• Environmental Mutagens and Carcinogens
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• v.18 no.2
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• pp.98-103
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• 1998

Epigallocatechin gallate (EGCG) was reported to exert weak cytotoxicity against normal healthy cells such as C3H10T1/2 cells, but profound inhibitory effects on the initiation or promotion stage of chemical carcinogenesis in mammary gland, blood and mouse skin. This study was carried out to develop antitumor agents with weak side effects and strong antitumor activity. Human skin melanoma cells (HBT 69) and human oral epitheloid carcinoma cells (OCL 17) were cultured in RPMI-1640 media containing 10% fetal bovine serum, antibiotic, and fungizone. After incubation for 24 hrs, the cells were treated with various amounts of (EGCG) for 48 hrs. The growth inhibitory effects of EGCG in human oral epitheloid carcinoma cells were evaluated by the 3- (4,5-djmethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), neutral red (NR), and sulforhodamine B protein (SRB) assays of colorimetric methods. The light microscopic study was also carried out to observe morphological changes of the treated cells. These results obtained were as follows; 1. Significantly inhibitory effects of EGCG against cultured human oral epithelioid carcinoma cells. 2. Significantly inhibitory effects against cultured human skin melanoma cells treated with 50 $\mu$M EGCG, but decreased inhibitory effects in 100 $\mu$M EGCG. 3. Degenerative changes against cultured human oral epitheloid carcinoma cells. 4. Degenerative changes against human skin melanoma cells treated with 50 UM EGCG, but recovered degenerative changes in 100 $\mu$M EGCG.

• Environmental Mutagens and Carcinogens
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• v.18 no.1
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• pp.37-42
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• 1998

In the present study, we have evaluated cytotoxic effects of the chloroform soluble fraction of the methanolic extract of Perilla frutescens in human oral epitheloid carcinoma cells. The light microscopic study showed morphological changes of the treated cells. Cell membrane damaging activity was measured by the lactate dehydrogenase (LDH) assay and disruptions in cell organelles were determined by 3-(4,5-dime-thylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), neutral red (NR) and sulforhodamine protein B (SRB) of colorimetric assay. These results suggest that Perilla frutescens retains a potential antitumor activity.

• Korean Journal of Medicinal Crop Science
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• v.9 no.1
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• pp.8-14
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• 2001

The purpose of this research was to investigate the effects of extracts from cultured hairy roots of R. undulatum on human kidney epithelial cells. The cytotoxicity was measured by colorimetric assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), neutral red (NR) and sulforhodamine protein B (SRB) with human kidney epithelial cell lines A498. MTT, NR and SRB quantities decreased propotionally in cultured A498 cells treated with the water or chloroform extracts of cultured hairy roots at increasing concentrations. These results suggest that extracts of cultured hairy roots are cytotoxic on human epithelial cells. The cytotoxicity of chloroform fraction was stronger than that of water fraction. The values of $MTT_{50},\;NR_{50}\;SRB_{50}$ of the extracts of chloroform fraction and those of water fraction were measured to be $289.3{\mu}g/ml,\;302.7{\mu}g/ml,\;433.8{\mu}g/ml\;and\;475.8{\mu}g/ml,\;428.3{\mu}g/ml,\;549.5{\mu}g/ml$, in A498 cell line.

• Toxicological Research
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• v.16 no.2
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• pp.173-178
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• 2000

This study was carried out to investigate cytotoxicity of several herbicides (Bentazone, Butachlor. Paraquat and Ethalfluralin) in cultured mouse NIH 3T3 fibroblasts. Tetrazolium (MTT), neutral red (NR) and sulforhodamine protein B (SRB) of the colorimetric assays were performed to evaluate the cytotoxicity on cell organelles. 2 x 10$^4$cell/$m\ell$ of NIH 3T3 fibroblast in each well of 24 multidish were cultured. After 24 hours, the cells were treated with solution (1, 25, 50 or 100 $\mu$M) of each herbicide. After the NIH 3T3 fibroblasts of all groups were cultured in the same condition for 48 hours, MTT, NR and SRB assays were performed to evaluate the cytotoxicity. The light microscopic study was carried out to examine morphological changes of cultured NIH 3T3 fibroblasts. The MTT$_{50}$ of Bentazone, Butachlor, Paraquat and Ethalfluralin were 1560.97 $\mu$M, 56.15 $\mu$M, 3138.81 $\mu$M and 1301.82 $\mu$M, respectively. The NR$_{50}$ of Bentazone, Butachlor. Paraquat and Ethalfluralin were 1763.93 $\mu$M, 45.98 $\mu$M, 1030.85 $\mu$M and 1808.29 $\mu$M, respectively. The SRB$_{50}$ of Bentazone, Butachlor. Paraquat and Ethalfluralin were 1913.38 $\mu$M, 65.30 $\mu$M, 1860.73 $\mu$M and 1086.93 $\mu$M, respectively. The morphological changes of NIH 3T3 fibroblasts showed severe degeneration in Butachlor 50 $\mu$M and 100 $\mu$M concentrations. These results indicate that Butachlor has high cytotoxicity, Bentazone, Paraquat and Ethalfluralin very weak cytotoxicity against NIH 3T3 fibroblasts.lasts.

• Korean Journal of Pharmacognosy
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• v.29 no.1
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• pp.22-27
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• 1998

This study was carried out to develop antitumor agents based on effects of the ethyl acetate soluble fraction of the methanolic extract of Lonicerae flos on human oral epitheloid carcinoma cells. Human oral epitheloid carcinoma cells were cultured in RPMI-1640 media containing 10% fetal bovine serum, antibiotic, and fungizone. After incubation for 24 hrs, the cells were treated with A, B, C, D, and E fractions for 48hrs under the same condition. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazoliumbromide), NR (Neutral red) and SRB (Sulforhodamine B protein) assay were performed. The light microscopic findings were observed by inverted microscope. In MTT assay, fraction B was shown significant antitumor activity (P<0.001), fraction E was shown significant antitumor activities (P<0.05), but the other fractions were not shown. In NR assay, fraction B was shown significant antitumor activity (P<0.001). In SRB assay, fractions B was shown significant antitumor activities (P<0.01). fractions A and D were shown significant antitumor activities (P<0.05). but the other fractions were not shown. In light microscopy. the fraction B of the ethyl acetate soluble fraction of the methanolic extract of Lonicerae flos showed the highest antitumor activity. These finding suggested that fraction B possessed the most antitumorous agent.

• Toxicological Research
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• v.11 no.2
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• pp.229-234
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• 1995

This study was carried out to evaluate the cytotoxicity of cadmium on 3T3 fibroblast and to develop the antidote on 3T3 fibroblast which was injuried by $IC_{50}$ of cadmium. The groups for repaired effects were divided into 7 groups such as medium alone treated group. Cadmium treated $IC_{50}$ groups and 5 experimental groups $(IC_{50}$ cadmium plus $10^{-4}$ concentration of each methanol fraction). After incubation for 48 hrs in the same conditions, MTT (tetrazolium MTT), NR (neutral red) and SRB (sulforhodamine B protein) assay were measured. Light microscopic observations were also investigated. The ethyl acetate fraction of Perilla frutescens showed significantly repaired effect against cadmium cytotoxiclty and this fraction inhibited critical cell regeneration in light microscopy.

• Journal of Microbiology and Biotechnology
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• v.21 no.6
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• pp.590-598
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• 2011

Bacterial assimilation of $CO_2$ into stable biomolecules using electrochemical reducing power may be an effective method to reduce atmospheric $CO_2$ without fossil fuel combustion. For the enrichment of the $CO_2$-fixing bacteria using electrochemical reducing power as an energy source, a cylinder-type electrochemical bioreactor with a built-in anode compartment was developed. A graphite felt cathode modified with neutral red (NR-graphite cathode) was used as a solid electron mediator to induce bacterial cells to fix $CO_2$ using electrochemical reducing power. Bacterial $CO_2$ consumption was calculated based on the variation in the ratio of $CO_2$ to $N_2$ in the gas reservoir. $CO_2$ consumed by the bacteria grown in the electrochemical bioreactor (2,000 ml) reached a maximum of approximately 1,500 ml per week. Time-coursed variations in the bacterial community grown with the electrochemical reducing power and $CO_2$ in the mineral-based medium were analyzed via temperature gradient gel electrophoresis (TGGE) of the 16S rDNA variable region. Some of the bacterial community constituents noted at the initial time disappeared completely, but some of them observed as DNA signs at the initial time were clearly enriched in the electrochemical bioreactor during 24 weeks of incubation. Finally, Alcaligenes sp. and Achromobacter sp., which are capable of autotrophically fixing $CO_2$, were enriched to major constituents of the bacterial community in the electrochemical bioreactor.

• Journal of Korean Neurosurgical Society
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• v.29 no.7
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• pp.853-860
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• 2000

Objective : The purpose of our experimental study was to analysis the advantages and disadvantages in the reversible and irreversible cerebral ischemic models with rats by staining with Neutral Red(NR) solusion, 2% 2,3,5-triphenyltetrazolium chloride(TTC) and Hematoxylin & Eosin(H & E). Methods : We have measured the range of cerebral infarction in the rat to get a suitable ischemic model along the object of study with and without craniectomy. With craniectomy, 9 rats were sacrificed for irreversible cerebral ischemic model by means of ligation at proximal(group I) and distal(group II), and coagulation at proximal(group III) middle cerebral artery. Also, 6 rats were sacrificed for irreversible(group IV) and reversible(group V) cerebral ischemic model using nylon thread without craniectomy. The sizes of infarction were measured by staining the coronal sections of the brain with NR solusion, TTC and H & E. Results : There are no difference of physiological parameters comparing the each group. Cerebral infarction was not observed in group II, but it's volume was largest in group IV. Disadvantages of craniectomy group(I, II, III) are the long duration of operation and cortical damage by procedure. It's advantage is confirmation of the middle cerebral artery occlusion and cessation of blood flow through the operative microscope. In case of ischemic models using nylon thread (group IV, V), it is hard to identify the interruption or recirculation of blood flow through the middle cerebral artery, but the advantage is the simplicity of operative technique which reduces the operation time and minimizes the cerebral damage due to craniectomy. Therefore, it seems important to set up the reversible and irreversible ischemic models by carefully considering advantages and disadvantages listed above. Conclusion : TTC staining seems to be effective since it reflects the histological damage sufficiently and quickly. It is hoped that researches focused on ischemic penumbra, which became popular recently, will be further carried on with use of NR staining, optical microscope and electron microscope.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.2
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• pp.343-347
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• 2002

In order to darify the neuroprotective effect of Gamibojungikki-tang(GBJIKT) water extract on cultured mouse spinal sensory neuron damaged by glucose Oxidase (GO), NR (Neutral Red) assay and LDH (Lactate Dehydrogenase) activity assay were carried out after the cultured mouse spinal sensory neuron were preincubated with various concentrations of GBJIKT water extract for 3 hours prior to exposure of GO. Cell viability of cultured mouse spinal sensory neurons exposed to various concentrations of GO for 8 hours was decreased in a dose-dependent manner. NR/sub 50/ values were 50 mU/ml GO. Cultured mouse spinal sensory neurons in the medium containing various concentration of GO for 8 hours showed increasing of LDH activity. We knew that GO was toxic on cultured spinal sensory neurons. Pretreatment of GBJIKT water extract for 3 hours following GO prevented the GO-induced neurotoxicity such as increasing of LDH activity. These results suggest that GO shows toxic effect on cultured spinal sensory neurons and GBJIKT water extract is highly effective in proecting the neurotoxicity induced by GO.

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.94-100
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• 2010

Zymomonas mobilis was immobilized in a modified graphite felt cathode with neutral red (NR-cathode) and Saccharomyces cerevisiae was cultivated on a platinum plate anode. An electrochemical redox reaction was induced by 3 volts of electric potential charged to the cathode and anode. The Z. mobilis produced 1.3-1.5 M of ethanol in the cathode compartment, whereas the S. cerevisiae produced 1.7-1.9 M in the anode compartment after 96 h. The ethanol produced by the Z. mobilis immobilized in the NR-cathode and S. cerevisiae cultivated on the platinum plate was 1.5-1.6 times higher than that produced under conventional conditions. The electrochemical oxidation potential inhibited Z. mobilis, but activated S. cerevisiae. The SDS-PAGE pattern of the total soluble proteins extracted from the Z. mobilis cultivated under the electrochemical oxidation conditions was gradually simplified in proportion to the potential intensity. Z. mobilis and S. cerevisiae were cultivated in the cathode and anode compartments, respectively, of an electrochemical redox combination system. The Z. mobilis culture cultivated in the cathode compartment for 24 h was continuously transferred to the S. cerevisiae culture in the anode compartment at a rate of 300 ml/day. Approx. 1.0-1.2 M of ethanol was produced by the Z. mobilis in the cathode compartment within 24 h, and an additional 0.8-0.9 M produced by the S. cerevisiae in the anode compartment within another 24 h. Thus, a total of 2.0-2.1 M of ethanol was produced by the electrochemical redox combination of Z. mobilis and S. cerevisiae within 48 h.