• Biomolecules & Therapeutics
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• v.20 no.5
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• pp.492-498
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• 2012

Phytochemicals have been known to exhibit potent antioxidant activity. This study examined cytoprotective effects of phytochemicals including quercetin, catechin, caffeic acid, and phytic acid against oxidative damage in SK-Hep-1 cells induced by the oxidative and non-oxidative metabolism of ethanol. Exposure of the cells to excess ethanol resulted in a significant increase in cytotoxicity, reactive oxygen species (ROS) production, lipid hydroperoxide (LPO), and antioxidant enzyme activity. Excess ethanol also caused a reduction in mitochondrial membrane potential (MMP) and the quantity of reduced glutathione (GSH). Co-treatment of cells with ethanol and quercetin, catechin, caffeic acid and phytic acid significantly inhibited oxidative ethanol metabolism-induced cytotoxicity by blocking ROS production. When the cells were treated with ethanol after pretreatment of 4-methylpyrazole (4-MP), increased cytotoxicity, ROS production, antioxidant enzyme activity, and loss of MMP were observed. The addition of quercetin, catechin, caffeic acid and phytic acid to these cells showed suppression of non-oxidative ethanol metabolism-induced cytotoxicity, similar to oxidative ethanol metabolism. These results suggest that quercetin, catechin, caffeic acid and phytic acid have protective effects against ethanol metabolism-induced oxidative insult in SK-Hep-1 cells by blocking ROS production and elevating antioxidant potentials.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.66-67
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• 2003

It is well known that osteoblasts and osteoc1asts playa key role in bone metabolism. They involve in osteoformation or bone destruction which are ragulated by various factors such as thyroid hormone, parathyroid hormone, estrogen, growth factor and cytokine. Recently, it is demonstrated that oxidative stress is one of pathological factors in bone metabolism, but it is left unknown about mechanism between oxidative stress and bone metabolism.(omitted)

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.1
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• pp.98-105
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• 2010

A total of 16 crossbred post-weaning pigs (10.64${\pm}$0.27 kg BW) were individually penned and assigned to one of two treatments to investigate the influences of diquat-induced oxidative stress on performance and arginine metabolism. Pigs in the oxidative stress group were injected intra-peritoneally with 10 mg/kg BW of diquat, while the control group were injected with isotonic saline. All pigs were fed ad libitum. The experiment lasted for 7 days. The results indicated that compared with control treatment, oxidative stress induced by diquat significantly decreased average daily gain, intake and feed conversion. The treatment decreased activities of antioxidant enzymes, increased concentration of malondialdehyde in plasma, increased cationic amino acid transporter-1 mRNA level and activity of ornithine aminotransferase and concentrations of arginine and citrulline in the jejunum, decreased the concentrations of arginine in plasma and kidney, and decreased induced nitric oxide synthase mRNA level. It is concluded that oxidative stress induced by diquat can influence absorption and metabolism of arginine and consequently modify the requirement of arginine for post-weaning pigs.

• Biotechnology and Bioprocess Engineering:BBE
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• v.3 no.2
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• pp.109-111
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• 1998

The effect of dissolved oxygen concentration on the metabolism of glucose in Pseudomonas putida BM014 was investigated. Glucose was completely converted to 2-ketogluconate via extracellular oxidative pathway and then taken up for cell growth under the condition of sufficient dissolved oxygen concentration. On the other hand, oxygen limitation below dissolved oxygen tension (DOT) value of 20% of air saturation caused the shift of glucose metabolism from the extracellular oxidative pathway to the intracellular phosphorylative pathway. Specific activities of hexokinase and gluconate kinase in intracellular phosphorylation pathway decreased as the DOT increased, while 2-ketogluconokinase activity in extracellular oxidative pathway increased under the same condition. This result can be usefully applied to microbial transformation of glucose to 2-ketogluconate, the synthetic precursor for iso-vitamine C, with almost 100% yield via extracellular oxidation by simple DOT control.

• Biomolecules & Therapeutics
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• v.26 no.1
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• pp.39-44
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• 2018

In 1923, Dr. Warburg had observed that tumors acidified the Ringer solution when 13 mM glucose was added, which was identified as being due to lactate. When glucose is the only source of nutrient, it can serve for both biosynthesis and energy production. However, a series of studies revealed that the cancer cell consumes glucose for biosynthesis through fermentation, not for energy supply, under physiological conditions. Recently, a new observation was made that there is a metabolic symbiosis in which glycolytic and oxidative tumor cells mutually regulate their energy metabolism. Hypoxic cancer cells use glucose for glycolytic metabolism and release lactate which is used by oxygenated cancer cells. This study challenged the Warburg effect, because Warburg claimed that fermentation by irreversible damaging of mitochondria is a fundamental cause of cancer. However, recent studies revealed that mitochondria in cancer cell show active function of oxidative phosphorylation although TCA cycle is stalled. It was also shown that blocking cytosolic NADH production by aldehyde dehydrogenase inhibition, combined with oxidative phosphorylation inhibition, resulted in up to 80% decrease of ATP production, which resulted in a significant regression of tumor growth in the NSCLC model. This suggests a new theory that NADH production in the cytosol plays a key role of ATP production through the mitochondrial electron transport chain in cancer cells, while NADH production is mostly occupied inside mitochondria in normal cells.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.12
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• pp.1889-1896
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• 2019

Objective: This study aimed to investigate the effects of prepartum body condition score (BCS) on the milk yield, lipid metabolism, and oxidative status of Holstein cows. Methods: A total of 112 multiparous Holstein cows were divided into 4 groups according to the BCS at 21 days before calving: medium BCS (3.0 to 3.25, MBCS), high BCS (3.5 to 3.75, HBCS), higher BCS (4.0 to 4.25, HerBCS), and highest BCS (4.5 to 5.0, HestBCS). Blood samples were collected on 21, 14, and 7 days before calving (precalving), on the calving day (calving), and on 7, 14, and 21 days after calving (postcalving). The indices of lipid metabolism and oxidative status were analyzed using bovine-specific enzyme-linked immunosorbent assay kit. Colostrum were taken after calving and analyzed by a refractometer and milk analyzer. The individual milk yield was recorded every 3 days. Results: The density and levels of immune globulin and lactoprotein of colostrum from Holstein cows in the HestBCS group were the highest (p<0.05). These animals not only had the highest (p<0.05) levels of serum non-esterified fatty acids and beta-hydroxybutyrate, but also had the highest (p<0.05) levels of malondialdehyde, superoxide dismutase, catalase, vitamin A, and vitamin E. In addition, greater (p<0.05) BCS loss was observed in the HestBCS cows. Conclusion: This study demonstrates that the milk yield, lipid metabolism, and oxidative status of Holstein cows are related to prepartum BCS and BCS loss during the transition period. HestBCS cows are more sensitive to oxidative stress and suffer greater loss of BCS after calving, whereas the MBCS animals had better milk yield performance.

• Journal of Ginseng Research
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• v.43 no.3
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• pp.475-481
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• 2019

Background: The ginsenoside Rg1 has been shown to exert various pharmacological activities with health benefits. Previously, we have reported that Rg1 promoted myogenic differentiation and myotube growth in C2C12 myoblasts. In this study, the in vivo effect of Rg1 on fiber-type composition and oxidative metabolism in skeletal muscle was examined. Methods: To examine the effect of Rg1 on skeletal muscle, 3-month-old mice were treated with Rg1 for 5 weeks. To assess muscle strength, grip strength tests were performed, and the lower hind limb muscles were harvested, followed by various detailed analysis, such as histological staining, immunoblotting, immunostaining, and real-time quantitative reverse transcription polymerase chain reaction. In addition, to verify the in vivo data, primary myoblasts isolated from mice were treated with Rg1, and the Rg1 effect on myotube growth was examined by immunoblotting and immunostaining analysis. Results: Rg1 treatment increased the expression of myosin heavy chain isoforms characteristic for both oxidative and glycolytic muscle fibers; increased myofiber sizes were accompanied by enhanced muscle strength. Rg1 treatment also enhanced oxidative muscle metabolism with elevated oxidative phosphorylation proteins. Furthermore, Rg1-treated muscles exhibited increased levels of anabolic S6 kinase signaling. Conclusion: Rg1 improves muscle functionality via enhancing muscle gene expression and oxidative muscle metabolism in mice.

• Toxicological Research
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• v.30 no.4
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• pp.235-242
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• 2014

Cancer cells are known to drastically alter cellular energy metabolism. The Warburg effect has been known for over 80 years as pertaining cancer-specific aerobic glycolysis. As underlying molecular mechanisms are elucidated so that cancer cells alter the cellular energy metabolism for their advantage, the significance of the modulation of metabolic profiles is gaining attention. Now, metabolic reprogramming is becoming an emerging hallmark of cancer. Therapeutic agents that target cancer energy metabolism are under intensive investigation, but these investigations are mostly focused on the cytosolic glycolytic processes. Although mitochondrial oxidative phosphorylation is an integral part of cellular energy metabolism, until recently, it has been regarded as an auxiliary to cytosolic glycolytic processes in cancer energy metabolism. In this review, we will discuss the importance of mitochondrial respiration in the metabolic reprogramming of cancer, in addition to discussing the justification for using mitochondrial DNA somatic mutation as metabolic determinants for cancer sensitivity in glucose limitation.

• Journal of Korean Traditional Oncology
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• v.20 no.1
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• pp.81-88
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• 2015

Generally, normal cells synthesize adenosine triphosphate (ATP) through oxidative phosphorylation in the mitochondria. However, they produce ATP through lactic acid fermentation on hypoxic condition. Interestingly, many cancer cells rely on aerobic glycolysis for ATP generation instead of mitochondrial oxidative phosphorylation, which is termed as "Warburg effect". According to results from recent researches on differences of cancer cell metabolism from normal cell metabolism and because chemotherapy to suppress rapidly growing cells, as a side effect of cancer treatment, can still target healthy cells, there is merit in the development of small-molecule inhibitors targeting metabolic enzymes such as pyruvate dehydrogenase kinase (PDHK), lactate dehydrogenase (LDH) and monocarboxylate transporter (MCT). For new anticancer therapy, in this review, we show recent advances in study on cancer cell metabolism and molecules targeting metabolic enzymes which are importantly associated with cancer metabolism for cancer therapy. Furthermore, we would also like to emphasize the necessity of development of molecules targeting metabolic enzymes using herbal medicines and their constituents for anticancer drugs.

• Nutrition Research and Practice
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• v.10 no.4
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• pp.386-392
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• 2016

BACKGROUND/OBJECTIVES: Changes in nutritional status during gestation and lactation have detrimental effects on offspring metabolism. Several animal studies have shown that maternal high-fat diet (HFD) can predispose the offspring to development of obesity and metabolic diseases, however the mechanisms underlying these transgenerational effects are poorly understood. Therefore, we examined the effect of maternal HFD consumption on metabolic phenotype and hepatic expression of involved genes in dams to determine whether any of these parameters were associated with the metabolic outcomes in the offspring. MATERIALS/METHODS: Female C57BL/6 mice were fed a low-fat diet (LFD: 10% calories from fat) or a high-fat diet (HFD: 45% calories from fat) for three weeks before mating, and during pregnancy and lactation. Dams and their male offspring were studied at weaning. RESULTS: Dams fed an HFD had significantly higher body and adipose tissue weights and higher serum triglyceride and cholesterol levels than dams fed an LFD. Hepatic lipid levels and mRNA levels of genes involved in lipid metabolism, including $LXR{\alpha}$, SREBP-2, FXR, LDLR, and ABCG8 were significantly changed by maternal HFD intake. Significantly lower total liver DNA and protein contents were observed in dams fed an HFD, implicating the disturbed liver adaptation in the pregnancy-related metabolic demand. HFD feeding also induced significant oxidative stress in serum and liver of dams. Offspring of dams fed an HFD had significantly higher serum cholesterol levels, which were negatively correlated with liver weights of dams and positively correlated with hepatic lipid peroxide levels in dams. CONCLUSIONS: Maternal HFD consumption induced metabolic dysfunction, including altered liver growth and oxidative stress in dams, which may contribute to the disturbed cholesterol homeostasis in the early life of male mice offspring.