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Cytotoxicity Test (cytotoxicity + test)
Selected AbstractsIn,vitro Effects of Plasmodium falciparum Dihydrofolate Reductase Inhibitors on Normal and Cancer Cell ProliferationCHEMMEDCHEM, Issue 3 2008Tiziana Rossi Prof. Toxicological evaluations were performed on two novel Plasmodium falciparum dihydrofolate reductase inhibitors and other known antimalarial drugs. Cytotoxicity tests were performed on Vero and MCF-7 cells and apoptotic and/or proliferative markers p21 and p53 and A, B1, D1, and D2 cyclines. The results are discussed and show that this molecule can be considered an interesting new candidate for further development. [source] Biocompatibility of various root canal filling materials ex vivoINTERNATIONAL ENDODONTIC JOURNAL, Issue 8 2008R. Scotti Abstract Aim, To evaluate the biocompatibility of a resin-based endodontic filler (RealSeal) using the indirect cytotoxicity test. Methodology, Human gingival fibroblasts were cultured ex vivo. Pellets of the materials to be tested were incubated for 24, 48, and 72 h at 37 °C under sterile conditions to obtain their eluates. The fibroblasts were exposed to either diluted (50%) or undiluted eluates for 24 h. A culture medium with foetal calf serum was added to the control wells. Cell viability was estimated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide method. The data concerning cell viability were statistically analyzed using one-way anova test and Bonferroni multiple comparisons test. Results, Eluates obtained after 24 h of incubation with the resin filler did not reduce cellular viability. An increase in cellular viability, as compared with control cells, was observed in the gutta-percha group. The undiluted eluate from the polyether material was cytotoxic, causing an 82 ± 4% decrease in cellular viability. Eluates obtained after 48 h of incubation with the resin filler increased cellular viability, whereas the polyether significantly reduced viability. Gutta-percha did not cause any detectable change. After 72 h of incubation the eluate of the resin filler caused an increase in cellular viability, as did gutta-percha, whereas polyether caused a significant decrease. Conclusions, RealSeal resin filler was nontoxic in this laboratory model. Further investigations are necessary to verify its usefulness in clinical applications. [source] INDIVIDUAL AND COMBINED CYTOTOXIC EFFECTS OF THE MAJOR FOUR AFLATOXINS IN DIFFERENT IN VITRO STABILIZED SYSTEMSJOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2010CORNELIA BRAICU ABSTRACT The present study aims to investigate the cytotoxic effect of the major aflatoxins (B1, B2, G2 and G2) and also aflatoxin combination, using a simple, rapid and cheap cytotoxicity test like MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay in three in vitro models (human umbilical vein endothelial cells [HUVEC], human lung fibroblasts [HFL] and A2780 cell line) and to extrapolate the data to in vivo situation using a prediction model. A difference in cell sensitivity has been observed for B1 and B1 + B2, in the following order A2789 > HFL > HUVEC, while for B2, G1, G2, Mix (B1 + B2 + G1 + G2) the order was HFL > A2789 > HUVEC when comparing the IC50 (half maximal inhibitory concentration) values. We confirm that in vitro cytotoxicity test MTT assay is able to predict in vivo toxicity, at least for aflatoxins using the prediction model. The values of LD50 (lethal dose 50%) calculated from experiments are different for each cell line. This fact may indicate that some species are more resistant than other and target organs are not necessarily those predicted, because the A2780 ovarian cancer cells seem to be more sensitive to B1 than cells of endothelial or fibroblasts origin. PRACTICAL APPLICATIONS This study is in concordance with the international tendency that refined the current techniques to lessen pain or distress, to reduce the number of animals necessary for a particular test or to replace animals with non-whole-animal models, such as in vitro cell cultures. The practical application of such methodologies may help solve the economic problem related to very expensive in vivo toxicology studies and implement preventive methods based on the calculated data and known mechanism of action of individual or combined toxins easily studied in vitro. The nature of coexistence of many types of mycotoxins in complex environmental samples, such as food and water, has been reported worldwide. How these mycotoxins might affect human health in combination is largely unknown. This study had, as a goal, to test the toxicity of the four aflatoxins and aflatoxin combination on human cells. Due to the lack of aflatoxins mixture data regarding the human cytotoxicity, the aim of this study was to specify, evaluate and predict the combined effects of mycotoxin mixtures. [source] In vitro and in vivo evaluation of a biodegradable chitosan,PLA composite peripheral nerve guide conduit materialMICROSURGERY, Issue 6 2008Feng Xie M.D., Ph.D. Chitosan, a nature biodegradable material, has good biocompatibility but poor physical properties to serve as a nerve conduit. In this study, polylactic acid (PLA) was added to chitosan to form a composite material with improved intensity and elasticity, to be used as nerve conduits. The chitosan,PLA nerve conduits were fabricated with a mold casting/infrared dehydration technique. The constituent ratio of PLA and chitosan of 1:5 (v:v) was chosen to give the composite material both good mechanical properties and good biocompatibility. An in vitro cytotoxicity test showed that the chitosan,PLA material was not cytotoxic. The conduits were proved biodegradable and had many micropores to allow permeability. We evaluated chitosan,PLA nerve conduits as a guidance channel to repair 10 mm gaps in rat sciatic nerves. Nerve autograft and silicon conduits were used as the control. After 12 weeks, the regenerating nerves in three groups succeeded in passing through the nerve gap and reinnervating the muscle. Assessments, including ECG, histomorphometric evaluation, and weighing of triceps calf muscle, showed that the functional recovery of sciatic nerve was better in chitosan,PLA conduit group than in the silicon conduit group (P < 0.05), but the differences between the chitosan,PLA conduit group and the nerve autograft group were not significant (P > 0.05). Therefore, the chitosan,PLA guide proved to be a promising nerve conduit. © 2008 Wiley-Liss, Inc. Microsurgery, 2008. [source] Synthesis, characterization, in vitro degradation and cytotoxicity of polyphosphazenes containing N -ethoxypyrrolidone side groupsPOLYMER INTERNATIONAL, Issue 2 2010Yunmei Bi Abstract A new biodegradable polyphosphazene (PYRMP) containing N -ethoxypyrrolidone and methoxyethoxyethoxy side groups was synthesized via a route of macromolecular substitution. The synthetic method of poly{bis[2-(2-oxo-1-pyrrolidinyl)ethoxy]phosphazene} (PYRP) was improved. The thermal properties of the polymers were investigated using differential scanning calorimetry. Degradation studies were carried out in vitro with varying pH conditions. The in vitro cytotoxicity of PYRMP and its hydrolysis products was evaluated using the methyl tetrazolium (MTT) cytotoxicity test in HepG2 cell culture. PYRMP and PYRP have low glass transition temperatures of ,68.8 and ,59.6 °C, respectively. The polymers show a higher degradation rate at pH = 5.0 than at both pH = 7.4 and 8.0. The degradation process of PYRMP in different buffer solutions is discussed. The MTT test reveals that PYRMP at concentrations below 800 µg mL,1 and its hydrolysis products are non-toxic to HepG2 cells. Moreover, the hydrolysis products diluted 10 times are able to promote cell proliferation. This study shows that polyphosphazene containing N -ethoxypyrrolidone subsituents provides interesting perspectives for various biomedical applications. Copyright © 2009 Society of Chemical Industry [source] Influence of 1 and 25 Hz, 1.5 mT magnetic fields on antitumor drug potency in a human adenocarcinoma cell line,BIOELECTROMAGNETICS, Issue 8 2002M.J. Ruiz-Gómez Abstract The resistance of tumor cells to antineoplastic agents is a major obstacle during cancer chemotherapy. Many authors have observed that some exposure protocols to pulsed electromagnetic fields (PEMF) can alter the efficacy of anticancer drugs; nevertheless, the observations are not clear. We have evaluated whether a group of PEMF pulses (1.5 mT peak, repeated at 1 and 25 Hz) produces alterations of drug potency on a multidrug resistant human colon adenocarcinoma (HCA) cell line, HCA-2/1cch. The experiments were performed including (a) exposures to drug and PEMF exposure for 1 h at the same time, (b) drug exposure for 1 h, and then exposure to PEMF for the next 2 days (2 h/day). Drugs used were vincristine (VCR), mitomycin C (MMC), and cisplatin. Cell viability was measured by the neutral red stain cytotoxicity test. The results obtained were: (a) The 1 Hz PEMF increased VCR cytotoxicity (P,<,0.01), exhibiting 6.1% of survival at 47.5 ,g/ml, the highest dose for which sham exposed groups showed a 19.8% of survival. For MMC at 47.5 ,g/ml, the % of survival changed significantly from 19.2% in sham exposed groups to 5.3% using 25 Hz (P,<,0.001). Cisplatin showed a significant reduction in the % of survival (44.2,39.1%, P,<,0.05) at 25 Hz and 47.5 ,g/ml, and (b) Minor significant alterations were observed after nonsimultaneous exposure of cells to PEMF and drug. The data indicate that PEMF can induce modulation of cytostatic agents in HCA-2/1cch, with an increased effect when PEMF was applied at the same time as the drug. The type of drug, dose, frequency, and duration of PEMF exposure could influence this modulation. Bioelectromagnetics 23:578,585, 2002. © 2002 Wiley-Liss, Inc. [source] Anthracene photoinduced toxicity to plhc-1 cell line (Poeciliopsis lucida) and the role of lipid peroxidation in toxicityENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2000Jonghoon Choi Abstract Many polycyclic aromatic hydrocarbons (PAHs) are acutely toxic to fish and other aquatic organisms in the presence of solar ultraviolet radiation (SUVR) of environmentally realistic intensities. In the present study, the photoinduced toxicity of a PAH (anthracene; ANT) to topminnow hepatoma cell line (PLHC-1) was assessed. After the toxicity was characterized, the role of lipid peroxidation in PAH photoinduced toxicity was examined by measuring lipid peroxidation products and by assessing the effect of lipid peroxidation antagonist (Trolox) treatment. In cytotoxicity tests using two assays (MTT, neutral red), the SUVR/ANT treatment elicited toxicity to PLHC-1 cells in a concentration- and SUVR (exposure duration and intensity)-dependent pattern. As found in previous organism-level studies, no significant cytotoxicity was observed in the cells exposed either to fluorescent light/ANT or to SUVR only. The SUVR/ANT treatment elicited the lipid peroxidation process and Trolox pretreatment significantly reduced SUVR/ANT-induced cell mortality. Microscopic observation showed that Trolox pretreatment relieved the SUVR/ANT-inflicted damage, such as cell shrinkage and membrane disruption. Together with a recent finding in our lab that increased production of superoxide anion and a lipid peroxidation product (malondialdehyde) was found in SUVR/ANT-treated fish microsomes, the present study suggests that reactive oxygen radical-induced lipid peroxidation is an important factor in PAH photoinduced toxicity to fish. [source] Phytochemistry and preliminary biological evaluation of Cyathostemma argenteum, a malaysian plant used traditionally for the treatment of breast cancerPHYTOTHERAPY RESEARCH, Issue 7 2004i Khamis Abstract Bioassay guided fractionation of the roots of Cyathostemma argenteum using the brine shrimp resulted in the isolation of two uncommon ,avanones, 2,5-dihydroxy-7-methoxy,avanone 1 and 2,5-dihydroxy-6,7-dimethoxy,avanone 2 while the stem bark yielded the related compounds 5-hydroxy-7-methoxy,avone 3 and 5-hydroxy-6,7-dimethoxy,avone 4. The alkaloids liriodenine 5 and discretamine 6 as well as benzyl benzoate 7 were isolated from the roots and 6 was also isolated from the stembark. In cytotoxicity tests using four human breast cancer cell lines, 1 and 2 were weakly toxic to MCF-7 cells (IC50 = 19.6 and 19.0 µm, respectively) but showed little activity against MCF-7 cells resistant to doxorubicin or against two oestrogen receptor-de,cient cell lines. Compound 5, but not 6 and 7, was moderately cytotoxic against all four cell lines. These results are discussed in the context of the traditional use of C. argenteum in the treatment of breast cancer. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||||||||