Root canal dressings for revascularization influence in vitro mineralization of apical papilla cells

Abstract Endodontic revascularization is based on cell recruitment into the necrotic root canal of immature teeth after chemical disinfection. The clinical outcome depends on the ability of surviving cells from the apical tissue to differentiate and promote hard tissue deposition inside the dentinal walls. Objective To investigate the effect of calcium hydroxide (CH) and modified triple antibiotic paste (mTAP - ciprofloxacin, metronidazole and cefaclor) on the viability and mineralization potential of apical papilla cells (APC) in vitro . Material and Methods APC cultures were kept in contact with CH or mTAP (250-1000 µg/mL) for 5 days, after which cell viability was assessed using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Next, APCs were subjected to CH or mTAP at 250 µg/mL for 5 days before inducing the differentiation assay. After 14 and 21 days, calcium deposition was assessed by the Alizarin Red S staining method, followed by elution and quantification using spectrophotometry. Data were analyzed using ANOVA followed by Tukey post hoc test. Results CH induced cell proliferation, whereas mTAP showed significant cytotoxicity at all concentrations tested. APC treated with CH demonstrated improved mineralization capacity at 14 days, while, for mTAP, significant reduction on the mineralization rate was observed for both experimental periods (14 and 21 days). Conclusion Our findings showed that CH induces cell proliferation and improves early mineralization, whereas mTAP was found cytotoxic and reduced the mineralization potential in vitro of APCs.

Inhibitory effects of jiajianzhujing decoction containing serum on proliferation of rat choroidal vascular endothelial cells / 中华实验眼科杂志

Background Choroidal neovascularization (CNV) of macular zone is one of blinding eye diseases.Conventional treatment methods include photodynamic therapy and intravitreal injection of anti-vascular endothelial growth factor (VEGF) drugs.However,there are some adverse effects following these treatments.Researches showed that fiajianzhujing decoction,a Chinese herbal medicine,can inhibit CNV.Objective This study was to investigate the impact of drug serum offiajianzhujing decocation (drug serum) on the proliferation of rat choroidal vascular endothelial cells (RCVECs).Methods Jiajianzhujing decoction (0.525 g/ml) was used by intragastric administration with the dosage 20 ml/kg for 3 days,and the abdominal aortic blood was collected 2 hours after last dosage to prepare the drug serum.Cultured RCVECs were divided into 4 groups.CoCl2 with the concentration of 100 μmol/L (100 μl) was added in the medium to establish the anoxic models in the CoCl2 group,and 20％ drug serum was added in the anoxic culture medium in the drug serum+CoCl2 group.Regular culture medium was used in the blank control group,and 20％ pure serum was added in the anoxic culture medium in the pure serum+CoCl2 group.The cells were incubated for consecutive 24 hours,and the growth of the cells was detected by monotetrazolium (MTT) assay as absorbance (A).The expressions of gene and protein of hypoxia-inducible factor-1 α (HIF-1 α) and VEGF in the cells were detected by reverse transcription PCR and Western blot,respectively.This study was approved by the Ethics Committee of Eye Hospital of China Academy of Chinese Medical Sciences.Results Cultured cells grew well with fusiform shape.Hypoxic cell models were created by adding CoCl2.The mean A values were 0.659± 0.051,0.757±0.553,0.683±0.037 and O.731 ±O.038 in the blank control group,CoCl2 group,drug serum+CoCl2 group and pure serum+CoCl2 group,respectively,and the A value in the CoCl2 group was significantly elevated in comparison with the blank control group and drug serum+CoCl2 group (both at P＜0.O1).The significant differences were found in the relative expressions of HIF-1 α and VEGF among the blank control group,CoCl2 group,drug serum+ CoC12 group and pure serum+CoCl2 group (HIF-1 α:F =3.100,P＜0.05;VEGF mRNA:F =3.420,P＜0.05;HIF-1 α protein:F=470.600,P =0.000;VEGF protein:F =146.700,P =0.000),and the relative expressions of HIF-1α mRNA,VEGF mRNA,HIF-1α protein and VEGF protein in the CoCl2 group were significantly higher than those in the blank control group and drug serum+CoCl2 group (all at P＜0.05).Conclusions Drug serum ofjiajianzhujing decoction can inhibit the growth and proliferation of hypoxic RCVECs by down-regulating the secretion of HIF-1α and VEGF.

A new polyphenol, 1, 3-di-O-caffeoyl-5-O-(1-methoxyl-2-O-caffeoyl-4-maloyl)-quinic acid, isolated from cultured cells of Saussurea involucrata / 中国天然药物

The present study was designed to isolate the polyphenol constituents of cultured cells of Saussurea involucrata. The polyphenol type constituents were isolated using chromatography methods, and then characterized by spectral analysis. 1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)-hydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) free radical scavenging were assayed using Vitamin C as the positive control. One new polyphenol 18, 1, 3-di-O-caffeoyl-5-O-(1-methoxyl-2-O-caffeoyl-4-maloyl)-quinic acid, together with 17 known compounds, was isolated and characterized. In conclusion, Compound 18 was a new caffeoyl maloyl quinic acid type polyphenol and showed desired vitro anti-oxidant activity. Compounds 1-5, 9, 10, 14, 15, and 17 were isolated from cultured cells of Saussurea involucrata for the first time.

Peroxide effects of iodide excess on mitochondria in Fischer rat thyroid cell line in the early period / 中华地方病学杂志

Objective To investigate the peroxide effects of iodide excess on mitochondria in Fischer rat thyroid cell line(FRTL) in the early period.Methods After treatment with 0.0 mmol/L(control group) or 0.1 mmol/L potassium iodide(KI) for 2,4 and 24 h,respectively,changes of mitochondrial superoxide formation were assayed by flow cytometry and fluorescence microscopy using mitochondria-targeted hydroethidine(MitoSOX).The cytochrome c (cyt c) released from mitochondria to cytoplasm was detected by immunocytochemistry.The lactate dehydrogenase (LDH) released into supernatant was measured by a LDH kit using colorimetry.The percent of dead cells was assayed by flow cytometry using propidium iodide (PI).DNA with loading buffer was separated in 1％ agarose gel.Results Mitochondrial superoxide production in FRTL cells treated with 0.1 mmol/L KI was increased at 2; 4 and 24 h,especially at 2 h.The rates of cyc c protein immunity positive cells at 2,4 and 24 h in 0.1 mmol/L KI group were (35.3 ± 3.6)％,(45.8 ± 5.5)％ and (30.3 ± 6.1)％,respectively,which were significantly higher than that in control group[(14.8 ± 1.2)％,all P ＜ 0.05].The LDHs released into supernatant at 2,4 and 24 h in 0.1 mmol/L KI group were (1.85 ± 0.32),(6.63 ± 0.42) and (8.35 ± 0.34)U/mg,and these values at 4 and 24 h in 0.1 mmol/L KI group were significantly higher than that of control group[(0.89 ± 0.04)U/mg,all P ＜ 0.05].After incubation with 0.1 mmol/L KI for 2,4 and 24 h,the percentages of dead FRTL cells were 7.52％,9.29％ and 13.71％,respectively,while that of control group was 4.66％.After FRTL cells were treated with 0.1 mmol/L KI for 24 h,DNA ladder appeared.Conclusion Iodide excess (0.1 mmol/L) can cause mitochondrial peroxide injury in FRTL cells at 2 h and cell apoptosis at 24 h.

Long-term cytotoxic effects of contemporary root canal sealers

Objectives: The aim of the present study was to investigate the effects of root canal sealers on the cytotoxicity of 3T3 fibroblasts during a period of 5 weeks. Material and Methods: Fibroblasts (3T3, 1×105 cells per well) were incubated with elutes of fresh specimens from eight root canal sealers (AH Plus, Epiphany, Endomethasone N, EndoREZ, MTA Fillapex, Pulp Canal Sealer EWT, RoekoSeal and Sealapex) and with elutes of the same specimens for 5 succeeding weeks after immersing in simulated body fluid. The cytotoxicity of all root canal sealers was determined using the MTT assay. Data were analyzed using ANOVA and Tukey's test. Results: RoekoSeal was the only sealer that did not show any cytotoxic effects (p<0.05). All the other tested sealers exhibited severe toxicity initially (week 0). MTA Fillapex remained moderately cytotoxic after the end of experimental period. Toxicity of the other tested sealers decreased gradually over time. The evaluated root canal sealers presented varying degrees of cytotoxicity, mainly in fresh mode.Conclusions: RoekoSeal had no cytotoxic effect both freshly mixed and in the other tested time points. MTA Fillapex was associated with significantly less cell viability when compared to the other tested root canal sealers.

Cholesterol Depletion in Cell Membranes of Human Airway Epithelial Cells Suppresses MUC5AC Gene Expression

PURPOSE: If cholesterol in the cell membrane is depleted by treating cells with methyl-beta-cyclodextrin (MbetaCD), the activities of transmembrane receptors are altered in a cell-specific and/or receptor-specific manner. The proinflammatory cytokines, IL-1beta is potent inducers of MUC5AC mRNA and protein synthesis in human airway epithelial cells. Cells activated by IL-1beta showed increased phosphorylation of extracellular signal regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK). Thus, we investigated the effects of cholesterol depletion on the expression of MUC5AC in human airway epithelial cells and whether these alterations to MUC5AC expression were related to MAPK activity. MATERIALS AND METHODS: After NCI-H292 cells were pretreated with 1% MbetaCD before adding IL-1beta for 24 hours, MUC5AC mRNA expression was determined by reverse transcription-polymerase chain reaction (RT-PCR) and real time-PCR. Cholesterol depletion by MbetaCD was measured by modified microenzymatic fluorescence assay and filipin staining. The phosphorylation of IL-1 receptor, ERK and p38 MAPK, was analyzed by western blot. RESULTS: Cholesterol in the cell membrane was significantly depleted by treatment with MbetaCD on cells. IL-1beta-induced MUC5AC mRNA expression was decreased by MbetaCD and this decrease occurred IL-1-receptor-specifically. Moreover, we have shown that MbetaCD suppressed the activation of ERK1/2 and p38 MAPK in cells activated with IL-1beta. This result suggests that MbetaCD-mediated suppression of IL-1beta-induced MUC5AC mRNA operated via the ERK- and p38 MAPK-dependent pathway. CONCLUSION: Cholesterol depletion in NCI-H292 cell membrane may be considered an anti-hypersecretory method since it effectively inhibits mucus secretion of respiratory epithelial cells.

Evaluation of tissue reaction, cell viability and cytokine production induced by Sealapex Plus

OBJECTIVE: The aim of this study was to investigate the effects of mineral trioxide aggregate (MTA), Sealapex, and a combination of Sealapex and MTA (Sealapex Plus) on the reaction of subcutaneous connective tissue of rats, and on cell viability and cytokine production in mouse fibroblasts. MATERIAL AND METHODS: The tissue reaction was carried out with dentin tubes containing the materials implanted in the dorsal connective tissue of rats. The histological analysis was performed after 7 and 30 days. Millipore culture plate inserts with polyethylene tubes filled with materials were placed into 24-well cell culture plates with mouse fibroblasts to evaluate the cell viability by MTT assay. ELISA assays were also performed after 24 h of exposure of the mouse fibroblasts to set material disks. RESULTS: Histopathologic examination showed Von Kossa-positive granules that were birefringent to polarized light for all the studied materials at the tube openings. No material inhibited the cell viability in the in vitro test. It was detected IL-6 production in all root-end filling materials. MTA and Sealapex Plus induced a slight raise of mean levels of IL-1β. CONCLUSIONS: The results suggest that Sealapex Plus is biocompatible and stimulates the mineralization of the tissue.

Estudo comparativo da citotoxicidade de cimentos obturadores sobre culturas de células endoteliais da linhagem ECV 304 / Comparative study of cytotoxicity of sealers on cultured endothelial cells line ECV 304

Este estudo teve como objetivo avaliar, in vitro, a citotoxicidade dos cimentos endodônticos Densell Endo®, Pulp-Fill®, Endofill®, Sealer 26®, Pulp Canal Sealer® e GuttaFlow® após 12, 24 e 72 horas de tempo de contato, utilizando-se uma linhagem de células endoteliais ECV-304. Para a avaliação da viabilidade celular, utilizou-se o teste de citotoxicidade MTT. Para cada cimento foram preparados 12 corpos de prova que foram distribuídos em seis grupos experimentais de acordo com as marcas comerciais, sendo quatro para cada tempo. Foi criado um grupo controle que não foi submetido à ação de cimento. Para avaliação do efeito dos cimentos sobre as células endoteliais, os corpos de prova foram inseridos nos poços da placa cultura, incubados a 37ºC em presença de 5% de CO2 e 100% de umidade. Os testes MTT foram realizados, em quadruplicata, após 12, 24 e 72 horas de contato das amostras com o tapete celular. Foi utilizada a prova Two-Way Anova com o teste Post Hoc de Bonferroni com nível de significância de 5%. Na análise de 12 horas, foi possível observar que o cimento GuttaFlow® apresentou média de absorbância de 0,055, seguido do Sealer 26® (média = 0,038). Os cimentos Pulp Canal Sealer® e Densell Endo® apresentaram a mesma média de absorbância (0,031). O Pulp Fill® e o Endofill® foram os cimentos que apresentaram maior citotoxicidade (média de absorbância = 0,024 e 0,021, respectivamente). O grupo controle apresentou média de absorbância de 0,158. Em 24 horas observou-se que os cimentos GuttaFlow® e Sealer 26® apresentaram as maiores médias de absorbância (0,041 e 0,037, respectivamente), seguidos pelo cimento Pulp Canal Sealer® que apresentou média de absorbância de 0,035. Já os cimentos Densell Endo® e Pulp Fill® apresentaram médias de absorbância de 0,033 e 0,032, respectivamente. O cimento Endofill® apresentou uma média de 0,026 e o grupo controle de 0,086. Quando analisados em 72 horas, o cimento Pulp Canal Sealer® obteve média de absorbância...

This study aimed to evaluate, in vitro, cytotoxicity of root canal sealers Densell Endo®, Pulp-Fill®, Endofill®, Sealer 26®, Pulp Canal Sealer® and GuttaFlow® after 12, 24 and 72 hours of contact time, using a endothelial cell line ECV-304. For the assessment of cell viability, used the MTT cytotoxicity test. For any cement were prepared 12 specimens that were divided into six groups according to the trademarks, four for each time. Created a control group that was not subjected to action of cement. To assess the effects of cements on endothelial cells, the specimens were placed in culture plate wells, incubated at 37°C with 5% CO2 and 100% humidity. MTT tests were performed, in quadruplicate, after 12, 24 and 72 contact hours of the samples with monolayers. Was used to test Two-Way Anova with Bonferroni Post Hoc test with significance level of 5%. In the analysis of 12 hours, was observed that the cement GuttaFlow® had a mean absorbance of 0,055, followed by Sealer 26® (average = 0,038). Cements Pulp Canal Sealer® and Densell Endo® had the same mean absorbance (0,031). The Pulp Fill® and Enfofill® were the cements with higher cytotoxicity (mean absorbance = 0,024 and 0,021, respectively). The control group had a mean absorbance of 0,158. In 24 hours it was observed that the cements Sealer 26® and GuttaFlow® had the highest average absorbance (0,041 and 0,037, respectively), followed by cement Pulp Canal Sealer® that had a mean absorbance of 0.035. Already cements Densell Endo® and Pulp Fill® showed means absorbance of 0,033 and 0,032, respectively. Cement Endofill showed an average of 0,026 and the control group, 0,086. When analyzed at 72 hours, the cement Pulp Canal Sealer® had an average absorbance of 0,049, followed by cement GuttaFlow® and Pulp Fill®, both with 0,048. Cements Densell Endo®, Sealer 26® and Endofill® showed respectively, averaging 0,044, 0,040 and 0,036. The control group differed significantly...

Estudo comparativo da citotoxicidade de cimentos obturadores sobre culturas de células endoteliais da linhagem ECV 304 / Comparative study of cytotoxicity of sealers on cultured endothelial cells line ECV 304

Este estudo teve como objetivo avaliar, in vitro, a citotoxicidade dos cimentos endodônticos Densell Endo®, Pulp-Fill®, Endofill®, Sealer 26®, Pulp Canal Sealer® e GuttaFlow® após 12, 24 e 72 horas de tempo de contato, utilizando-se uma linhagem de células endoteliais ECV-304. Para a avaliação da viabilidade celular, utilizou-se o teste de citotoxicidade MTT. Para cada cimento foram preparados 12 corpos de prova que foram distribuídos em seis grupos experimentais de acordo com as marcas comerciais, sendo quatro para cada tempo. Foi criado um grupo controle que não foi submetido à ação de cimento. Para avaliação do efeito dos cimentos sobre as células endoteliais, os corpos de prova foram inseridos nos poços da placa cultura, incubados a 37ºC em presença de 5% de CO2 e 100% de umidade. Os testes MTT foram realizados, em quadruplicata, após 12, 24 e 72 horas de contato das amostras com o tapete celular. Foi utilizada a prova Two-Way Anova com o teste Post Hoc de Bonferroni com nível de significância de 5%. Na análise de 12 horas, foi possível observar que o cimento GuttaFlow® apresentou média de absorbância de 0,055, seguido do Sealer 26® (média = 0,038). Os cimentos Pulp Canal Sealer® e Densell Endo® apresentaram a mesma média de absorbância (0,031). O Pulp Fill® e o Endofill® foram os cimentos que apresentaram maior citotoxicidade (média de absorbância = 0,024 e 0,021, respectivamente). O grupo controle apresentou média de absorbância de 0,158. Em 24 horas observou-se que os cimentos GuttaFlow® e Sealer 26® apresentaram as maiores médias de absorbância (0,041 e 0,037, respectivamente), seguidos pelo cimento Pulp Canal Sealer® que apresentou média de absorbância de 0,035. Já os cimentos Densell Endo® e Pulp Fill® apresentaram médias de absorbância de 0,033 e 0,032, respectivamente. O cimento Endofill® apresentou uma média de 0,026 e o grupo controle de 0,086. Quando analisados em 72 horas, o cimento Pulp Canal Sealer® obteve média de absorbância ...

This study aimed to evaluate, in vitro, cytotoxicity of root canal sealers Densell Endo®, Pulp-Fill®, Endofill®, Sealer 26®, Pulp Canal Sealer® and GuttaFlow® after 12, 24 and 72 hours of contact time, using a endothelial cell line ECV-304. For the assessment of cell viability, used the MTT cytotoxicity test. For any cement were prepared 12 specimens that were divided into six groups according to the trademarks, four for each time. Created a control group that was not subjected to action of cement. To assess the effects of cements on endothelial cells, the specimens were placed in culture plate wells, incubated at 37°C with 5% CO2 and 100% humidity. MTT tests were performed, in quadruplicate, after 12, 24 and 72 contact hours of the samples with monolayers. Was used to test Two-Way Anova with Bonferroni Post Hoc test with significance level of 5%. In the analysis of 12 hours, was observed that the cement GuttaFlow® had a mean absorbance of 0,055, followed by Sealer 26® (average = 0,038). Cements Pulp Canal Sealer® and Densell Endo® had the same mean absorbance (0,031). The Pulp Fill® and Enfofill® were the cements with higher cytotoxicity (mean absorbance = 0,024 and 0,021, respectively). The control group had a mean absorbance of 0,158. In 24 hours it was observed that the cements Sealer 26® and GuttaFlow® had the highest average absorbance (0,041 and 0,037, respectively), followed by cement Pulp Canal Sealer® that had a mean absorbance of 0.035. Already cements Densell Endo® and Pulp Fill® showed means absorbance of 0,033 and 0,032, respectively. Cement Endofill showed an average of 0,026 and the control group, 0,086. When analyzed at 72 hours, the cement Pulp Canal Sealer® had an average absorbance of 0,049, followed by cement GuttaFlow® and Pulp Fill®, both with 0,048. Cements Densell Endo®, Sealer 26® and Endofill® showed respectively, averaging 0,044, 0,040 and 0,036. The control group differed significantly ...(AU)

Effects of light-curing time on the cytotoxicity of a restorative composite resin on odontoblast-like cells

This in vitro study evaluated the cytotoxicity of an experimental restorative composite resin subjected to different light-curing regimens. METHODS: Forty round-shaped specimens were prepared and randomly assigned to four experimental groups (n=10), as follows: in Group 1, no light-curing; in Groups 2, 3 and 4, the composite resin specimens were light-cured for 20, 40 or 60 s, respectively. In Group 5, filter paper discs soaked in 5 µL PBS were used as negative controls. The resin specimens and paper discs were placed in wells of 24-well plates in which the odontoblast-like cells MDPC-23 (30,000 cells/cm²) were plated and incubated in a humidified incubator with 5 percent CO2 and 95 percent air at 37ºC for 72 h. The cytotoxicity was evaluated by the cell metabolism (MTT assay) and cell morphology (SEM). The data were analyzed statistically by Kruskal-Wallis and Mann-Whitney tests (p<0.05). RESULTS: In G1, cell metabolism decreased by 86.2 percent, indicating a severe cytotoxicity of the non-light-cured composite resin. On the other hand, cell metabolism decreased by only 13.3 percent and 13.5 percent in G2 and G3, respectively. No cytotoxic effects were observed in G4 and G5. In G1, only a few round-shaped cells with short processes on their cytoplasmic membrane were observed. In the other experimental groups as well as in control group, a number of spindle-shaped cells with long cytoplasmic processes were found. CONCLUSION: Regardless of the photoactivation time used in the present investigation, the experimental composite resin presented mild to no toxic effects to the odontoblast-like MDPC-23 cells. However, intense cytotoxic effects occurred when no light-curing was performed.

The influence of centrifugal speed and time on TEM sample preparation of culture cell / 重庆医科大学学报

Objective:To investigate the influences of different centrifugal conditions on the ultrastructure of cultured cells in the digestion centrifugation to find out the best speed and time of centrifugation.Methods:The cultured cells after digested,were divided into groups according to different digestion centrifuge speed and time,and the changes of cell morphology in each group at different centrifugation time and speed were compared under transmission electron microscope.Results:Enough cells could mot be collected with the centrifuge speed less than 800 r/min,8 min.The cells were deformed due to extrusion or the cytoplasm was torn with the speed of 2 000 r/min,15 min.With the speed of 800～1 500 r/min,8～15 min,it was more proper to prepare samples and preserve cell ultrastructure.Conclusion:It is ideal to prepare TEM samples of cultured cells by using the cells being digested and centrifuged with speed at 800 ~1 500 r/min and time of 8~15 minutes.

Inhibition in in vitro proliferation human prostate cancer PC_3 cells induced by melatonin / 中国药理学通报

AIM To explore the inhibition in in vitro p roliferation human prostate cancer PC 3 cells induced by melatonin and the effe ct of combination of melatonin and 5-Fu. METHODS Cell growth cu rve, MTT assay, and acid phosphatase(ACP)activity were used to determine cell proliferation. Coomassie brillient blue assay and modified diphenylamine assay w ere used to measure the content of protein and DNA in PC 3 cells. ACP activity was measured by modified phenyl phosphat e method of kind and king and modified method of lowry. Co-administration effec t of MLT and 5-fluorouracil(5-Fu)on PC 3 cell proliferation was determined by MTT assay. RESULTS The IC 50 of MLT for inhibiting PC 3, CoLo205, K562, and HeLa cell proliferation was(1 20?0 30),(1 27?0 12) ,(1 60?0 16)and(2 25?0 11)mmol?L -1 , respectively. And MLT inhib ited all above cells proliferation in a concentration-dependent manner. The protein and DNA content and ACP activity in PC 3 cell treated with 2 mmol?L -1 MLT for 96 h were redu ced 58 77%, 54 97% and 89 24%, respectively. When PC 3 cells were treated wi th MLT in combination with 5-Fu 0 5 mg?L -1 , the inhibition rate enhance d. CONCLUSION MLT inhibited PC 3, CoLo205, K562, and HeLa cell p roliferation, and reduced the content of protein and DNA and ACP activity in PC 3 cell. MLT and 5-Fu co-administration enhanced the inhibition rate of PC 3.er.TheproteinandDNAcontentandACPactivityinPC3 celltreatedwith 2mmol?L-1MLTfor 96hwerereduced5 8 77% ,5 4 97%and 89 2 4% ,respectively .WhenPC3 cellsweretreatedwithMLTincombinationwith5 Fu 0 5mg?L-1,theinhibitionrateenhanced .CONCLUSION　MLTinhibitedPC3 ,CoLo2 0 5 ,K5 62 ,

EFFECT OF QUERCETIN ON CULTURED HUMAN VASCULARENDOTHELIAL CELLS / 药物分析学报

Objective To study the effects of quercetin (Que) on the release of endothelin-1(ET-1) and prosta cylin(PGI2) by normal human vascular endothelial cell(VEC). Methods Radioimmunoassay(RIA) was used to assess the amount of ET-1 and PGI2 produced by VEC. VEC proliferation was assessed by tetrazolium(MTT) assay. Results Que increased the normal VEC proliferation at the concentration of 5, 20, 40, 80, 100μmol/L and increased the pro duction of PGI2 and inhibits the release of ET by the normal VEC at the concentration of 5, 20 and 80μmol/L. Que at the concentration of 5, 20 and 80μmol/L had no direct effect on morphology of the normal VEC. Conclusion Que can stimulate the proliferation of VEC and inhibit the release of ET-1 and increase the formation of PGI2. The data sug gest that Que might be beneficial for the prevention and treatment of vascular endothelial injury-related cardiovascu lar diseases, such as atherosclerosis and thromboembolism diseases.

Uptake of Ga-67 by Cultured Cells: Transferrin-dependent and Transferrin-independent Mechanisms / 대한암학회지

PURPOSE: We determined whether the uptake of Ga-67 by cultured cells occur by both transferrin (Tf)-dependent and independent mechanisms and the mechanism and magnitude of its uptake may vary as the degree of expression of the transformed phenotype. MATERIALS AND METHODS: Uptake of Ga-67 between the tansformed and untransformed cells was compared. Cells were incubated with Ga-67 in either the presence or absence of Tf and with complete medium containing Ga-67 after preincubating with anti-Tf receptor antibodies at 37oC in 8% CO2. Monolayers of cells were washed and trypsinized. Radioactivity and protein content of the samples were determined. RESULTS: Uptake of Ga-67 by cultured cells occurred both in Tf-bound and ionic form and was increased with radioactivity and time. The magnitude for the uptake of Tf-bound form was approximately 3 and 6-fold greater than ionic form. In the presence of Tf, uptake of Ga-67 was 2-fold greater in the transformed cells. Conversely, In the absence of Tf, it was 1.5-fold greater in the untransformed cells. Regardless of blocking the Tf receptor by anti-Tf receptor antibodies, a significant amount of intracellular Ga-67 uptake was found. CONCLUSION: Dual mechanisms exist for the uptake of Ga-67 by cultured cells. The primary important one was the Tf-dependent system. Tf-dependent and independent mechanisms and the magnitude operated oppositely in the transformed cells when compared to their untransformed counterpart.

Advances in pharmacological studies of silymarin

Silymarin is the flavonoids extracted from the seeds of Silybum marianum (L) Gearth as a mixture of three structural isomers: silybin, silydianin and silychristin, the former being the most active component. Silymarin protects liver cell membrane against hepatotoxic agents and improves liver function in experimental animals and humans. It is generally accepted that silymarin exerts a membrane-stabilizing action preventing or inhibiting membrane peroxidation. The experiments with soybean lipoxygenase showed that the three components of silymarin brought about a concentration-dependent non-competitive inhibition of the lipoxygenase. The experiments also showed an analogous interaction with animal lipoxygenase, thus showing that an inhibition of the peroxidation of the fatty acid in vivo was self-evident. Silybin almost completely suppressed the formation of PG at the highest concentration (0.3 mM) and proved to be an inhibitor of PG synthesis in vitro. In our experiments, silybin at lower dose (65 mg/Kg) decreased liver lipoperoxide content and microsomal lipoperoxidation to 84.5% and 68.55% of those of the scalded control rats respectively, and prevented the decrease of liver microsomal cytochrome p-450 content and p-nitroanisole-0-demethylase activity 24 h post-scalding. Effects of silymarin on cardiovascular systen have been studied in this university since 1980. O. O silymarin 800 mg/Kg/d or silybin 600 mg/Kg/d reduced plasma total cholesterol, LDL-C and VLDL-C. They however, enhanced HDL-C in hyperlipenic rats. Further studies showed that silymarin enhanced HDL-C in hyperlipemic rats. Further studies showed that silymarin enhanced HDL-C but didn't affect HDL-C, a property of this component which is beneficial to treatment of atherosclerosis. The results showed silymarin 80 mg or silybin 60 mg decreased in vitro platelet aggregation (porcentagem) in rats. The maximal platelet aggregation induced by ADP declined significantly, and time to reach maximal platelet aggregation and five-minute disaggregation didn't change. In our experiments, iv silybin 22,4 mg/kg lowered the amplitude and duration of diastolic blood pressure (DBP) more than those of systolic (SBP), but the descending aortic blood flow, cardiac contractility and ECG did not change significantly in anesthetized open-chest cats. The results indicated a reduction of peripheral resistance and dilatatory action on the resistant blood vessels. These effects are beneficial to coronary heart disease. We also observed the effects of silybin on morphological change, the release of glutamic oxaloacetate aminotrasferase (GOT) and lactate dehydrogenase (LDH) as well as the radioactivity of 3H-TdR incorporated into DNA in normal cardiac cells and cells infected by coxsackie B5, virus os newborn rats. The results showed that silynin did not affect the morphology of normal cell, and that the pathological change of cells infected by virus was delayed and reduced as compared to control. We have investigated the effect of silybin on synthesis and release of LTs in the cultured porcine cerebral basilar arteries (PCBA). Silybin 100 and 500 µmol/L declined the amounts of LTs released from the PCBA incubsated in the presence of A 23187, AA and indomenthacin. The result suggests that silybin can inhibit the activity of 5-lipoxygenase of cerebral blood vessel and may protect the brain from ischemia.

The effects of superoxide anion on intracellular Ca~(2+) concentration and contractility in cultured bovine aortic smooth muscle cells / 中国药理学通报

AIM To study the effects of superox- ide anion (O ) on Ca2+ homeostasi and contractility in cultured bovine aortic smooth muscle cell. METHODS Using Fura-2 fluorescence technique to determine Ca2+ level and collagen gel contraction system to analyze muscle contractility. RESULTS ATP (10 ?mol? L-1 )-induced Ca2+ transient was smaller in xanthine oxidase treated cells(X/XO) than control. The mean peak increment of [Ca2+ ]i (△[Ca2+ ], peak) and the time integral of the elevated [Ca2+ ], (∫ △[Ca2+ ]i dt) for 5 min were decreased from (206. 1 ? 10.2) to (147.4 ? 14.7) nmol? L-1, and from (12.2 ?0.5) to (9.8 ? 0.8) ?mol?L-1 .s-1. △ [Ca2+ ], peak induced by thapsigargin(1 ?mol. L- 1 ) in Ca2+ -free solution was not affected by X/XO, but was decreased from (27. 3 ? 1 .0) nmol? L－l to (13 .5 ? 1 .0 ) nmol? L- １ in Ca2+ -containing solution be cause of the activation of CRAC(△［Ｃa2+ ], CRAC). X/XO accelerated the velocity of thapsigargin-induced Ca2+ leak from (78.7 ? 3.4) s to (64.8 ? 4.40) s. Gel contraction area in X/XO-treated cells induced by ATP or thapsigargin (in Ca2+ free solution and in Krebs solution) was decreased from 23.6% ? 4.6% to 7.4% ?0.2%, from 3.5% ?0.6% to － l.0% ? 0.5%, and from 7.9% ? l.4% to － 0.5% ? 0.7%, respectively. CONCLUTION O2- attenuats smooth muscle contraction by impairing some of Ca2+ mobilization pathways.

Effects of ranitidine on spontaneous beating and action potential of cultured mycardial cells of neonatal rats / 中国药理学通报

The effects of ranitidine (Ran) on cultured myocardial cells of neonatal rats were observed. Ran 100 ?mol?L-1 took no effect on spontaneous beating rates of cultured myocardial cells, but it decreased the beating rates increased by histamine 10 ?mol?L-1 and did not inhibit the beating rates increased by isoprenaline 2?mol?L-1. Histamine 10?mol?L-1 increased the amplitude, maximal rate of rise and pro-longed action potential duration at 50% (APD50) and 90% (APD90) repolarization. The effect was abolished by Ran 100?mol?L-1. The results suggested that Ran may possess antiarrhythmic action induced by histamine's increase.

PATHOLOGICAL STUDY ON THE MECHANISM OF TUMOURSELECTIVE CYTOCIDAL-ACTION OF TUMOUR NECROSIS FACTOR / 第二军医大学学报

Using light microscope and electron microscope,we observed the morphological changes in the SMMC-7721 human hepatocellular carcinoma cell line after it was exposed to the rabbit tumor necrosis factor (TNF)and the cytocidal effect of TNF on the heterotransplanted human hepatocellular carcinoma (SMMC-7721 cell line).It was found that the changes occurred earlier in the cell membranes than in the nuclei during the course of TNF killing SMMC-7721 cell line and there was no special varieties around the necrotic area in the heterotransplanted human hepatocellular carcinoma in the nude mice as compared with that appearing in SMMC-7721 cell line,In addition, we detected the DNA contents of TNF treated SMMC-7721 cells and control ones, but there was no significant difference of the DNA contents between them.Ace of ding to the results of this study, we think that the mechanism by wluch TNF exerts its tumour-selective killing effect is probably as follows.TNF binds to a specific plasma membrane receptor and then disturbs synthesis or assembly of cell membrane components, leading the changes of cell structure(for example, swollen microvilli, a number of vesicles and small holes on the surface of tumor cells), and the lysis of tumor cells.

METHIONINE-ENKEPHALIN ALTERATION OF MITOGENIC AND MIXED LYMPHOCYTE CULTURE RESPONSES IN ZINC-DEFICIENT MICE / 西安交通大学学报(医学版)

The effects of methionine-enkephalin (M-EnK) on mitogenic and mixed lymphocyte culture (MLC) proliferation of splenocytes from Zn-deficient, restricted and control mice were evaluated. The data from this experiment showed that M-Enk could suppress the responses of splenocyte from th 3 groups to eoncanavalin A(Con A), but less inhibition was observed in the Zn-deficient group. M-Enk could also enhance the responses to Pokeweed Mitogen (PWM) and decrease the response to Lipopolysaceharide (LPS) in all groups. Alteration of proliferative responses to LPS,Con A and FWM was reversible in the presence of 10 ?mol/L naloxone, indicating that the effect of M-Enk on cellular proliferation was mediated by the opioid receptor. In the proliferation of MLC, the response of lymphocytes from Zndeficient mice was increased in the absence of M-Enk and M-Enk could suppress this increased response. It is therefore concluded that Met-Enk can modify the pattern of mitogenic responses and the alteration in Con A and MLC responses can be influenced by zinc deficiency.