• Restorative Dentistry and Endodontics
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• v.35 no.4
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• pp.285-294
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• 2010

The purpose of this study was to evaluate the viability of periodontal ligament cells of rat teeth after low-temperature preservation under high pressure by means of MTT assay, WST-1 assay. 12 teeth of Sprague-Dawley white female rats of 4 week-old were used for each group. Both side of the first and second maxillary molars were extracted as atraumatically as possible under tiletamine anesthesia. The experimental groups were group 1 (Immediate extraction), group 2 (Slow freezing under pressure of 3 MPa), group 3 (Slow freezing under pressure of 2 MPa), group 4 (Slow freezing under no additional pressure), group 5 (Rapid freezing in liquid nitrogen under pressure of 2 MPa), group 6 (Rapid freezing in liquid nitrogen under no additional pressure), group 7 (low-temperature preservation at $0^{\circ}C$ under pressure of 2 MPa), group 8 (low-temperature preservation at $0^{\circ}C$ under no additional pressure), group 9 (low-temperature preservation at $-5^{\circ}C$ under pressure of 90 MPa). F-medium and 10% DMSO were used as preservation medium and cryo-protectant. For cryo-preservation groups, thawing was performed in $37^{\circ}C$ water bath, then MTT assay, WST-1 assay were processed. One way ANOVA and Tukey HSD method were performed at the 95% level of confidence. The values of optical density obtained by MTT assay and WST-1 were divided by the values of eosin staining for tissue volume standardization. In both MTT and WST-1 assay, group 7 ($0^{\circ}C$/2 MPa) showed higher viability of periodontal ligament cells than other group (2-6, 8) and this was statistically significant (p < 0.05), but showed lower viability than group 1, immediate extraction group (no statistical significance). By the results of this study, low-temperature preservation at $0^{\circ}C$ under pressure of 2 MPa suggest the possibility for long term preservation of teeth.

• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.356-363
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• 2009

The purpose of this study was to evaluate the viability of periodontal ligament cells in rat teeth using slow cryo-preservation method under pressure by means of MTT assay and WST-1 assay. Eighteen teeth of Sprague-Dawley white female rats of 4 week-old were used for each group. Both sides of the first and second maxillary molars were extracted as atraumatically as possible under Tiletamine anesthesia. The experimental groups were group 1 (Immediate control), group 2 (Cold preservation at $4^{\circ}C$for 1 week), group 3 (Slow freezing), group 4 (Slow freezing under pressure of 3 MPa). F-medium and 10% DMSO were used as preservation medium and cryo-protectant. For cryo-preservation groups, thawing was performed in $37^{\circ}C$water bath, then MTT assay and WST-1 assay were processed. One way ANOVA and Tukey method were performed at the 95% level of confidence. The values of optical density obtained by MTT assay and WST-1 were divided by the values of eosin staining for tissue volume standardization. In both MTT and WST-1 assay, group 4 showed significantly higher viability of periodontal ligament cells than group 2 and 3 (p < 0.05), but showed lower viability than immediate control group. By the results of this study, slow cryo-preservation method under pressure suggests the possibility for long term cryo-preservation of the teeth.

• Restorative Dentistry and Endodontics
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• v.39 no.1
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• pp.39-44
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• 2014

Objectives: The purpose of this study was to evaluate in vitro cytotoxicity of the pozzolan cement and other root-end filling materials using human periodontal ligament cell. Materials and Methods: Endocem (Maruchi), white ProRoot MTA (Dentsply), white Angelus MTA (Angelus), and Super EBA (Bosworth Co.) were tested after set completely in an incubator at $37^{\circ}C$ for 7 days, Endocem was tested in two ways: 1) immediately after mixing (fresh specimens) and 2) after setting completely like other experimental materials. The methods for assessment included light microscopic examination, cell counting and WST-1 assay on human periodontal ligament cell. Results: In the results of microscopic examination and cell counting, Super EBA showed significantly lower viable cell than any other groups (p < 0.05). As the results of WST-1 assay, compared with untreated control group, there was no significant cell viability of the Endocem group. However, the fresh mixed Endocem group had significantly less cell viability. The cells exposed to ProRoot MTA and Angelus MTA showed the highest viability, whereas the cells exposed to Super EBA displayed the lowest viability (p < 0.05). Conclusions: The cytotoxicity of the pozzolan cement (Endocem) was comparable with ProRoot MTA and Angelus MTA. Considering the difficult manipulation and long setting time of ProRoot MTA and Angelus MTA, Endocem can be used as the alternative of retrofilling material.

• Journal of Sensor Science and Technology
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• v.32 no.6
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• pp.412-417
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• 2023

There is increasing interest in the rapid and highly sensitive monitoring of cell viability in biological and toxicological research. Conventional methods depend on optical assays using Water Soluble Tetrazolium-8 (WST-8) or 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay, which requires a large volume of samples and special instruments, necessitating shipment of clinical samples to laboratories. This paper reports on the development of a rapid and sensitive electrochemical (EC) sensor using screen printed electrode (SPE) and surface modification using 4'-mercapto-N-phenylquinone diamine (4'-NPQD), as double electron mediators, for monitoring cell viability via the measurement of nicotinamide adenine dinucleotide (NADH). We used the sensor to observe the viability of MCF-7 and doxorubicin (Dox)-treated cells. The oxidation current of NADH was measured via chronoamperometry (CA), and the EC results showed a good linear relationship when compared with NADH quantification using WST-8 assay. The analysis time was only 10 s and limit of detection (LOD) of NADH was 1.78 µM. Our EC method has the potential to replace conventional WST assays for cell viability and cytotoxicity experiments.

• Journal of Acupuncture Research
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• v.25 no.2
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• pp.75-89
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• 2008

목적 : 후박(厚朴)(Magnolia obovata)에서 추출한 낮은 농도의 obovatol 약침액의 RAW264.7 세포에서 LPS로 유발된 염증, $TNF-{\alpha}$로 유발된 human colon carcinoma SW620 및 HCT116 세포의 세포증식에 대한 영향과 그 기전을 살펴보고자 하였다. 방법 : RAW264.7 세포에서 LPS로 염증을 유발하고 낮은 농도의 obovatol 약침액을 처리한 후 cell viability, NO 생성량, iNOS와 COX-2의 발현, $NF-{\kappa}B$활성, 전사능력을 관찰하기 위해 WST-1 assay, NO determination assay, western blot analysis, EMSA, luciferase activity assay를 시행하였고, HCT116, SW620 세포에 $TNF-{\alpha}$로 증식을 유도하고 낮은 농도의 obovatol 약침액을 처리한 후 cell growth, apoptosis 및 apoptosis와 연관된 $NF-{\kappa}B$의 활성 변화를 관찰하기 위해 WST-1, Cell morphogy test, DAPI staining and TUNEL assay, EMSA, luciferase activity assay를 시행하였다. 결과 : 1. RAW264.7 세포에서 낮은 농도의 obovatol 약침액 처리는 $NF-{\kappa}B$의 활성 및 전사능력을 낮추고 iNOS와 COX-2의 발현과 NO 생성을 감소시켜 LPS로 유발된 염증을 억제하였다. 2. HCT116, SW620 세포에서 낮은 농도의 obovatol 약침액 처리는 $NF-{\kappa}B$의 활성을 낮추어 세포자멸사를 촉진함으로써 $TNF-{\alpha}$로 유발된 암세포의 성장을 억제하였다. 결론 : 이상의 결과는 낮은 농도의 obovatol 약침액이 항염 및 인간 전립선암세포주인 SW620, HCT116에 대한 증식억제 효과가 있음을 입증한 것이며, 향후 이를 바탕으로 한 생체 연구에서의 긍정적인 결과는 obovatol 약침액이 만성염증성 질환 및 대장암의 예방과 치료에 대한 효과적인 치료제 개발에 초석이 될 것으로 기대된다.

• Journal of Korean society of Dental Hygiene
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• v.14 no.5
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• pp.775-781
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• 2014

Objectives : The purpose of the study is to investigate the protective effect of coenzyme $Q_{10}$ on cytotoxicity effect of dental monomers in odontoblast(MDPC-23). Methods : MDPC-23 was incubated with the(co)monomers triethylene glycol dimethacrylate (TEGDMA) with and without addition of coenzyme $Q_{10}$. The cell proliferation and survival was determined using WST-1 assay. The level of reactive oxygen species(ROS) was measured by immunofluorescent staining for DCF-DA. Results : TEGDMA treatment decreased the cell proliferation by dose dependently(0.1, 1, 2.5, 5, 10 mM) on the growth of MDPC-23 cells. Coenzyme $Q_{10}$ showed cell proliferation from 5 to $500{\mu}M$ by WST-1 assay. Pre-treatment coenzyme $Q_{10}$ showed the antioxidant effect on proliferation and viability of MDPC-23 after 48h(p<0.05). The positive cells were observed in non-coenyme $Q_{10}$ treatment group(group 2) in comparison with coenyme $Q_{10}$ pre-treatment group(group 1) by DCF-DA. The fluorescence positive cells showed 14.715(group 1) and 19.788(group 2) using image J system. Conclusions : TEGDMA induced cytotoxicity. The MDPC-23 cell death was associated with the increasing ROS. Coenyme $Q_{10}$ showed the antioxidant effects by decreasing ROS. This effects may contribute to the treatment of periodontal disease induced by TEGDMA after operation.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.5
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• pp.857-862
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• 2011

The purpose of this study is to investigate the anti-proliferative mechanism by Trichosanthes kirilowii (TCK) in MCF-7 human breast carcinoma cell. In this study, we used human breast cancer cell line, Michigan cancer foundation-7 cells (MCF-7 cells). They were co-incubated with 30~200 ${\mu}g$/ml TCK for 48 hours, and cell viability was measured by Water-soluble tetrazolium salt-1 (WST-1) assay. After MCF-7 cells were exposed to 60 ${\mu}g$/ml of TCK for 0, 3, 6, 12, 24, 48 hours, We performed flow analysis cytometry sorting(FACS) and western blot analysis. We investigated the effect of dose-dependent cell growth inhibition by TCK, which could be proved by WST-1 assay. Also, flow cytometry analysis showed that TCK increased percentage of subG1 phase and G2/M phase cell cycle. In addition, TCK induced apoptosis through the expression of caspase-9, -3 and poly(ADP-ribose) polymerase(PARP) activation. Moreover, we showed that ATM-dependent G2/M phase arrest by DNA damage and phosphorylation of chk2, cdc25C, cdc2(Tyr15). Taken together, these results suggest that by G2/M phase arrest through DNA damage and inducing of apoptosis through intrinsic pathway, TCK may have potential tumor suppressor in breast cancer.

• Journal of Korean society of Dental Hygiene
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• v.15 no.4
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• pp.719-725
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• 2015

Objectives: The purpose of this study was to determine the toxic effects of sodium lauryl sulfate(SLS) in human keratinocyte HaCaT cells and mouse fibroblast NIH-3T3 cells. Methods: The effect of sodium lauryl sulfate(SLS) cell viability and proliferation were determined by WST-1 assay and changes shape of nucleus were evaluated by Hoechst staining under fluorescence microscopy. Additionally, observation of cell morphological changes under light microscopy. Results: SLS induced cytotoxicity and a marked apoptosis in both HaCaT and NIH-3T3 cell lines. With the result of the WST-1 assay, SLS induced the cytotoxicity of 0.005% and 0.0075%, 0.01% SLS for 24 h after HaCaT and NIH-3T3 cells in time and dose-dependent manner(p<0.005). SLS inhibited cell growth and caused apoptosis as evidenced by nuclear fragmentation and condensation. Thus, determination of the morphological changes to define apoptosis was visualized using inverted phase contrast microscopy. Conclusions: SLS had toxicity of the human keratinocyte cells and mouse fibroblast cells and this study will provide the basic data for the development of proper SLS concentration in dentifrice.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.163-170
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• 2001

Purpose : The measurement of radiation survival using a clonogenic assay, the established standard, can be difficult and time consuming. In this study, We have used the MTT assay, based on the reduction of a tetrazolium salt to a purple formazan precipitate by living cells, as a substitution for clonogenic assay and have examined the optimal condition for performing this assay in determination of radiation sensitivity. Materials and Methods : Four human cancer cell lines - PCI-1, SNU-1066, NCI-H630 and RKO cells have been used. For each cell line, a clonogenic assay and a MTT assay using Premix WST-1 solution, which is one of the tetrazolium salts and does not require washing or solubilization of the precipitate were carried out after irradiation of 0, 2, 4, 6, 8, 10 Gy. For clonogenic assay, cells in $25\;cm^2$ flasks were irradiated after overnight incubation and the resultant colonies containing more than 50 cells were scored after culturing the cells for $10\~14$ days. For MTT assay, the relationship between absorbance and cell number, optimal seeding cell number, and optimal timing of assay was determined. Then, MTT assay was performed when the irradiated cells had regained exponential growth or when the non-irradiated cells had undergone four or more doubling times. Results : There was minimal variation in the values gained from these two methods with the standard deviation generally less than $5\%$, and there were no statistically significant differences between two methods according to t-test in low radiation dose (below 6 Gy). The regression analyses showed high linear correlation with the $R^2$ value of $0.975\~0.992$ between data from the two different methods. The optimal cell numbers for MTT assay were found to be dependent on plating efficiency of used cell line. Less than 300 cells/well were appropriate for cells with high plating efficiency (more than $30\%$). For cells with low plating efficiency (less than $30\%$), 500 cells/well or more were appropriate for assay. The optimal time for MTT assay was after 6 doubling times for the results compatible with those of clonogenic assay, at least after 4 doubling times was required for valid results. In consideration of practical limits of assay (12 days, in this study) cells with doubling time more than 3 days were inappropriate for application. Conclusion : In conclusion, it is found that MTT assay can successfully replace clonogenic assay of tested cancer cell lines after irradiation only if MTT assay was undertaken with optimal assay conditions that included plating efficiency of each cell line and doubling time at least.

• Molecular & Cellular Toxicology
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• v.4 no.2
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• pp.157-163
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• 2008

Formation of ${\beta}$-amyloid $(A{\beta})$ fibrils has been identified as one of the major characteristics of Alzheimer's disease (AD). Inhibition of $A{\beta}$ fibril formation in the CNS would be attractive therapeutic targets for the treatment of AD. Several small compounds that inhibit amyloid formation or amyloid neurotoxicity in vitro have been known. Citrate has surfactant function effect because of its molecular structure having high anionic charge density, in addition to the well-known antibacterial and antioxidant properties. Therefore, we hypothesized that citrate might have the inhibitory effect against $A{\beta}$ fibril formation in vitro and have the protective effect against $A{\beta}$-induced neurotoxicity in PC12 cells. We examined the effect of citrate against the formation of $A{\beta}$ fibrils by measuring the intensity of fluorescence in thioflavin-T (Th-T) assay of between $A{\beta}_{25-35}$ groups treated with citrate and the control with $A{\beta}_{25-35}$ alone. The neuroprotective effect of citrate against $A{\beta}$-induced toxicity in PC12 cells was investigated using the WST-1 assay. Fluorescence spectroscopy showed that citrate inhibited dose-dependently the formation of $A{\beta}$ fibrils from ${\beta}$-amyloid peptides. The inhibition percentages of $A{\beta}$ fibril formation by citrate (1, 2.5, and 5 mM) were 31%, 60%, and 68% at 7 days, respectively in thioflavin-T (Th-T) assay. WST-1 assay revealed that the toxic effect of $A{\beta}_{25-35}$ was reduced, in a dose-dependent manner to citrate. The percentages of neuroprotection by citrate (1, 2.5, and 5 mM) against $A{\beta}-induced$ toxicity were 19%, 31 %, and 34%, respectively. We report that citrate inhibits the formation of $A{\beta}$ fibrils in vitro and has neuroprotective effect against $A{\beta}$-induced toxicity in PC12 cells. Neuroprotective effects of citrate against $A{\beta}$ might be, to some extent, attributable to its inhibition of $A{\beta}$ fibril formation. Although the mechanism of anti-amyloidogenic activity is not clear, the possible mechanism is that citrate might have two effects, salting-in and surfactant effects. These results suggest that citrate could be of potential therapeutic value in Alzheimer's disease.