Cytotoxic, biochemical and genotoxic effects of biodiesel produced by different routes on ZFL cell line

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Elevated micronucleus frequency in patients with type 2 diabetes, dyslipidemia and periodontitis

The over-production of reactive oxygen species (ROS) can cause oxidative damage to a large number of molecules, including DNA, and has been associated with the pathogenesis of several disorders, such as diabetes mellitus (DM), dyslipidemia and periodontitis (PD). We hypothesise that the presence of these diseases could proportionally increase the DNA damage. The aim of this study was to assess the micronucleus frequency (MNF), as a biomarker for DNA damage, in individuals with type 2 DM, dyslipidemia and PD. One hundred and fifty patients were divided into five groups based upon diabetic, dyslipidemic and periodontal status (Group 1 - poor controlled DM with dyslipidemia and PD; Group 2 - well-controlled DM with dyslipidemia and PD; Group 3 - without DM with dyslipidemia and PD; Group 4 - without DM, without dyslipidemia and with PD; and Group 5 - without DM, dyslipidemia and PD). Blood analyses were carried out for fasting plasma glucose, HbA1c and lipid profile. Periodontal examinations were performed, and venous blood was collected and processed for micronucleus (MN) assay. The frequency of micronuclei was evaluated by cell culture cytokinesis-block MN assay. The general characteristics of each group were described by the mean and standard deviation and the data were submitted to the Mann-Whitney, Kruskal-Wallis, Multiple Logistic Regression and Spearman tests. The Groups 1, 2 and 3 were similarly dyslipidemic presenting increased levels of total cholesterol, low density lipoprotein cholesterol and triglycerides. Periodontal tissue destruction and local inflammation were significantly more severe in diabetics, particularly in Group 1. Frequency of bi-nucleated cells with MN and MNF, as well as nucleoplasmic bridges, were significantly higher for poor controlled diabetics with dyslipidemia and PD in comparison with those systemically healthy, even after adjusting for age, and considering Bonferroni's correction. Elevated frequency of micronuclei was found in patients affected by type 2 diabetes, dyslipidemia and PD. This result suggests that these three pathologies occurring simultaneously promote an additional role to produce DNA impairment. In addition, the micronuclei assay was useful as a biomarker for DNA damage in individuals with chronic degenerative diseases.

Synergistic Anti-Inflammatory Activity of the Antimicrobial Peptides Human Beta-Defensin-3 (hBD-3) and Cathelicidin (LL-37) in a Three-Dimensional Co-Culture Model of Gingival Epithelial Cells and Fibroblasts

Given the spread of antibiotic resistance in bacterial pathogens, antimicrobial peptides that can also modulate the immune response may be a novel approach for effectively controlling periodontal infections. In the present study, we used a three-dimensional (3D) co-culture model of gingival epithelial cells and fibroblasts stimulated with Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS) to investigate the anti-inflammatory properties of human beta-defensin-3 (hBD-3) and cathelicidin (LL-37) and to determine whether these antimicrobial peptides can act in synergy. The 3D co-culture model composed of gingival fibroblasts embedded in a collagen matrix overlaid with gingival epithelial cells had a synergistic effect with respect to the secretion of IL-6 and IL-8 in response to LPS stimulation compared to fibroblasts and epithelial cells alone. The 3D co-culture model was stimulated with non-cytotoxic concentrations of hBD-3 (10 and 20 mu M) and LL-37 (0.1 and 0.2 mu M) individually and in combination in the presence of A. actinomycetemcomitans LPS. A multiplex ELISA assay was used to quantify the secretion of 41 different cytokines. hBD-3 and LL-37 acted in synergy to reduce the secretion of GRO-alpha, G-CSF, IP-10, IL-6, and MCP-1, but only had an additive effect on reducing the secretion of IL-8 in response to A. actinomycetemcomitans LPS stimulation. The present study showed that hBD-3 acted in synergy with LL-37 to reduce the secretion of cytokines by an LPS-stimulated 3D model of gingival mucosa. This combination of antimicrobial peptides thus shows promising potential as an adjunctive therapy for treating inflammatory periodontitis.

Pyrostegia venusta heptane extract containing saturated aliphatic hydrocarbons induces apoptosis on B16F10-Nex2 melanoma cells and displays antitumor activity in vivo

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

Nanocomposites based on bacterial cellulose in combination with osteogenic growth peptide for bone repair: cytotoxic, genotoxic and mutagenic evaluations

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

Immediate and late analysis of dental pulp stem cells viability after indirect exposition to alternative in-office bleaching strategies

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

Cytotoxicity of dimethyl sulfoxide (DMSO) in direct contact with odontoblast-like cells

To evaluate the cytotoxicity of dimethyl sulfoxide (DMSO) on the repair-related activity of cultured odontoblast-like MDPC-23 cells. Methods Solutions with different concentrations of DMSO (0.05, 0.1, 0.3, 0.5 and 1.0 mM), diluted in culture medium (DMEM), were placed in contact with MDPC-23 cells (5 × 104 cells/cm2) for 24 h. Eight replicates (n = 8) were prepared for each solutions for the following methods of analysis: violet crystal dye for cell adhesion (CA), quantification of total protein (TP), alizarin red for mineralization nodules formation (MN) and cell death by necrosis (flow cytometry); while twelve replicates (n = 12) were prepared for viable cell number (Trypan Blue) and cell viability (MTT assay). Data were analyzed by ANOVA and Tukey or Kruskal–Wallis and Mann–Whitney's tests (p < 0.05). Results Cell viability, adhesion and percentage of cell death by necrosis were not affected by DMSO at any concentration, with no statistical significant difference among the groups. A significant reduction in total protein production was observed for 0.5 and 1.0 mM of DMSO compared to the control while increased mineralized nodules formation was seen only for 1.0 mM DMSO. Significance: DMSO caused no or minor cytotoxic effects on the pulp tissue repair-related activity of odontoblast-like cells.

Protective effect of sodium ascorbate on odontoblast-like cells MDPC-23 exposed to a bleaching agent

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

Transdentinal cytotoxicity of carbodiimide (EDC) and glutaraldehyde on odontoblast-like cells

Objective: To evaluate the transdentinal cytotoxicity of three different concentrations of carbodiimide (EDC) or 5% glutaraldehyde (GA) on MDPC-23 cells. Methods: Seventy 0.4-mm-thick dentin disks obtained from human molars were adapted to artificial pulp chambers. MDPC-23 cells were seeded on the pulpal surface of the disks. After 48 hours, the occlusal dentin was acid-etched and treated for 60 seconds with one of the following solutions (n=10): no treatment (negative control); 0.1 M, 0.3 M, or 0.5 M EDC; 5% GA; Sorensen buffer; or 29% hydrogen peroxide (positive control). Cell viability and morphology were assessed by methyltetrazolium assay and scanning electron microscopy (SEM), respectively. The eluates were collected after the treatments and applied on MDPC-23 seeded in a 24-well plate to analyze cell death, total protein (TP), and collagen production. The last two tests were performed 24 hours and seven days after the challenge. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests (p<0.05). Results: EDC at all test concentrations did not reduce cell viability, while 5% GA did increase cell metabolism. Cell death by necrosis was not elicited by EDC or 5% GA. At the 24-hour period, 0.3 M and 0.5 M EDC reduced TP production by 18% and 36.8%, respectively. At seven days, increased TP production was observed in all groups. Collagen production at the 24-hour period was reduced when 0.5 M EDC was used. After seven days, no difference was observed among the groups. SEM showed no alteration in cell morphology or number, except in the hydrogen peroxide group. Conclusions: Treatment of acid-etched dentin with EDC or GA did not cause transdentinal cytotoxic effects on odontoblast-like cells.

Green tea polyphenol epigallocatechin-3-gallate and cranberry proanthocyanidins act in synergy with cathelicidin (LL-37) to reduce the LPS-induced inflammatory response in a three-dimensional co-culture model of gingival epithelial cells and fibroblasts

Objectives: The human antimicrobial peptide cathelicidin (LL-37) possesses anti-inflammatory properties that may contribute to attenuating the inflammatory process associated with chronic periodontitis. Plant polyphenols, including those from cranberry and green tea, have been reported to reduce inflammatory cytokine secretion by host cells. In the present study, we hypothesized that A-type cranberry proanthocyanidins (AC-PACs) and green tea epigallocatechin-3-gallate (EGCG) act in synergy with LL-37 to reduce the secretion of inflammatory mediators by oral mucosal cells. Methods: A three-dimensional (3D) co-culture model of gingival epithelial cells and fibroblasts treated with non-cytotoxic concentrations of AC-PACs (25 and 50 mg/ml), EGCG (1 and 5 mg/ml), and LL-37 (0.1 and 0.2 mM) individually and in combination (AC-PACs + LL-37 and EGCG + LL-37) were stimulated with Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS). Multiplex ELISA assays were used to quantify the secretion of 54 host factors, including chemokines, cytokines, growth factors, matrix metalloproteinases (MMPs), and tissue inhibitors of metalloproteinases (TIMPs). Results: LL-37, AC-PACs, and EGCG, individually or in combination, had no effect on the regulation of MMP and TIMP secretion but inhibited the secretion of several cytokines. ACPACs and LL-37 acted in synergy to reduce the secretion of CXC-chemokine ligand 1 (GRO-a), granulocyte colony-stimulating factor (G-CSF), and interleukin-6 (IL-6), and had an additive effect on reducing the secretion of interleukin-8 (IL-8), interferon-g inducible protein 10 (IP-10), and monocyte chemoattractant protein-1 (MCP-1) in response to LPS stimulation. EGCG and LL-37 acted in synergy to reduce the secretion of GRO-a, G-CSF, IL-6, IL-8, and IP-10, and had an additive effect on MCP-1 secretion. Conclusion: The combination of LL-37 and natural polyphenols from cranberry and green tea acted in synergy to reduce the secretion of several cytokines by an LPS-stimulated 3D coculture model of oral mucosal cells. Such combinations show promising results as potential adjunctive therapies for treating inflammatory periodontitis.

Metabolism of L929 cells after contact with acrylic resins. Part 1: Acrylic denture base resins

The purpose of this study was to evaluate the effectiveness of complementary heat treatment and water storage in reducing cytotoxicity of acrylic resins denture bases used in Brazil by the MTT assay. Material and Methods: First, nine specimens were fabricated from metal matrix in the form of discs with 14 mm in diameter and 1.2 mm of thick. Immediately after making, 24 or 48 hours after storage in distilled water, the samples of heat-polymerized resins were divided into 3 groups (n = 3) according to the type of thermal treatment: Group 1: samples were individually exposed to microwave energy (500 W for 3 minutes); Group 2: samples were immersed in water at 550 C for 60 minutes; Group 3: samples did not receive heat treatment. To prepare the extracts, 3 samples of each group were placed into vials containing 3 mL of culture medium and stored at 37°C for 24 hours. L929 cells were used and the MTT assay was performed to analyze the cellular metabolism. Two-factor analysis of variance was used to detect significant among groups at 5% significance. Results: After statistical analysis, the materials were classified according to the cytotoxic effect: non-cytotoxic, slightly cytotoxic; moderately cytotoxic; and strongly cytotoxic. The results showed that the resins ranged from moderately cytotoxic to non-cytotoxic, but no statistically significant difference among experimental groups. Furthermore, the water storage and thermal treatments reduced the cytotoxicity of the resins. Conclusions: It was concluded that the resins studied are potentially toxic and that treatments can decrease their cytotoxicity.

Dose-Response and Time-Course of a-Tocoferol Mediating the Cytoprotection Of Dental Pulp Cells Against Hydrogen Peroxide

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of pH effects on genomic integrity in adipose-derived mesenchymal stem cells using the comet assay

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Assessment of the cytotoxic, genotoxic, and mutagenic potential of Acrocomia aculeata in rats

Acrocomia aculeata (Jacq.) Lodd. ex Mart. is a plant species commonly used as a foodstuff and also for treating diseases, since it contains high concentrations of antioxidant compounds and monounsaturated fatty acids. Considering its ethnopharmacological relevance, the aim of the present study was to assess the cytotoxic, genotoxic, and mutagenic effects of an oil extracted from the pulp of A. aculeata (OPAC) in rats. In addition, a chromatographic characterization of the fatty acids present in OPAC was performed. Male and female Wistar rats were treated orally with 125, 250, 500, 1000, or 2000 mg/kg/body weight OPAC. The effects of OPAC ingestion were determined by performing the comet assay and micronucleus test. The comet assay data demonstrated that OPAC did not increase the frequency or rate of DNA damage in groups treated with any of the concentrations assessed compared to that in the negative control group. In the micronucleus test, the animals treated did not exhibit any cytotoxic or mutagenic changes in peripheral blood erythrocytes. The results demonstrated that OPAC did not exhibit cytotoxic, genotoxic, or mutagenic effects in Wistar rats, thereby increasing the evidence for the safety of oil extracted from this plant.

C-2, N-dimethylbenzylamine cyclopalladated compounds: evaluation of cytotoxic, mutagenic and antitubercular activities

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