• Journal of Nutrition and Health
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• 제52권2호
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• pp.157-167
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• 2019

본 연구에서는 ice plant의 ethanol 추출물과 분획물의 항산화 및 대장암세포 성장억제 활성을 in vitro 수준에서 평가하는 것을 목적으로 하였다. Ethanol 추출물의 총 폴리페놀 함량 (3.7 mg GAE/g), 총 카로티노이드 함량 ($13.2{\mu}g/g$), DPPH 라디칼 소거활성 (21.0%), 철 환원력 (21.0%)보다 butanol 분획물의 총 폴리페놀 함량 (5.4 mg GAE/g), 총 카로티노이드 함량 ($86.6{\mu}g/g$), DPPH 라디칼 소거활성 (34.9%), 철 환원력 (80.8%)이 더 높았다. 또한 HCT116 대장암세포에서 세포 내 활성산소종 수준을 감소시키거나 세포 성장을 억제하는데 있어서 ethanol 추출물보다 butanol 분획물의 활성이 더 컸다. 대장암세포의 성장을 억제하는데 있어서 butanol 분획물이 ethanol 추출물보다 더 효과적이었던 것은 butanol 분획물의 apoptosis 유도활성이 ethanol 추출물의 활성보다 더 컸고 butanol 분획물만이 G2/M기억류활성을 나타냈기 때문인 것으로 생각된다. 앞으로 이와 같은 결과를 초래하는 주요 활성성분을 분리 동정하고 ice plant의 항산화 활성 및 대장암세포 성장억제 효과가 in vivo 수준에서 재현되는지 검증하며 이와 관련된 세부기전을 탐색하는 심도 있는 연구가 필요할 것으로 생각된다.

• Journal of Photoscience
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• 제9권2호
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• pp.229-232
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• 2002

There are two distinct UV-responsive signaling pathways in UV-irradiated mammalian cells, i.e., the DNA damage-dependent and -independent pathways. The former occurs in nucleus and results in growth arrest and apoptosis via post-translational modification of p53. The latter is initiated by oxidative stress and/or by damages in cell membrane or cytoplasm, which activate signaling cascade through intracellular molecules including mitogen activated protein kinases (MAPK). In normal human fibroblastic cells, all of MAPK family members, extracellular signal-related kinases (ERK), c-Jun N-terminal kinases (JNK) and p38, were rapidly phosphorylated following UV-irradiation. ERK phosphorylation was suppressed by an inhibitor of receptor tyrosine kinases (RTK). As ERK usually responds to mitogenic stimuli from RTK ligands, UV-induced ERK phosphorylation may be linked to the proliferation of survived cells. In contrast, phosphorylation of JNK and p38, as well as apoptosis, were modulated by the level of UV-generated oxidative stress Therefore, JNK and p38 may take part in oxidative stress-mediated apoptosis. Phosphorylation of p53 at Ser and Thr residues are essential for stabilization and activation of p53. Among several sites reported, we confirmed phosphorylation at Ser-15 and Ser-392 after UV-irradiation. Both of these were inhibited by a phosphoinositide 3-kinase inhibitor, presumably due to the shutdown of signals from DNA damage to p53. Phosphorylation at Ser-392 was also sensitive to an antioxidant and a p38 inhibitor, suggesting that Ser-392 of p53 is one of the possible points where DNA damage-dependent and -independent apoptic signals merge. Thus, MAPK pathway links UV-induced intracellular signals to the nuclear responses and modifies DNA damage-dependent cellular outcome, resulting in the determination of cell death.

• Parasites, Hosts and Diseases
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• 제54권2호
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• pp.139-145
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• 2016

Toxoplasmosis is a serious disease caused by Toxoplasma gondii, one of the most widespread parasites in the world. Lipid metabolism is important in the intracellular stage of T. gondii. Stearoyl-CoA desaturase (SCD), a key enzyme for the synthesis of unsaturated fatty acid is predicted to exist in T. gondii. Sterculic acid has been shown to specifically inhibit SCD activity. Here, we examined whether sterculic acid and its methyl ester analogues exhibit anti-T. gondii effects in vitro. T. gondii-infected Vero cells were disintegrated at 36 hr because of the propagation and egress of intracellular tachyzoites. All test compounds inhibited tachyzoite propagation and egress, reducing the number of ruptured Vero cells by the parasites. Sterculic acid and the methyl esters also inhibited replication of intracellular tachyzoites in HFF cells. Among the test compounds, sterculic acid showed the most potent activity against T. gondii, with an $EC_{50}$ value of $36.2{\mu}M$, compared with $EC_{50}$ values of $248-428{\mu}M$ for the methyl esters. Our study demonstrated that sterculic acid and its analogues are effective in inhibition of T. gondii growth in vitro, suggesting that these compounds or analogues targeting SCD could be effective agents for the treatment of toxoplasmosis.

• Molecular & Cellular Toxicology
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• 제3권4호
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• pp.292-298
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• 2007

Zinc plays indispensable roles in metabolism, including cell growth, apoptosis, proliferation and differentiation. Kidneys are target organs for various regulators of mineral metabolism, and play a key role in zinc balance. To investigate the zinc uptake efficiency, we examined the zinc uptake and accumulation level in vivo and in vitro study. Plasma zinc concentration was peaked out at 1 hr after oral zinc administration. The renal zinc level was peaked out at 12 hr after oral zinc administration, and it was the highest in 40 mg/kg Zn-Asp administrated group in comparison with other groups. In addition, the m-RNA expression level of zinc transporter-1 (ZnT-1), zinc transporter-2 (ZnT-2) and high-affinity L-aspartate transporter (EAAT-3) in Zn-Asp administered group were increased compared with control groups and $ZnSO_4$ group. In order to investigate the intracellular zinc uptake mechanism, we performed the in vitro study by using human embryonic kidney cell line, HEK 293. Intracellular zinc level was peaked out at 3 hr after zinc treatment. In the same way, the mRNA expression level of ZnT-1 and EAAT-3 were increased compared with control group. This study showed that Zn-Asp is effective the zinc uptake into the kidney by increasing the zinc transporter expression.

• IMMUNE NETWORK
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• 제3권4호
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• pp.268-275
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• 2003

Background: Hemopoietic cells require the constant presence of growth factors for survival in vitro and in vivo. Caspases have been known as central executors of apoptotic cell death. We have, therefore, investigated the pathways that regulate caspase activity and apoptosis using the $CD34^+$ cell line, TF-1 which requires GM-CSF for survival. Methods: Apoptosis was measured by annexin V staining and mitochondrial membrane potential was measured by DiOC6 labelling. Intracellular pH was measured using pH sensitive fluorochrome, BCECF or SNARF-1, followed by flow cytometry analysis. Caspase activation was analyzed by PARP cleavage using anti-PARP antibody. Results: Removal of GM-CSF induceed PARP cleavage, a hallmark of caspase activity, concomitant with pHi acidification and a drop in mitochondrial potential. Treatment with ZVAD, a competitive inhibitor of caspases, partially rescued cell death without affecting pHi acidification and the reduction of mitochondrial potential, suggesting that both these events act upstream of caspases. Overexpression of Bcl-2 prevented cell death induced by GM-CSF deprivation as well as pHi acidification and the reduction in mitochondrial membrane potential. In parental cells maintained with GM-CSF, EIPA, a competitive inhibitor of $Na^+/H^+$ antiporter induced apoptosis, accompanied by a drastic reduction in mitochondrial potential. In contrast, EIPA induced apoptosis in Bcl-2 transfectants without causing mitochondrial membrane depolarization. Conclusion: Taken together, our results suggest that the regulation of $H^+$fluxes, either through a mitochondriondependent or independent pathway, is central to caspase activation and apoptosis.

• Asian Pacific Journal of Cancer Prevention
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• 제15권7호
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• pp.3211-3217
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• 2014

Background: The current study investigated the effects of Piper longumine on radio-sensitization of human breast cancer MDA-MB-231 cells and underlying mechanisms. Materials and Methods: Human breast cancer MDA-MB-231 cells were cultured in vitro and those in logarithmic growth phase were selected for experiments divided into four groups: control, X-ray exposed, Piper longumine, and Piper longumine combined with X-rays. Conogenic assays were performed to determine the radio-sensitizing effects. Cell survival curves were fitted by single-hit multi-target model and then the survival fraction (SF), average lethal dose ($D_0$), quasi-threshold dose ($D_q$) and sensitive enhancement ratio (SER) were calculated. Cell apoptosis was analyzed by flow cytometry (FCM). Western blot assays were employed for expression of apoptosis-related proteins (Bc1-2 and Bax) after treatment with Piper longumine and/or X-ray radiation. The intracellular reactive oxygen species (ROS) level was detected by FCM with a DCFH-DA probe. Results: The cloning formation capacity was decreased in the group of piperlongumine plus radiation, which displayed the values of SF2, D0, Dq significantly lower than those of radiation alone group and the sensitive enhancement ratio (SER) of D0 was1.22 and 1.29, respectively. The cell apoptosis rate was increased by the combination treatment of Piper longumine and radiation. Piper longumine increased the radiation-induced intracellular levels of ROS. Compared with the control group and individual group, the combination group demonstrated significantly decreased expression of Bcl-2 with increased Bax. Conclusions: Piper longumine at a non-cytotoxic concentration can enhance the radio-sensitivity of MDA-MB-231cells, which may be related to its regulation of apoptosis-related protein expression and the increase of intracellular ROS level, thus increasing radiation-induced apoptosis.

• Animal Bioscience
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• 제36권7호
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• pp.1120-1129
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• 2023

Objective: This study aimed to determine the protective efficacy of Buddha's Temple (BT) extract against tert-butyl hydroperoxide (t-BHP)-induced oxidative stress in Gallus gallus chicken embryo fibroblast cell line (DF-1) and its effects on the cell lipid metabolism. Methods: In this experimental study, Gallus gallus DF-1 fibroblast cells were pretreated with BT 10^-7 for 24 hours, followed by their six-hour exposure to t-BHP (100 μM). Water-soluble tetrazolium salt-8 (WST-8) assays were performed, and the growth curve was computed. The intracellular gene expression changes caused by BT extract were confirmed through quantitative polymerase chain reaction (qPCR). Flow cytometry, oil red O staining experiment, and thin-layer chromatography were performed for the detection of intracellular metabolic mechanism changes. Results: The WST-8 assay results showed that the BT pretreatment of Gallus gallus DF-1 fibroblast cell increased their cell survival rate by 1.08%±0.04%, decreased the reactive oxygen species (ROS) level by 0.93%±0.12% even after exposure to oxidants, and stabilized mitochondrial activity by 1.37%±0.36%. In addition, qPCR results confirmed that the gene expression levels of tumor necrosis factor α (TNFα), TIR domain-containing adapter inducing IFN-beta (TICAM1), and glucose-regulated protein 78 (GRP78) were regulated, which contributed to cell stabilization. Thin-layer chromatography and oil red O analyses showed a clear decrease in the contents of lipid metabolites such as triacylglycerol and free fatty acids. Conclusion: In this study, we confirmed that the examined BT extract exerted selective protective effects on Gallus gallus DF-1 fibroblast cells against cell damage caused by t-BHP, which is a strong oxidative inducer. Furthermore, we established that this extract significantly reduced the intracellular ROS accumulation due to oxidative stress, which contributes to an increase in poultry production and higher incomes.

• Journal of Microbiology and Biotechnology
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• 제7권5호
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• pp.287-292
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• 1997

The role of glyoxylate bypass in lysine production by Corynebacterium glutamicum ssp. lactofermentum ATCC21799 was analyzed by using cloned aceA and aceB genes which encode enzymes catalyzing the bypass. Introduction of a plasmid carrying aceA and aceB to the strain increased enzyme activities of the bypass to approximately 5 fold on acetate minimal medium. The strain with amplified glyoxylate bypass excreted 25% more lysine to the growth medium than the parental strain, apparently due to the increased availability of intracellular oxaloacetate. The final cell yield was lower in the strain with amplified glyoxylate bypass. These changes were specific to the lysine-producing C. glutamicum ssp. lactofermentum ATCC21799, since the lysine-nonproducing wild type Corynebacterium glutamicum strain grew faster and achieved higher cell yield when the glyoxylate bypass was amplified. These findings suggest that the lysine producing C. glutamicum ssp. lactofermentum ATCC21799 has the ability to efficiently channel oxaloacetate, the TCA cycle intermediate, to the lysine biosynthesis pathway whereas lysine-nonproducing strains do not. Our results show that amplification of the glyoxylate bypass efficiently increases the intracellular oxaloacetate in lysine producing Corynebacterium species and thus results in increased lysine production.

• IMMUNE NETWORK
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• 제1권1호
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• pp.14-25
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• 2001

Background: Bone marrow stromal cells (BMSCs) express many cell surface molecules, which regulate the proliferation and differentiation of immune cells within the bone marrow. Methods: To identify cell surface molecules, which can regulate cell proliferation through cell interaction, monoclonal antibodies (MoAbs) against BMSCs were produced. Among them, 1H8 MoAb, which recognized distinctly an 80 kDa protein, abolished myeloma cell proliferation that was induced by co-culturing with BMSCs. Results: IL-6 gene expression was increased when myeloma or stromal cells were treated with 1H8 MoAb. In addition, the expression of IL-6 receptor and CD40 was up-regulated by 1H8 treatment, suggesting that the molecule recognized by 1H8 MoAb is involved in cell proliferation by modulating the expression of cell growth-related genes. Myeloma cells contain high levels of reactive oxygen species (ROS), which are related to gene expression and tumorigenesis. Treatment with 1H8 decreased the intracellular ROS level and increased PAG antioxidant gene concomitantly. Finally, 1H8 induced the tyrosine phosphorylation of several proteins in U266. Conclusion: Taken together, 1H8 MoAb recognized the cell surface molecule and triggered the intracellular signals, which led to modulate gene expression and cell proliferation.

• 대한한방부인과학회지
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• 제28권2호
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• pp.1-14
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• 2015

Objectives : This study was designed to investigate the effects of Taraxaci Herba (TH) on cell death in breast cancer cells. Methods : In this experiment, the effects of TH on proliferation rates, cell morphology and growth pattern, intracellular reactive oxygen species (ROS) production. In addition, the effects on nuclear condensation, fragmentation and formation of acidic vesicular organelles (AVO) in MCF-7 cells were also investigated. Finally, autophagy related with protein was observed by using western blot method. Results : TH inhibited proliferation of MCF-7 cells, TH elevated intracellular ROS levels significantly. Treatment with TH did not affect nuclear morphologies such as condensation or fragmentation. On the other hand, TH treatment effectively induced AVO. Finally, one of autophagy related with protein, Microtubule-associated proteins 1A/1B light chain 3A (MAP1LC3A, LC3) level was elevated by treatment with TH. Conclusions : These data indicate that TH is able to be used for patient with breast cancer and mechanisms are involved in autophagy through ROS generation.