• Nutritional Sciences
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• 제9권1호
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• pp.3-8
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• 2006

Functional damage to microvascular endothelial cells by hyperglycemia is thought to be one of the critical risk factor.; in the impaired wound healing seen with diabetes mellitus. It is also thought that oxidative stress plays a significant role in this endothelial cell dysfunction. The present study examined the differential effects of flavonoids on endothelial cell dysfunction under high glucose conditions. Human endothelial cells exposed to 30 mmol/L glucose for 7 d were pre-treated with various flavonoids and pulse-treated with 0.2 mmol/L $H_2O_2$ for 30 min. High glucose markedly decreased cell viability with elevated oxidant generation and nuclear condensation. $H_2O_2$ insult exacerbated endothelial cytotoxicity due to chronic exposure to high glucose. (-)Epigallocatechin gallate and quercetin improved glucose-induced cell damage with the disappearnnce of apoptotic bodies, whereas apigenin intensified the glucose cytotoxicity. In addition, cell viability data revealed that these flavonoids of (-)epigallocatechin gallate and quercetin substantially attenuated both high glucose- and $H_2O_2$- induced dual endothelial damage. These results suggest that (-)epigallocatechin gallate and quercetin may be beneficial agents for improving endothelial cell dysfunction induced by high glucose and may prevent or reduce the development of diabetic vascular complications.

• 대한한방부인과학회지
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• 제21권3호
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• pp.18-33
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• 2008

Purpose: The research is to investigate the effect of TFE on apoptosis of human-derived breast cancer cells, to find out the relationship with apoptosis. Methods: Human-derived breast adenocarcinoma cell line, MCF-7 cells were treated by TFE with various concentration. The inducement effect of TFE on cell apoptosis was observed with MTT assay and the relationship between the treatment and apoptosis was investigated with FACS analysis, TUNEL assay and DNA laddering assay and the change in the protein levels of PARP and caspase-3 activities were also observed. The release of cytochrome-c was observed to find out the pathway of apoptosis induced by TFE. Results: The cell apoptosis was significantly induced in MCF-7 cells treated with TFE in concentration-dependent and time-dependent manner. It was verified by FACS analysis, TUNEL assay, DNA laddering assay that cell-death was caused not by necrosis but by apoptosis. The activity of PARP and caspase were increased concentration-dependently. The release of cytocrome-c was decreased in proportion to the concentration of the fruit extract. It therefore demonstrated that mitochondria were involved in apoptosis induced by TFE. The appearance of Bcl-2 protein was decreased concentration-dependently. Conclusion: The treatment by TFE induced apoptosis of human breast adenocarcinoma cell line, MCF-7. It seems likely that cell-death was caused by apoptosis and mitochondria were involved in it. The mechanism of protein change causing apoptosis seems related to the inhibition of Bcl-2 protein, the promotion of inversion from cytochrome-c into cytosol, the activation of caspase and the promotion of PARP cleavage.

• Journal of Microbiology and Biotechnology
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• 제31권4호
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• pp.559-569
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• 2021

As one of the major types of lung cancer, non-small cell lung cancer (NSCLC) accounts for the majority of cancer-related deaths worldwide. Treatments for NSCLC includes surgery, chemotherapy, and targeted therapy. Among the targeted therapies, resistance to inhibitors of the epidermal growth factor receptor (EGFR) is common and remains a problem to be solved. MET (hepatocyte growth factor receptor) amplification is one of the major causes of EGFR-tyrosine kinase inhibitor (TKI) resistance. Therefore, there exists a need to find new and more efficacious therapies. Deoxypodophyllotoxin (DPT) extracted from Anthriscus sylvestris roots exhibits various pharmacological activities including anti-inflammation and anti-cancer effects. In this study we sought to determine the anti-cancer effects of DPT on HCC827GR cells, which are resistant to gefitinib (EGFR-TKI) due to regulation of EGFR and MET and their related signaling pathways. To identify the direct binding of DPT to EGFR and MET, we performed pull-down, ATP-binding, and kinase assays. DPT exhibited competitive binding with ATP against the network kinases EGFR and MET and reduced their activities. Also, DPT suppressed the expression of p-EGFR and p-MET as well as their downstreat proteins p-ErbB3, p-AKT, and p-ERK. The treatment of HCC827GR cells with DPT induced high ROS generation that led to endoplasmic-reticulum stress. Accordingly, loss of mitochondrial membrane potential and apoptosis by multi-caspase activation were observed. In conclusion, these results demonstrate the apoptotic effects of DPT on HCC827GR cells and signify the potential of DPT to serve as an adjuvant anti-cancer drug by simultaneously inhibiting EGFR and MET.

• BMB Reports
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• 제52권7호
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• pp.439-444
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• 2019

Although hypoxic/ischemic injury is thought to contribute to the incidence of Alzheimer's disease (AD), the molecular mechanism that determines the relationship between hypoxia-induced ${\beta}$-amyloid ($A{\beta}$) generation and development of AD is not yet known. We have now investigated the protective effects of N,4,5-trimethylthiazol-2-amine hydrochloride (KHG26702), a novel thiazole derivative, on oxygen-glucose deprivation (OGD)-reoxygenation (OGD-R)-induced $A{\beta}$ production in SH-SY5Y human neuroblastoma cells. Pretreatment of these cells with KHG26702 significantly attenuated OGD-R-induced production of reactive oxygen species and elevation of levels of malondialdehyde, prostaglandin $E_2$, interleukin 6 and glutathione, as well as superoxide dismutase activity. KHG26702 also reduced OGD-R-induced expression of the apoptotic protein caspase-3, the apoptosis regulator Bcl-2, and the autophagy protein becn-1. Finally, KHG26702 reduced OGD-R-induced $A{\beta}$ production and cleavage of amyloid precursor protein, by inhibiting secretase activity and suppressing the autophagic pathway. Although supporting data from in vivo studies are required, our results indicate that KHG26702 may prevent neuronal cell damage from OGD-R-induced toxicity.

• BMB Reports
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• 제52권2호
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• pp.145-150
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• 2019

Endothelial dysfunction-induced lipid retention is an early feature of atherosclerotic lesion formation. Apoptosis of vascular smooth muscle cells (VSMCs) is one of the major modulating factors of atherogenesis, which accelerates atherosclerosis progression by causing plaque destabilization and rupture. However, the mechanism underlying VSMC apoptosis mediated by endothelial dysfunction in relation to atherosclerosis remains elusive. In this study, we reveal differential expression of several genes related to lipid retention and apoptosis, in conjunction with atherosclerosis, by utilizing a genetic mouse model of endothelial nitric oxide synthase (eNOS) deficiency manifesting endothelial dysfunction. Moreover, eNOS deficiency led to the enhanced susceptibility against pro-apoptotic insult in VSMCs. In particular, the expression of aggrecan, a major proteoglycan, was elevated in aortic tissue of eNOS deficient mice compared to wild type mice, and administration of aggrecan induced apoptosis in VSMCs. This suggests that eNOS deficiency may elevate aggrecan expression, which promotes apoptosis in VSMC, thereby contributing to atherosclerosis progression. These results may facilitate the development of novel approaches for improving the diagnosis or treatment of atherosclerosis.

• Biomolecules & Therapeutics
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• 제27권1호
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• pp.117-125
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• 2019

Mebendazole (MBZ), a microtubule depolymerizing drug commonly used for the treatment of helminthic infections, has recently been noted as a repositioning candidate for angiogenesis inhibition and cancer therapy. However, the definite anti-angiogenic mechanism of MBZ remains unclear. In this study, we explored the inhibitory mechanism of MBZ in endothelial cells (ECs) and developed a novel strategy to improve its anti-angiogenic therapy. Treatment of ECs with MBZ led to inhibition of EC proliferation in a dose-dependent manner in several culture conditions in the presence of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) or FBS, without selectivity of growth factors, although MBZ is known to inhibit VEGF receptor 2 kinase. Furthermore, MBZ inhibited EC migration and tube formation induced by either VEGF or bFGF. However, unexpectedly, treatment of MBZ did not affect FAK and ERK1/2 phosphorylation induced by these factors. Treatment with MBZ induced shrinking of ECs and caused G2-M arrest and apoptosis with an increased Sub-G1 fraction. In addition, increased levels of nuclear fragmentation, p53 expression, and active form of caspase 3 were observed. The marked induction of autophagy by MBZ was also noted. Interestingly, inhibition of autophagy through knocking down of Beclin1 or ATG5/7, or treatment with autophagy inhibitors such as 3-methyladenine and chloroquine resulted in marked enhancement of anti-proliferative and pro-apoptotic effects of MBZ in ECs. Consequently, we suggest that MBZ induces autophagy in ECs and that protective autophagy can be a novel target for enhancing the anti-angiogenic efficacy of MBZ in cancer treatment.

• 한국식품영양학회지
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• 제31권6호
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• pp.865-872
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• 2018

In neuronal cell deaths, oxidative stress is normally implicated with a most of these deaths occurring in neurodegenerative disorders such as the Alzheimer's and Parkinson's diseases. In this study, the neuroprotective effects of Schisandra chinensis (SC) and Ribes fasciculatum (RF) extracts on hydrogen peroxide ($H_2O_2$)-induced oxidative stress in neuroblastic cell line were investigated. For an hour, hydrogen peroxide of $100{\mu}M$ concentration, was induced on neuroblastic cells, causing apoptic cell death. For the neuroprotection, a sample of neuroblastic cells had been pre-treated with SC and RF extracts for 24 hours before application of the hydrogen peroxide. No neurotoxic effects were observed in the cells that had been treated by SC and RF. This prove that the treatment of SC and RF extract prevented apoptotic cell death of neuroblastic cell line exposed to oxidative injury. In addition, applying both SC and RF extracts at a 7:3 ratio increased the neuronal cell survival rate, compared to individual treatments of SC and RF extract. This study suggests that SC and RF extracts may be potential therapeutic agents for the prevention of neuronal cell death.

• 한국동물생명공학회지
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• 제35권4호
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• pp.347-356
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• 2020

Gangliosides are glycolipids in which oligosaccharide is combined with sialic acids. Our previous studies have suggested an interplay between ganglioside GD1a/GT1b and meiotic maturation capacity in porcine oocyte maturation. Furthermore, ganglioside GD1a and GT1b are known for its antioxidant activity, but it is still unclear whether possible antioxidant role of GD1a and GT1b is involved in porcine embryos development competence during in vitro culture (IVC). Here, the effects of ganglioside GD1a and GT1b on the embryonic developmental competence during in vitro culture of porcine were investigated. The effects of ganglioside GD1a and GT1b on the expression of ST3GAL2 were confirmed during embryos development (2-cell, 4-cell, 8-cell and blastocyst) using immunofluorescent staining (IF). As a result, the fluorescent expression of ST3GAl2 was higher in embryos at 4-8 cells stage than blastocysts. Blastocyst development rate significantly increased in only 0.1 μM GD1a and GT1b treated groups compared with control group. To investigate the cellular apoptosis, we analyzed TUNEL assay. In case of only 0.1 μM GD1a and GT1b treated groups, the total number of cells in blastocyst compared with control group, but there was no significant difference in the rate of apoptotic cells. We identified the intracellular ROS levels using DCF-DA staining. According to the result, ROS production significantly decreased in blastocysts derived from the 0.1 μM GD1a and GT1b treated groups. These results suggest that ganglioside GD1a and GT1b improve the developmental competence of porcine embryos via reduction of intracellular ROS during preimplantation stage.

• Journal of Microbiology and Biotechnology
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• 제31권6호
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• pp.775-783
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• 2021

Sea cucumber, Holothuria scabra, is a well-known traditional Asian medicine that has been used for suppressing inflammation, promoting wound healing, and improving immunity. Moreover, previous studies demonstrated that the extract from H. scabra contains many bioactive compounds with potent inhibitory effect on tumor cell survival and progression. However, the effect of the methanolic extract from the body wall of H. scabra (BWMT) on human prostate cancer cells has not yet been investigated. In this study, we aimed to investigate the effects and underlying mechanism of BWMT on prostate cancer cell viability and metastasis. BWMT was obtained by maceration with methanol. The effect of BWMT on cell viability was assessed by MTT and colony formation assays. The intracellular ROS accumulation was evaluated using a DCFH-DA fluorescence probe. Hoechst 33342 staining and Annexin V-FITC/PI staining were used to examine the apoptotic-inducing effect of the extract. A transwell migration assay was performed to determine the anti-metastasis effect. BWMT significantly reduced cell viability and triggered cellular apoptosis by accumulating intracellular ROS resulting in the upregulation of JNK and p38 signaling pathways. In addition, BWMT also inhibited the invasion of PC3 cells by downregulating MMP-2/-9 expression via the ERK pathway. Consequently, our study provides BWMT from H. scabra as a putative therapeutic agent that could be applicable against prostate cancer progression.

• 대한본초학회지
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• 제36권1호
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• pp.1-8
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• 2021

Objective : Citri Unshius Pericarpium (Citrus unshiu peel) has been used in Korean medicine to treat indigestion, vomiting, coughing and phlegm. This study investigated the hepatoprotective effect of ethanol extract of Citrus unshiu peel (CEE) in cadmium (CdCl2)-treated mouse model. Methods : CEE was dissolved in water and administered orally to mice once a day for 7 consecutive days. The mice were then exposed to a single intraperitoneal (i.p.) injection of cadmium (4 mg/kg body weight) to induce acute hepatotoxicity. At the end of the experiment, blood and liver tissue samples were collected, analyzed for alanine aminotransferase (ALT), aspartate aminotransferase (AST), and histopathological evaluation. Liver damage was assessed as the percentage of degenerative areas of the hepatic parenchyma, the number of degenerative hepatocytes, and the number of infiltrated inflammatory cells. Results : In cadmium-treated rats, pretreatment with CEE significantly reduced the serum ALT and AST levels associated with liver damage. Histopathologically, CEE prevented degenerative changes on the hepatic tissues including confluent necrosis, congestions and infiltration of inflammatory cells. CEE also reduced the elevation of oxidative stress markers (nitrotyrosine and 4-hydroxynonenal) and apoptosis markers (cleaved caspase-3 and cleaved PARP) positive cells. PARP protein expression in liver tissue was also restored by CEE. Conclusion : This study showed that CEE exerted antioxidant and anti-apoptotic effects against cadmium-induced liver injury. Thus, it can be concluded that CEE can be used to prevent liver damage caused by cadmium.