• Journal of Life Science
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• v.29 no.9
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• pp.964-971
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• 2019

Hepatic lipid accumulation and insulin resistance increases in patients with non-alcoholic fatty liver disease. Piperine is a major compound found in black pepper (Piper nigrum) and long pepper (P. longum). Piperine has been used in fine chemical for its anti-cancer, anti-obesity, anti-diabetic, anti-inflammatory and anti-oxidant properties. However, the signaling-based mechanism of piperine and its role as an inhibitor of lipogenesis and insulin resistance in human hepatocyte cells remains ill-defined. In the present study, we explored the effects of piperine on lipid accumulation and insulin resistance, and explored the potential underlying molecular mechanisms in palmitate-treated HepG2 cells. Piperine treatment resulted in a significant reduction of triglyceride content. Furthermore, piperine treatment decreased palmitate-treated intracellular lipid deposition by inhibiting the lipogenic target genes, sterol-regulatory-element-binding protein 1c (SREBP-1c) and fatty acid synthase (FAS); whereas the expression of carnitine palmitoyl transferase (CPT-1) and phosphorylation of acetyl coenzyme A carboxylase (ACC) gene involved in fatty acid oxidation was increased. Moreover, piperine also inhibited the phosphorylation of insulin receptor substrate (IRS)-1 (Ser307). Piperine treatment modulated palmitate-treated lipid accumulation and insulin resistance in HepG2 cells with concomitant reduction of lipogenic target genes, such as SREBP-1 and FAS, and induction of CPT-1-ACC and phosphorylation of IRS-1 (Tyr632)-Akt pathways. Therefore, piperine represents a promising treatment for the prevention of lipid accumulation and insulin resistance.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.3
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• pp.236-245
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• 2016

Because microalgae represent high growth rate than terrestrial plants, and it can accumulate significant lipid and carbohydrate content, and other bioactive compounds such as carotenoid and polyphenol in their body, it has been considered as one of the promising resources in bio-energy, and other industries. Although many studies has been performed about the microalgae-derived biochemical accumulation under various abiotic conditions such as different temperatures, salinities and light intensities, the studies about simultaneous effect of those parameters has rarely been performed. Therefore, this study focused on evaluation of simultaneous effect of different salinity (10, 30, 50 psu) and temperatures (20, 25, $30^{\circ}C$) on the changes of biomass, lipid, starch and photosynthetic pigment accumulation. As results, the highest growth rate was achieved at $30^{\circ}C$ and 30 psu in the both algal cultures, and the photosynthetic pigment, chlorophyll a and total carotenoid content, were increased in a temperature-dependent manner. The accumulation of lipid and starch contents exhibited different aspects under different combinations of temperature and salinity. From the results, it is suggested that the changes of microalgal lipid and starch accumulation under different salinities may be affected by the different temperatures.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.4
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• pp.586-590
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• 2003

The pharmacological effect of Korean-Chinese traditional herbal medicine, Hawangyeonhaedoktang (HT) on experimentally induced-triglyceride accumulation in cultured human hepatocyte HepG2 cells was studied. HePG2 cells were cultured in the Dulbecco's modified Eagle's (DME) medium without (Control medium) or with HT (0.5 mg/mL and 5.0 mg/mL) containing 1 mM oleate, 0.2% bovine serum albumin (BSA), and glucose 4.5 mg/mL for 6 and 24 hours in experiment I and 2 mM oleate, 0.5% BSA, and glucose 4.5 mg/mL for 6, 24 and in hours in Experiment II or 1 and 3 hours in Experiment III. Oleate ［$^{14}$ C］(0.5 $\mu$Ci/mL medium) added as a radioactive lipid precursor in the experiment I. In the experiment I, the intracellular triglyceride concentration was decreased remarkably during incubation for 6 and 24 hours, in a dose-dependent manner. At the same time, HT caused a decrease in the incorporation of ［$^{14}$ C］ oleate into intracellular triglyceride fraction and the secretion of triglyceride labeled with ［$^{14}$ C］ oleate into medium. In the experiment II and III compared to experiment I, the triglyceride accumulation in HepG2 cells was occurred, and HT prevented the accumulation of triglyceride during incubation for 24 and 48 hours. This result suggest that HT prevent the triglyceride accumulation in human hepatocytes by its inhibiting action on the intercellular triglyceride biosynthesis.

• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.362-366
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• 2012

This study was performed to promote the effective utilization of edible marine resources and to develop functional food material from edible marine resource extracts for inhibiting lipid accumulation in liver. Edible marine resource extracts (ME) were prepared by hot water (MWE) and 80% ethanolic (MEE), and both the MWE and MEE extracts were assessed as to their cell cytotoxicity, and Oil Red O staining. Results demonstrated that ME showed no cytotoxic effects. However, treatment with MEE in the concentration of 1000, 500, and 250 ${\mu}g/mL$ significantly inhibited the lipid accumulation in HepG2 cells compared to MWE. Especially, among the 80% ethanolic extracts, Pagrus major, Larimichthys polyactis, Clupea pallasii, Octopus minor, Enteroctopus dofleini, Styela clava, dried sea mustard, and Enteromorpha intestinalis showed greater lipid accumulation inhibitory activity than the others.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.1-8
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• 2018

The objective of this study was to compare the antihyperlipidemic effects of different Dendropanax morbifera leaf extracts in vitro. The extracts differed in terms of specimen age, harvesting season, and extraction method. RAW 264.7 cells were pretreated with these extracts and stimulated by oxidized low-density lipoprotein. Ethanol was used to induce toxicity in HepG2 cells. Cellular lipid accumulation was quantified using oil red O staining in both these cells. The extracts were evaluated for their inhibitory effects on 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. RAW 264.7 cells treated with the 60% ethanol extract of an 8-year-old specimen harvested in November exhibited the lowest lipid accumulation. The 30% ethanol extract of a 5-year-old specimen harvested in May exhibited the greatest protection from ethanol-induced cytotoxicity in HepG2 cells. The hot water extract of an 8-year-old specimen harvested in May showed the greatest inhibition of HMG-CoA reductase. These results showed that D. morbifera extracts prepared from leaves that are harvested in May possess the highest antihyperlipidemic effects.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.498-504
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• 2014

Allium senescens L. is perennial plant of the Liliaceae family that grows throughout Korea. In this study, we investigated the effect of Allium senescens L. methanol extracts on reactive oxygen species (ROS) production and lipid accumulation during adipogenesis. Our results indicated that 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity of Allium senescens L. methanol extracts increased in a dose-dependent manner. Allium senescens L. methanol extracts suppressed ROS production and lipid accumulation during adipogenesis. In addition, Allium senescens L. methanol extracts inhibited the mRNA expression of the pro-oxidant enzyme, such as G6PDH and lead to a reduction in the mRNA levels of the transcription factors, such as sterol regulatory element binding proteins 1c, peroxisome proliferator-activated receptor ${\gamma}$, and CCAAT/enhancer-binding proteins ${\alpha}$. These results indicate that Allium senescens L. methanol extracts inhibit adipogenesis by modulating ROS production associated with ROS-regulating genes and directly down-regulating adipogenic transcription factors.

• The Korean Journal of Malacology
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• v.14 no.2
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• pp.113-120
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• 1998

참굴에 다환성방향족탄화수소(PAHs)의 축적성과 이 물질들이 미치는 독성을 평가하기 위해 해양환경에서 빈번히 검출되는 PAHs 중의 하나인 anthracene을 사용한 모델연구를 수행하였다. Anthracene을 0.01-1ppm의 농도로 2주간 참굴에 노출시켰을 때 참굴 조직내의 anthracene의 농도는 노출기간 및 노출강도에 비례하여 최고 25-85배까지 증가하였다. 소화맹낭과 폐각근의 지질 과산화물가는 노출기간 및 노출농도에 관련하여 현저히 증가하였으나 수용성단백질, glycogen, nucleoside/nucleotide 및 핵산의 함량은 변화하지 않았다. 이 결과로 anthracene은 굴의 조직내로 원할하게 축적됨을 확인하였으며 과산화지질의 함량은 anthracene에의 오염에 대한 예민한 생화학적 지표가 될 수 있을 것으로 사료된다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.605-607
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• 2006

한국지질자원연구원은 1990년대 초반부터 순차적으로 강원도 경주, 양산, 삼척, 홍성, 정선, 지리산 등 6 개 지역에 GPS위성들이 발사하는 자료를 연속적으로 수신하여 자동관리할 수 있는 GPS 상시관측소를 설치하고 GPS위성자료를 축적해 왔다. 이에 한국지질자원연구원은 축적된 자료 중 2005년과 2006년에 걸친 자료를 이용하여 정밀좌표를 계산하였다. 자료처리에는 스위스 Bern대학이 개발한 Bernese4.0을 이용하였다. 이렇게 계산된 위 6 개 GPS상시관측소의 정밀 좌표를 이용함으로써 GPS위성자료를 사용하는 하는 지구과학 분야 및 측량 분야의 발전에 기여할 것이다.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.2
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• pp.149-156
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• 2022

Lipid accumulation product (LAP) is a new index reflecting central lipid accumulation and is known to be a strong independent indicator for identifying the risk of cardiovascular disease (CVD) or diabetes mellitus (DM). This study was conducted to assess the relationship between the homeostasis model assessment of insulin resistance (HOMA-IR) and LAP according to the presence or absence of obesity in Korean adults. The study was carried out using data from the 2019 Korean National Health and Nutrition Examination Survey (KNHANES) and included 6,090 adults aged 20 years or older. There were several key findings. First, after adjusting for related variables, the mean of the HOMA-IR levels (M±SE, 95% confidence interval) was positively associated with the quartiles of LAP in the overall population (P<0.001), non-obese (P<0.001) or obese groups (P<0.001). Second, in all the groups (overall population, non-obese and obese groups), the mean value of the fasting blood glucose (all, P<0.001), insulin (all, P<0.001), and the metabolic syndrome score (all, P<0.001) increased with the increasing quartiles of LAP. Insulin resistance was thus positively associated with an increase in the LAP in Korean adults with or without obesity.

• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.355-357
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• 2007