• Nutritional Sciences
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• 제6권2호
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• pp.73-77
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• 2003

PAI-1 (plasminogen activator inhibitor-1), leptin, and resistin are synthesized and secreted by Int cells of rodents and have recently been postulated to be an important link to obesity. This study was conducted to identify the nutritional regulation of PAI-1, leptin, and resistin gene expression in 0b/ob mice. The mice were divided into four groups according to nutritional status: control, 48 hour fasting, 48 hour-fasting/12 hour-refeeding, and 48 hour-fasting/24 hour-refeeding. The mRNA levels of each peptide were measured by semi-quantitative RT-PCR. In visceral fat tissue, the level of PAI-1 mRNA increased markedly when 48h-fasted animals were refed with a high carbohydrate-low fat diet. However, lasting/refeeding did not appreciably change PAI-1 mRNA levels in subcutaneous fat tissue. Similar results were obtained for resistin mRNA levels in both types of fat tissues. These findings suggest that visceral adipose tissue might be more sensitively involved in the nutritional regulation of PAI-1 and resistin gene expression compared to subcutaneous fat tissue. The level of leptin mRNA decreased markedly in the 48h-fasted animals, and increased markedly when 48h-fasted animals were refed with a high carbohydrate-low fat diet. The nutritional regulation of leptin mRNA showed similar patterns in both types of fat tissues. In conclusion, the nutritional regulation of gene expression encoding PAI-1, resistin, and leptin from adipocytes may vary according to the type of adipose tissue.

• 한국식품영양학회지
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• 제30권3호
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• pp.531-538
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• 2017

This study was performed to investigate the effects of garlic on uncoupling protein 2 (UCP2) transcriptional regulation of UCP2-luciferase transgenic mice fed on a high fat diet to induce obesity. To examine the transcriptional regulation of UCP2, we generated transgenic mice with a UCP2 promoter (-1,830/+30 bp) containing luciferase as a reporter gene. UCP2-luciferase transgenic mice were fed a 45% high-fat diet for 8 weeks to induce obesity. Subsequently, mice were maintained on either a high-fat control diet (TG-CON), or high-fat diets supplemented with 2% (TG-GL2) or 5% (TG-GL5) garlic for a further 8 weeks. Dietary garlic reduced body weight and energy efficiency ratio in the TG-GL5 group, compared to the TG-CON group. Furthermore, garlic supplementation significantly decreased white adipose tissue fat mass and plasma levels of triglycerides, total cholesterol, and leptin in the TG-GL2 and TG-GL5 groups, compared to the TG-CON group. Specifically, UCP2 promoter activity in metabolic tissues such as liver, white adipose tissue, brown adipose tissue, and skeletal muscle was increased by garlic supplementation. These results suggest that dietary garlic was partially associated with an increase of UCP2 transcriptional activity in metabolic tissues for decreasing obesity.

• Preventive Nutrition and Food Science
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• 제21권4호
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• pp.317-322
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• 2016

Mitochondrial biogenesis is a complex process requiring coordinated expression of nuclear and mitochondrial genomes. The peroxisome proliferator-activated receptor gamma co-activator 1-alpha (PGC-$1{\alpha}$) is a key regulator of mitochondrial biogenesis, and it controls mitochondrial DNA (mtDNA) replication within diverse tissues, including muscle tissue. The aim of this study was to investigate the effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on mtDNA copy number and PGC-$1{\alpha}$ promoter activity in $C_2C_{12}$ muscle cells. mtDNA copy number and mRNA levels of genes related to mitochondrial biogenesis such as PGC-$1{\alpha}$, nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (Tfam) were assayed by quantitative real-time PCR. The PGC-$1{\alpha}$ promoter from -970 to +412 bp was subcloned into the pGL3-basic vector, which includes a luciferase reporter gene. Both EPA and DHA significantly increased mtDNA copy number, dose and time dependently, and up-regulated mRNA levels of PGC-$1{\alpha}$, NRF1, and Tfam. Furthermore, EPA and DHA stimulated PGC-$1{\alpha}$ promoter activity in a dose-dependent manner. These results suggest that EPA and DHA may modulate mitochondrial biogenesis, which was partially associated with increased mtDNA replication and PGC-$1{\alpha}$ gene expression in $C_2C_{12}$ muscle cells.

• Preventive Nutrition and Food Science
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• 제21권3호
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• pp.202-207
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• 2016

The aim of this study was to investigate the association of CD36, a class B scavenger receptor, rs6969989 polymorphism with the serum lipid profiles in Korean women, together with their modulation by oily fish consumption. Subjects were participants from the Korean Genome Epidemiology Study (KoGES), which was initiated in 2001 as a large-scale. A total of 4,210 women aged 39 to 70 were included in this study. Data were collected using self-administered questionnaires, anthropometric measurements, and blood chemical analysis. Dietary intake was analyzed using a semi-quantitative food frequency questionnaire. The minor allele frequency for rs6969989 was found in 12% of this population. Homozygotes minor G allele at the rs6868989 exhibited significantly higher high density lipoprotein cholesterol (HDLC) concentrations (P-trend=0.043) and lower fasting glucose (P-trend=0.013) than major allele A carriers. The risk of low HDL-C was significantly lower in homozygotes for the G allele than the A allele carriers (P-trend=0.032). Gene-diet interaction effects between rs6969989 and oily fish intake were significantly associated with the risk of dyslipidemia (P-interaction=0.004). Subjects with homozygotes minor G allele and high oily fish intake generally had a lower risk of dyslipidemia than did those with major allele homozygotes and low oily fish intake. These findings supported that oily fish consumption may modulate the contributions of CD36 rs6969989 on genetic predisposition to the risk of dyslipidemia.

• Preventive Nutrition and Food Science
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• 제11권3호
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• pp.210-217
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• 2006

This study was performed to investigate effects of the experimental mixture containing soybean peptides, L-carnitine and Garcinia Cambogia extract on body weight and lipid metabolism in rats. Male Sprague-Dawley rats (n=40) of eight weeks old were raised for four weeks with high fat diet (40% fat as calorie) to induce obesity. After induction of obesity, rats were feed control (C) diet, containing either 0.16% (+1D), 1.6% (+10D), 8% (+50D) of experimental mixture for eight weeks. Plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity and total protein and albumin concentration were not different among groups. The Body weight gain was significantly lower in experimental mixture diet group compared to control group. Weights of perirenal fat pad and epididymal fat pad in the +50D group were significantly lower than those in the +1D and +10D groups. Plasma total lipid and liver total cholesterol levels in the experimental groups were significantly lower than those in the control group. Fecal total lipid and total cholesterol excretions were highest in +50D group. These results suggest that the experimental mixture containing peptides, L-carnitine and Garsinia Canbogia extract is effective for reducing the body weight and adipose tissue weight which may be due to the modulation of lipid metabolism and the increased fecal excretion of lipid.

• 한국식품영양학회지
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• 제30권5호
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• pp.900-907
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• 2017

This study was performed to investigate the body fat-lowering effect of garlic powder in peroxisome proliferator-activated receptor ${\gamma}$ coactivator-$1{\alpha}$(PGC-$1{\alpha}$)-luciferase transgenic mice (TG). In this study, we generated transgenic mice with a PGC-$1{\alpha}$ promoter (-970/+412 bp) containing luciferase as a reporter gene. Mice were fed a 45% high-fat diet for 8 weeks to induce obesity. Subsequently, mice were maintained on either a high-fat control diet (CON), or high-fat diets supplemented with 2% (GP2) or 5% (GP5) garlic powder for an additional 8 weeks. Dietary garlic powder reduced the body weight in the GP2 and GP5 groups, compared to the CON group. Furthermore, garlic supplementation significantly decreased the plasma levels of triglycerides, total cholesterol, and leptin in the GP5 group, compared to the CON group. Specifically, luciferase activity in liver, white adipose tissue (WAT), and brown adipose tissue (BAT) was increased by garlic supplementation in a dose-dependent manner. These results suggest that the body fat-lowering effect of garlic powder might be related to PGC-$1{\alpha}$ by the increase in luciferase activity in liver, WAT, and BAT. Furthermore, transgenic mice might be useful for evaluating the body fat-lowering effect of various health functional foods.

• Nutrition Research and Practice
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• 제15권4호
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• pp.528-540
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• 2021

BACKGROUND/OBJECTIVES: In a healthy person, from 35 years of age, there is an annual loss of muscle mass at the rate of 1-2% and is associated with a decline in the quality of life. This study aimed to identify the particular dietary patterns associated with the risk of lower lean muscle mass in Korean postmenopausal women. SUBJECTS/METHODS: The Korea National Health and Nutrition Examination Survey (KNHANES) is a population-based, continuous cross-sectional annual survey. The participants of the KNHANES IV (2008-2009) and V (2010-2011) were considered for this study. The study sample consisted of 1548 postmenopausal women, aged 45-86 years. Lower lean muscle mass was defined as having appendicular skeletal muscle mass corrected for body weight less than 1 standard deviation of the young reference group aged 20 to 39 years in KNHANES IV and V. To identify the dietary pattern using factor analysis, 24-h recall data was used. RESULTS: The prevalence of lower lean muscle mass was 31.3% in this study population. Four dietary patterns were identified by factor analysis; 'Diverse', 'Western', 'Traditional', and 'Snacks and beverages'. The 'Western' pattern, highest factor loadings for flour and bread, potatoes, red meat, processed meat, eggs, and cheese, was significantly associated with a high (60%) risk of lower lean muscle mass (odds ratio [95% confidence interval] = 1.60 [1.07-2.39], P for trend = 0.01) after adjustments for potential covariates. The other 3 dietary patterns were not associated with lower lean muscle mass. CONCLUSIONS: The study findings suggest that the 'Western' dietary pattern that includes flour and bread, potatoes, red meat, processed meat, eggs, and cheese, may be associated with a higher risk of lower lean muscle mass in Korean postmenopausal women.

• Journal of Nutrition and Health
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• 제54권4호
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• pp.335-341
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• 2021

Purpose: Muscle mitochondria play a key role in regulating fatty acid and glucose metabolism. Dysfunction of muscle mitochondria is associated with metabolic diseases such as obesity and type 2 diabetes. Isorhamnetin (ISOR), also known as 3-O-methylquercetin, a quercetin metabolite, is a naturally occurring flavonoid in many plants. This study evaluated the effects of ISOR on the regulation of the mitochondrial function of C2C12 muscle cells. Methods: C2C12 muscle cells were differentiated for 5 days, and then treated in various concentrations of ISOR. Cytotoxicity was determined by assessing cell viability using the water-soluble tetrazolium salt-8 assay principle at different concentrations of ISOR and time points. Levels of the mitochondrial DNA (mtDNA) content and gene expression were measured by quantitative real-time polymerase chain reaction. The citrate synthase (CS) activity was quantified by the enzymatic method. Results: ISOR at a concentration of 10 µM did not show any cytotoxic effects. ISOR increased the mtDNA copy number in a time- or dose-dependent manner. The messenger RNA levels of genes involved in mitochondrial function, such as peroxisome proliferator-activated receptor-γ coactivator-1α, and uncoupling protein 3 were significantly stimulated by the ISOR treatment. The CS activity was also significantly increased in a time- or dose-dependent manner. Conclusion: These results suggest that ISOR enhances the regulation of mitochondrial function, which was at least partially mediated via the stimulation of the mtDNA replication, mitochondrial gene expression, and CS activity in C2C12 muscle cells. Therefore, ISOR may be useful as a potential food ingredient to prevent metabolic diseases-associated muscle mitochondrial dysfunction.

• 대한지역사회영양학회지
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• 제17권5호
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• pp.664-675
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• 2012

This study was conducted to investigate the cross-sectional associations between dietary factors and the risk of metabolic syndrome (MetS) in 12,755 subjects (males 5,146, females 7,609) aged 19 years or above using data from the 4th (2007-2009) Korea National Health and Nutrition Examination Survey (KNHANES). The prevalence of MetS in Korean adults was 23.6% (males 26.1%, females 20.9%) with the criteria for modified National Cholesterol Education Program Adult Treatment Panel III. While males had a higher prevalence of abdominal obesity, hyperglycemia, hypertriglyceridemia, and high blood pressure than females, the prevalence of low HDL-cholesterol level was higher in females than in males. Among dietary guidelines, the response of 'yes' for asking practice of 'avoiding salty foods', and 'eating moderately and increasing physical activity for healthy weight' were significantly associated with the decreased risk of MetS in both males and in females. Especially, the risk of MetS was significantly lower in the subjects that responded the practice of all items of Korean Dietary Guidelines. Significantly negative associations with MetS were also found in the responding for practice of 'limiting consumption of alcoholic beverages' in males, and taking dietary supplements in females. Skipping breakfast was positively associated with the risk of MetS. In conclusion, dietary behaviors such as having breakfast, practice of dietary guidelines, and food consumption in moderation could modify the prevalence of MetS, and our findings could be useful for establishing guidelines for preventing MetS.

• 한국식품과학회지
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• 제47권5호
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• pp.574-578
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• 2015

본 연구의 목적은 닭고기의 저장 기간 동안 천연 첨가물에 의한 병원성 미생물 생장 억제 효과를 조사하기 위함이다. 닭고기 저장기간 동안 천연 첨가물에 의한 병원성 미생물 억제 효과를 조사하기 위하여 닭고기의 껍질 표면에 천연 첨가물을 단독 혹은 배합하여 처리하였다. 병원성 미생물은 닭고기 냉장 저장기간중에 위생과 안전성에 영향을 미치는 부패세균인 S. Typhimurium 및 P. aeruginosa를 사용하였다. 천연첨가물은 키토산, EGCG, 마늘을 각각 2% 농도로 시료 표면에 처리한 다음 $4^{\circ}C$ 냉장 조건하에서 12일 동안 6일 간격으로 2번에 걸쳐 병원성 미생물 억제효과를 관찰하였다. 각각의 병원성 미생물의 생장 억제 효과는 키토산, EGCG 및 마늘을 단독 혹은 두 가지 배합 처리한 것보다 세 가지 배합 처리한 것이 처리 시간별로 훨씬 더 높은 미생물 억제 효과를 나타내었다. 이 결과들은 키토산, EGCG와 마늘을 포함하는 세 가지 배합된 천연첨가물이 닭고기의 저장 동안 병원성 세균 생장 억제를 위한 천연첨가제로 유용하게 사용될 수 있음을 시사하고 있다. 아울러 본 연구 결과들은 천연첨가물을 이용한 유해 미생물 제어 기술 개발을 위한 기초 자료로 사용될 수 있을 것으로 기대된다.