fixed and the IPVN test performed. The correlation coefficient between the MNT and IPVN performed in CER cells was r = 0.9949 for dog sera (n = 100) and r = 0.9307 for cattle sera (n = 99), as well as good specificity (94.7%), sensitivity (87.5%), and agreement (96.6%) were also obtained. IPVN technique can adequately identify vaccinated and unvaccinated animals, even from low-responding vaccinated animals, with the advantage of low cost and faster then MNT standard test.

Diminished CD4+/CD25+T cell and increased IFN-gamma levels occur in dogs vaccinated with Leishmune (R) in an endemic area for visceral leishmaniasis

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

Mineral trioxide aggregate stimulates macrophages and mast cells to release neutrophil chemotactic factors: role of IL-1 beta, MIP-2 and LTB4

Objective. In the present study, the role of macrophages and mast cells in mineral trioxide aggregate (MTA)-induced release of neutrophil chemotactic factor was investigated.Study design. MTA suspension (50 mg/mL) was plated over inserts on macrophages or mast cells for 90 minutes. Untreated cells served as controls. Cells were washed and cultured for 90 minutes in RPMI without the stimuli. Macrophages and mast cell supernatants were injected intraperitoneally (0.5 mL/cavity), and neutrophil migration was assessed 6 hours later. In some experiments, cells were incubated for 30 minutes with dexamethasone (DEX, 10 mu M/well), BWA4C (BW, 100 mu M/well) or U75302 (U75, 10 mu M/well). The concentration of Leukotriene B-4 (LTB4) in the cell-free supernatant from mast cells and macrophage culture was measured by ELISA.Results. Supernatants from MTA-stimulated macrophages and mast cells caused neutrophil migration. The release of neutrophil chemotactic factor by macrophages and mast cells was significantly inhibited by DEX, BW, or U75. Macrophages and mast cells expressed mRNA for interleukin-1 (IL-1)beta and macrophage inflammatory protein-2 (MIP-2) and the pretreatment of macrophages and mast cells with DEX, BW, or U75 significantly altered IL-1 beta and MIP-2 mRNA expression. LTB4 was detected in the MTA-stimulated macrophage supernatant but not mast cells.Conclusions. MTA-induces the release of neutrophil chemotactic factor substances from macrophages and mast cells with participation of IL-1 beta, MIP-2, and LTB4. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010; 109: e135-e142)

Trans-enamel and trans-dentinal cytotoxic effects of a 35% H2O2 bleaching gel on cultured odontoblast cell lines after consecutive applications

To evaluate the trans-enamel and trans-dentinal cytotoxic effects of a 35% H2O2 bleaching gel on an odontoblast-like cell lines (MDPC-23) after consecutive applications.Fifteen enamel/dentine discs were obtained from bovine central incisor teeth and placed individually in artificial pulp chambers. Three groups (n = 5 discs) were formed according to the following enamel treatments: G1: 35% H2O2 bleaching gel (15 min); G2: 35% H2O2 bleaching gel (15 min) + halogen light (20 s); G3: control (no treatment). After repeating the treatments three consecutive times, the extracts (culture medium + gel components that had diffused through enamel/dentine discs) in contact with the dentine were collected and applied to previously cultured MDPC-23 cells (50 000 cells cm(-2)) for 24 h. Cell metabolism was evaluated by the MTT assay and data were analysed statistically (alpha = 5%; Kruskal-Wallis and Mann-Whitney U-test). Cell morphology was analysed by scanning electron microscopy.Cell metabolism decreased by 92.03% and 82.47% in G1 and G2 respectively. G1 and G2 differed significantly (P < 0.05) from G3. Regardless of halogen light activation, the application of the bleaching gel on the cultured odontoblast-like cells caused significantly more severe cytotoxic effects than those observed in the nontreated control group. In addition, significant morphological cell alterations were observed in G1 and G2.After three consecutive applications of a 35% H2O2 bleaching agent, the diffusion of the gel components through enamel and dentine caused severe toxic effects to cultured pulp cells.

Mechanical and biological characterization of resin-modified glass-ionomer cement containing doxycycline hyclate

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

Nutritional stress enhances cell viability of odontoblast-like cells subjected to low level laser irradiation

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

Inhibitory effect of essential oils against Lactobacillus rhamnosus and starter culture in fermented milk during its shelf-life period

The use of essential oils in foods has attracted great interest, due to their antagonistic action against pathogenic microorganisms. However, this action is undesirable for probiotic foods, as products containing Lactobacillus rhamnosus. The aim of the present study was to measure the sensitivity profile of L. rhamnosus and a yogurt starter culture in fermented milk, upon addition of increasing concentrations of cinnamon, clove and mint essential oils. Essential oils were prepared by steam distillation, and chemically characterised by gas chromatography-mass spectrometry (GC-MS) and determination of density. Survival curves were obtained from counts of L. rhamnosus and the starter culture (alone and in combination), upon addition of 0.04% essential oils. In parallel, titratable acidity was monitored over 28 experimental days. Minimum inhibitory concentration values, obtained using the microdilution method in Brain Heart Infusion medium, were 0.025, 0.2 and 0.4% for cinnamon, clove and mint essential oils, respectively. Cinnamon essential oil had the highest antimicrobial activity, especially against the starter culture, interfering with lactic acid production. Although viable cell counts of L. rhamnosus were lower following treatment with all 3 essential oils, relative to controls, these results were not statistically significant; in addition, cell counts remained greater than the minimum count of 10(8)CFU/mL required for a product to be considered a probiotic. Thus, although use of cinnamon essential oil in yogurt makes starter culture fermentation unfeasible, it does not prevent the application of L. rhamnosus to probiotic fermented milk. Furthermore, clove and mint essential oil caused sublethal stress to L. rhamnosus.

A thin layer electrochemical cell for disinfection of water contaminated with Staphylococcus aureus

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

Effects of culture conditions on the production of inulinase by Kluyveromyces marxianus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Microscopic Evidences That Bone Marrow Mononuclear Cell Treatment Improves Sciatic Nerve Regeneration After Neurorrhaphy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)