• BMB Reports
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• v.46 no.12
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• pp.611-616
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• 2013

Luteolin-7-O-glucoside (LUT7G), a flavone subclass of flavonoids, has been found to increase anti-oxidant and anti-inflammatory activity, as well as cytotoxic effects. However, the mechanism of how LUT7G induces apoptosis and regulates cell cycles remains poorly understood. In this study, we examined the effects of LUT7G on the growth inhibition of tumors, cell cycle arrest, induction of ROS generation, and the involved signaling pathway in human hepatocarcinoma HepG2 cells. The proliferation of HepG2 cells was decreased by LUT7G in a dose-dependent manner. The growth inhibition was due primarily to the G2/M phase arrest and ROS generation. Moreover, the phosphorylation of JNK was increased by LUT7G. These results suggest that the anti-proliferative effect of LUT7G on HepG2 is associated with G2/M phase cell cycle arrest by JNK activation.

• The Journal of the Korean Society for Microbiology
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• v.17 no.1
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• pp.75-85
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• 1982

In order to demonstrate the effect of specific serum IgG antibody on the adherence of Streptococcus mutans to smooth surface and the mechanism of effective adherence inhibition by IgG antibody, in the present study authors obtained purified IgG from different immunogen preparations of S. mutans NCTC 10449(serotype c) and observed the effect of each IgG preparation on the adherence of each S. mutans strain cultured in different conditions. In addition, the present study was undertaken to observe the cross-reactivity of IgG and the effect of sucrose concentration on the adherence of S. mutans in vitro non-growth condition. The adherence of S. mutans to glass surface was effectively inhibited by serum IgG antibody. At the same IgG concentrations, anti-2% fructose grown/1N NaCl washed S. mutans NCTC 10449 cell showed greater adherence inhibitory effect to S. mutans strains than anti-2% sucrose grown and anti-S. mutans NCTC 10449 cell wall, and the greater inhibitory effects of IgG preparations were observed in assay using 2% fructose grown S. mutans cell preparations than using 0.1% sucrose grown cell preparations. These results suggest that the more effective adherence inhibition by serum IgG antibody is due to the reaction with S. mutans cell surface antigens rather than glucan and cell-associated glucosyltransferase. The greatest adherence inhibitory effect of IgG to S. mutans strains was observed on homologous NCTC 10449 strain and the inhibition cross-reactivities were observed between serotype c, e, and f strains. More pronounced cross-reactivity of adherence inhibition of IgG to S. mutans was observed in assay using anti-2% fructose grown/1N NaCl washed cell than using other IgG preparations, and observed in assay using 2% fructose grown S. mutans cell preparations than 0.1% sucrose grown cell preparations. It was interested that low, but adequate concentration of reactive IgG antibody significantly increased the adherence ability of S. mutans. This result may be due to the formation of small cell aggregates resulted in a increase in the numbers of organisms which adhered to glass surface. The adherence of S. mutans to glass surface was possible in the absence of glucan-synthetic activity. Low level of sucrose significantly increased the adherence ability of S. mutans to glass surface, but excessive amount of sucrose induced large cell aggregates resulted in a decrease in the numbers of organism which adhered.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1514-1519
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• 2005

This study was performed to investigate the effects of Porphyra tenera (PT) on cytotoxicity and quinone reductase (QR) activity in the cancer cells. PT was extracted with methanol and further fractionated into five different types: hexane (PTMH), ethyl-ether (PTMEE), ethylacetate (PTMEA) butanol (PTMB) and aquous (PTMA) partition layers. We determined the cytotoxic effect of these layers on C6, HepG2, MCF-7, and HT-29 cell lines by MTT assay. Among the various fractions, hexane (PTMH) of PT showed the strongest cytotoxic effect on C6, HepG2 and MCF-7 cell lines. PTMH displayed very low level of cytotoxicity at the lower concentration levels and at 300 $\mu$g/mL. PTMH resulted in 87.5$\%$ growth inhibition on C6 cell 70 $\%$ on the HepG2 cell and 89$\%$ on the MCF-7 cell, which were significantly high compared to other fractions. A 400 $\mu$g/mL PTMH concentration level, 99$\%$, 94.5$\%$ and 99$\%$ of cell growth inhibition were resulted on the same cell lines. On HT-29 cell line, both hexane (PTMH) and aqueous (PTMA) fraction of PT showed cytotoxic effects, but the Percentage was not as high as previous results tested on other cell lines such as C6 HepG2 and MCF-7 cell lines. Also, we observed quinone reductase (QR) inducing-effects in all fractions of PT on HepG2 cells. The QR inducing effects of the PTMH on HepG2 cells at 150 $\mu$g/mL concentration was 6.6 times higher than the control. Although further studies are needed, the present work suggests that PT was a potential to be used as a chemopreventive.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.69-69
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• 2001

The cell cycle phase in which donor nuclei exist prior to nuclear transfer is an important factor governing developmental rates of reconstituted embryos. It was suggested that quiescent G0 and cycling G1 cells could support normal development of reconstituted embryos. In a quest of optimized donor nuclei treatment prior to nuclear transfer, this study was undertaken to examine the cell cycle characteristics of bovine fetal and adult somatic cells when cultured under a variety of culture treatments and the cell cycle change with the lapse of time after trypsinization. This was archived by measuring the DNA content of cells using flow cytometry, Cultured fetal fibroblast cells, adult skin and muscle cells, and cumulus cells were divided by 3 culture treatments; 1) grown to 60-70% confluency (cycling), 2) serum starved culture, 3) culture to confluency. Trypsinized cells were fixed by 70% ethanol and stained with propidium iodide. For one experiment, trypsinized cells were resuspended in DMEM＋10% FBS and incubated for 1.5, 3 and 6 h with occasional shaking before ethanol fixation. Cell cycle phases were determined by flow cytometry enabling calculation of percentages of G0＋G1, S and G2＋M. The majority of cells were in G0＋Gl stage regardless of origin of cells. Cultures that were serum starved or cultured to confluency contained significantly (P<0.05) higher percentages of cells in G0＋G1 (89.5-95.4%). For every cell lines and culture treatments, percentages of cells in existing in G0＋G1 increased with decreasing of the cell size from large to small. In the serum starved and confluency groups, about 98% of small cells were in G0＋G1 Serum starved culture contained higher percentages of small-sized cells (38.5-66.9%) than cycling and confluent cultures regardless of cell lines (P<0.05). After trypsinization of fetal fibroblast and adult skin cells that were serum starved and cultured to confluency, the percentages of cells in G0＋G1 significantly increased by incubation for 1.5(95.7-99.5%) and 3.0 h (95.9-98.6%). The results suggest that the efficient synchronization of bovine somatic cells in G0＋G1 for nuclear transfer can be established by incubation for a limited time period after trypsinization of serum starved or confluent cells.

• KSBB Journal
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• v.13 no.3
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• pp.259-267
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• 1998

Optimal feeding strategies in bioreactor operation of Scutellaria baicalensis G. plant cell culture were investigated to maximize the production of flavone glycosides by using a structured kinetic model which can predict culture growth and flavone glycosides synthesis in a rigorous, quantitative manner. For the production of baicalin and wogonin-7-0-GA, the strategies for glucose feeding into Scutellaria baicalensis G. plant cell culture were proposed based on the model, which are a periodic fed-batch operation with maintenance of cell viability and of specific production rate respectively, and a perfusion operation with maintenance of specific production rate for baicalin and wogonin-7-0-GA. Simulation results showed that the highest volumetric concentration of flavone glycosides was obtained in a periodic fed-batch operation with maintenance of cell viability among all the suggested strategies. In the periodic fed-batch operations, the higher volumetric production of flavone glycosides was achieved compared with that in the perfusion operation. It can be concluded that a periodic fed-batch operation with maintenance of cell viability would be the optimal and practical operating strategy of Scutellaris baicalensis G. plant cell culture for the production of flavone glycosides.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.525-529
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• 1990

Plant cell cultures of Lithospermum erythrorhizon were performed in stirred tank and packed-bed reactors with in situ extraction by n-hexadecane. The specific shikonin production and volumetric shikonin productivity of stirred tank reactor reached 1.5 mg shikoninlg cell and 400$\mu g$ shikonin/(L.day), respectively. In packed-bed reactor with calcium alginate-immobilized cells specific shikonin production and volumetric productivity reached 2.0 mg shikoninlg cell and 2857$\mu g$ shikonin/(L.day), which were 1.3 and 7.1 times higher than those of stirred tank reactor, respectively. The higher shikonin production and productivity of packed-bed reactor seemed to be due to high cell loading capacity of calcium alginate immobilized cells in packed-bed reactor and improved cell-cell contact.

• KSBB Journal
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• v.9 no.1
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• pp.8-15
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• 1994

The research has been carried out to optimize a recombinant S. cerevisine fermentation process for the production of an anticoagulant hirudin. The structural gene coding for hirudin was combined with the GAL10 promoter for controlled expression, the MFal signal sequence for hirudin secretion, and the GAL7 terminator for transcriptional termination. Growth medium composition and environmental conditions were optimized for maximizing cell growth and final hirudin concentration. The optimized conditions included yeast extract 40g/$\ell$, casamino acid 5g/$\ell$, g1ucose 20g/$\ell$, galactose 30g/$\ell$, DO 50% and temperature $30^{\circ}C$. These conditions yielded the specific cell growth rate of $0.13hr^{-1}$, the final cell density of 30g cell/$\ell$ and the final hirudin concentration of 64mg/$\ell$ in the batch fermentation with a 2.5$\ell$ jar fermentor.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3383-3387
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• 2015

Portulaca oleracea (Family: Portulacaceae), is well known for its anti-inflammatory, antioxidative, anti-bacterial, and anti-tumor activities. However, cytotoxic effects of seed oil of Portulaca oleracea against human liver cancer (HepG2) and human lung cancer (A-549) cell lines have not been studied previously. Therefore, the present study was designed to investigate the cytotoxic effects of Portulaca oleracea seed oil on HepG2 and A-549 cell lines. Both cell lines were exposed to various concentrations of Portulaca oleracea seed oil for 24h. After the exposure, percentage cell viability was studied by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT), neutral red uptake (NRU) assays, and cellular morphology by phase contrast inverted microscopy. The results showed a concentration-dependent significant reduction in the percentage cell viability and an alteration in the cellular morphology of HepG2 and A-549 cells. The percentage cell viability was recorded as 73%, 63%, and 54% by MTT assay and 76%, 61%, and 50% by NRU assay at 250, 500, and $1000{\mu}g/ml$, respectively in HepG2 cells. Percentage cell viability was recorded as 82%, 72%, and 64% by MTT assay and 83%, 68%, and 56% by NRU assay at 250, 500, and $1000{\mu}g/ml$, respectively in A-549 cells. The 100 $100{\mu}g/ml$ and lower concentrations were found to be non cytotoxic to A-549 cells, whereas decrease of 14% and 12% were recorded by MTT and NRU assay, respectively in HepG2 cells. Both HepG2 and A-549 cell lines exposed to 250, 500, and $1000{\mu}g/ml$ of Portulaca oleracea seed oil lost their normal morphology, cell adhesion capacity, become rounded, and appeared smaller in size. The data from this study showed that exposure to seed oil of Portulaca oleracea resulted in significant cytotoxicity and inhibition of growth of the human liver cancer (HepG2) and human lung cancer (A-549) cell lines.

• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.1114-1118
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• 2015

Microbial fuel cells (MFCs) have gathered attention as a novel bioenergy technology to simultaneously treat wastewater with less sludge production than the conventional activated sludge system. In two different operations of the MFC and aerobic process, microbial growth was determined by the protein assay method and their biomass yields using real wastewater were compared. The biomass yield on the anode electrode of the MFC was 0.02 g-COD-cell/gCOD-substrate and the anolyte planktonic biomass was 0.14 g-COD-cell/g-COD-substrate. An MFC without anode electrode resulted in the biomass yield of 0.07 ± 0.03 g-COD-cell/g-CODsubstrate, suggesting that oxygen diffusion from the cathode possibly supported the microbial growth. In a comparative test, the biomass yield under aerobic environment was 0.46 ± 0.07 g-COD-cell/g-COD-substrate, which was about 3 times higher than the total biomass value in the MFC operation.

• Microbiology and Biotechnology Letters
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• v.26 no.5
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• pp.435-441
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• 1998

Optimal conditions for the production of natural color, betacyanin were investigated by varying light intensity, C/N ratio, concentrations of phosphate and kinds of elicitors. Batch cultivation was employed to characterize cell growth and betacyanin production of 32 days. The maximum specific growth rate, ${\mu}$$\sub$max/, was 0.3 (1/day) for batch cultivation. The maximum specific production rate, q$\^$max/$\sub$p/, was enhanced 0.11 (mg/g-cell/day) at 3 klux. A light intensity of 3 klux was shown to the best for both cell growth and betacyanin production. The maximum specific production rate was 0.125 (mg/g-cell/day) at 0.242 (1/day), the maximum specific growth rate. The dependence of specific growth rate on the light lintensity is fit to the photoinhibition model. The correlation between ${\mu}$ and q$\sub$p/ showed that the product formation parameters, ${\alpha}$ and ${\beta}$$\sub$p/ were 0.3756 (mg/cell) and 0.001 (mg/g-cell/day), respectively. The betacyanin production was partially cell growth related process, which is different from the production of a typical product in plant cell cultures. In C/N ratio experiment, high carbon concentration, 42.1 (w/w) improved cell growth rate while lower concentration, 31.6 (w/w) increased the betacyanin production rate. The ${\mu}$$\sub$max/ and q$\^$max/$\sub$p/ were 0.26 (1/day) and 0.075 (mg/g-cell/day), respectively. Beta vulgaris L. cells under 1.25 mM phosphate concentration produced 10.15 mg/L betacyanin with 13.46 (g-dry wt./L) of maximum cell density. The production of betacyanin was elongated by adding 0.1 ${\mu}$M of kinetin. This also increased the cell growth. Optimum culture conditions of light intensity, C/N, phosphate concentration were obtained as 5.5 klux, 27 (w/w), 1.25 mM, respectively by the response surface methodology. The maximum cell density, X$\sub$max/, and maximum production, P$\sub$max/, in optimized conditions were 16 (g-dry wt./L), 12.5 (mg/L) which were higher than 8 (g-dry wt./L), 4.48 (mg/L) in normal conditions. The ${\mu}$$\sub$max/ and q$\^$max/$\sub$p/ were 0.376 (1/day) and 0.134 (mg/g-cell/day) at the optimal condition. The overall results may be useful in scaling up hairy root cell culture system for commercial production of betacyanin.