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Assessment of Quercetin Isolated from Enicostemma Littorale Against Few Cancer Targets: An in Silico Approach
Published in A. K. Haghi, Ana Cristina Faria Ribeiro, Lionello Pogliani, Devrim Balköse, Francisco Torrens, Omari V. Mukbaniani, Applied Chemistry and Chemical Engineering, 2017
Thus, on the whole, among the ten proteins that were targeted, the level of interactions had been very excellent for the phyto-ligand (quercetin). In fact, the kind of interaction observed could be categorized into two: one which is showing more number of interactions by more or less the same residues (compared with synthetic and phto-ligand) as well with other important residues, thereby increasing the G. score by two fold or three fold; and the other could be attributable to the kind of residues (denotes the properties of the amino acid) showing additional interaction for instance O—O (e.g., In DHFR, VAL at 115th position also interacted by O-O in addition to O-H) or exhibited replaced interaction. In AR, THR at 877th position was exchanged by H-O instead of O-O which either effected or affected the docking energy G. score. For instance, the interaction between Bcl-2 protein and quercetin was observed with significant interactions (9 bonding) and best G. score (-5.74 Kcal/mol) followed by quercetin with EGF showing six number of interactions with docking energy of -5.21 Kcal/mol. However, the complex quercetin with RAF protein showed greater G. score of -7.82 Kcal/mol could still not be considered favorable as the hydrogen bond exhibits 3.0 Å inter atomic forces extended by this and perhaps with only few residues when compared to Bcl-2 interaction with phyto-ligand. Even though the interaction between folinic acid and TS showed 6 numbers of interactions with highest G. score about -10.85 Kcal/mol than quercetin still could not considered favorably as it violated the ADME-Tox properties, therefore even on the basis of toxicity prediction and binding affinity observation the Bcl-2 protein interaction with quercetin was found significant and further taken to the dynamics analysis.
Toxicology
Published in Samuel C. Morris, Cancer Risk Assessment, 2020
The acceptance of animal models by the risk assessment community is exemplified by a set of principles (Table 8-2) established for EPA by the National Research Council Committee on Drinking Water and Health (NAS, 1977; 1986). The last principle is of especial interest here, since it advocates quantitative risk assessment, rather than qualitative determination of a “safe” or “not safe” level. EPA’s Gene-Tox Carcinogen Data Base provides a means to evaluate the ability of various bioassays to predict carcinogenicity of chemicals (Nesnow et al., 1986).
Recombinant Antigens as Components of a Diphtheria-Tetanys-PerSüssis Vaccine
Published in Yoshikatsu Murooka, Tadayuki Imanaka, Recombinant Microbes for Industrial and Agricultural Applications, 2020
Andrew J. Makoff, Ian G. Charles, Neil F. Fairweather
Diphtheria is an infectious disease caused by local invasion of the nasopharyngeal tissues by a strain of Corynebacterium diphtheriae that secretes the lethal diphtheria toxin. The infection results in a hemorrhagic, necrotic lesion overlaid by a tough, fibrinous membrane caused by the growth of the organism. In toxigenic strains of C. diphtheriae, the toxin is expressed from the tox gene located on a bacteriophage [reviewed in Ref. 4].
Genotoxic effects of caffeine in female mice exposed during pregnancy and lactation period and their offspring
Published in Journal of Environmental Science and Health, Part C, 2023
Marina Lummertz Magenis, Pamela Souza de Marcos, Adriani Paganini Damiani, Anderson Ricardo Cantareli da Silva, Luiza Martins Longaretti, Ive Bahia Franca, Juliana Da Silva, Carina Rodrigues Boeck, Vanessa Moraes de Andrade
The MN test was performed according to the guidelines of the Gene-Tox program of the U.S. Environmental Protection Agency.49,50 Bone marrow was extracted from the femurs of the animals. Smears were prepared directly on microscopic slides with drops of fetal calf serum. The slides were subjected to Giemsa staining (5%), air-dried, and coded for blind analysis. To avoid false-negative results and as a measure of toxicity in the bone marrow, the ratio of polychromatic erythrocytes to normochromatic erythrocytes (PCE/NCE) was scored. The incidence of MN was observed in 2000 polychromatic erythrocytes (acute exposure) and 2000 normochromatic erythrocytes (chronic exposure) per animal (two slides from each animal) using bright-field optical microscopy (1000X magnification with immersion oil). The mean values of micronucleated polychromatic erythrocytes (MNPCE) and micronucleated normochromatic erythrocytes (MNNCE) were used as the experimental units, with variability (standard deviation) based on the differences among animals within the same groups.
Assessing how in vitro assay types predict in vivo toxicology data
Published in Journal of Toxicology and Environmental Health, Part A, 2021
Adrienne Phifer, George Gray, Jessica Kratchman, Matias S. Attene-Ramos
In vitro HTS assays assessed in this study were generated by Tox21 and downloaded from the NIH NCATS website (available at: Tox21 Data (nih.gov)) (National Institutes of Health 2020) (Table 2). In vitro HTS assays with channel outcomes of inconclusive or active, as designated by Tox21, were retained and used to model concentration-response curves (Huang 2016; Huang et al. 2018, 2016). For in vitro HTS assays that did not designate a channel outcome, activity was assessed based upon curve class, as described in the Methods. 8 in vitro HTS stress response assays and 14 in vitro HTS cytotoxicity assays were leveraged in this investigation (Table 2). Cell viability counter screen assays were categorized as cytotoxicity assays for these analyses. 1 gene tox assay was also included in stress response analyses due to its stress response toxicity pathway,while its P53 viability counter screen assay was included as a cytotoxicity assay as presented in Table 2. Twenty-four in vitro HTS cytotoxicity assays were not included in the analyses due to a lack of multiple runs at each time point tested.
Anti-hyperlipidemic effects of Campomanesia xanthocarpa aqueous extract and its modulation on oxidative stress and genomic instability in Wistar rats
Published in Journal of Toxicology and Environmental Health, Part A, 2019
Joubert Aires De Sousa, Jayne Torres De Sousa, Fernanda Brião Menezes Boaretto, Jeferson De Oliveira Salvi, Jean Fachini, Juliana Bondan Da Silva, Julia Pereira Unfer, Mariangela C Allgayer, Maria Luísa Brodt Lemes, Norma Possa Marroni, Alexandre De Barros Falcão Ferraz, Jaqueline Nascimento Picada
After euthanasia, both femurs were collected from each rat to perform the micronucleus (MN) test according to the US Environmental Protection Agency Gene-Tox Program guidelines (Mavournin et al. 1990). A group with three animals treated with a single dose of cyclophosphamide 50 mg/kg i.p. injection was included as a positive control. Bone marrow samples were suspended in fetal calf serum and smeared on clean glass slides in duplicate. Slides were air-dried, fixed in methanol, stained with 10% Giemsa and coded for blind analyses. To avoid false-negative results and to obtain a value of bone marrow toxicity, the polychromatic erythrocyte/normochromatic erythrocyte (PCE/NCE) ratio was determined in 1,000 cells. The incidence of micronuclei was observed in 2,000 PCE for each animal using bright-field optical microscopy at 1000× magnification.