• 한국식품영양과학회지
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• 제43권8호
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• pp.1166-1173
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• 2014

본 연구는 굴 가수분해물이 아세트아미노펜에 의한 간독성의 무독화 효과를 HepG-2 세포를 사용하여 조사하였다. 굴 가수분해물은 굴 단백질의 가교연결을 위해 TGase로 전처리하거나(TGPN) 혹은 하지 않고(PN), 1% Protamex와 1% Neutrase 단백질 분해효소로 2단 가수분해하였다. 두 종류의 굴 가수분해물은 아세트아미노펜으로 간 손상을 유도한 세포에 각각 처리하여 세포 생존율을 측정하였으며, 세포 배양 시 배양액으로 유출된 GOT와 GPT 활성을 측정하였다. TGPN 가수분해물의 경우 아세트아미노펜만을 처리한 negative 대조군($60.7{\pm}3.2%$)에 비하여 $100{\mu}g/mL$와 $200{\mu}g/mL$의 농도에서 각각 $136.2{\pm}1.4%$와 $179.6{\pm}3.8%$의 높은 세포 생존율을 보였다. PN 가수분해물은 $100{\mu}g/mL$와 $200{\mu}g/mL$의 농도에서 각각 $107.9{\pm}8.8%$와 $130.6{\pm}7.6%$의 세포 생존율을 보였다. GOT 활성은 negative 대조군의 경우에 $38.3{\pm}0.2$ Karmen/mL이었으며, TGPN($200{\mu}g/mL$)과 PN($200{\mu}g/mL$)에서는 $19.9{\pm}0.5$와 $22.0{\pm}2.4$ Karmen/mL로 농도에 따라 유의적인 활성 감소를 확인할 수 있었다. 그리고 GPT 활성도 GOT와 같은 경향의 활성을 나타내었다. 이 같은 결과에 미루어 굴 유래 가수분해물의 간 보호 건강 기능 식품 혹은 약물 개발의 가능성을 확인하였으며 앞으로 가수분해 펩티드 중의 유효성분에 대한 구조동정과 작용 기전에 관한 연구가 필요할 것으로 보인다.

• Applied Biological Chemistry
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• 제42권3호
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• pp.229-234
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• 1999

사람 간세포 유래의 배양 세포인 HepG2 세포의 지질 합성과 분비에 미치는 linoleic acid(LA, 18 : 2 n-6) 및 우혈청알부민 (bovine serum albumin: BSA) 첨가 농도의 영향에 대하여 검토하였다. 간세포는 DMEM배지(기본 배지)에 0.2 mM LA을 첨가한 배지 및 LA와 BSA(0.2-1.0%)를 첨가한 배지(LA+BSA 배지)에서 배양하였다. 각 지질의 동위원소 표적에는 $[^{14}C]acetate$를 이용하여 6시간 배양후의 지질합성과 분비를 측정하였다. 그 결과, 기본 배지중에 LA의 첨가는 콜레스테롤의 $[^{14}C]acetate$ 표적량을 저하 시켰다. 한편, LA배지에 BSA의 첨가에 의해, 총 콜레스테롤의 $[^{14}C]acetate$ 표적량은 증가하는 경향을 나타내었다. LA+BSA 배지에서 간세포의 총 콜레스테롤 변동은 유리형 콜레스테롤에의 표적량 증가에 기인하는 것으로 나타났다. LA배지에 BSA를 첨가 하였을때 콜레스테롤 분비가 증가 하였는데, 이는 지질의 분비과정에 BSA가 관여하는 것을 시사하는 것이다. 간세포내 총 지질에의 $[^{14}C]acetate$ 표적량은 각 군간의 유의치는 인정되지 않았다. 그러나, LA 배지에의 BSA 첨가는 $[^{14}C]acetate$표식 지방산의 중성지질 획분에의 표적량은 증가하고, 인지질 획분에 표적량은 감소하여, 양지질의 합성에는 상반되는 결과를 나타내었다. $[^{14}C]acetate$ 표적 중성지질, 인지질 및 유리지방산의 분비는 LA배지에 비교해 LA+BSA 배지에서 현저하게 증가하였다. 이상의 결과에서, 사람 간배양 세포에서 LA와 BSA는 각각 지질대사에 다른 영향을 미치고, BSA 농도는 리포단백질 분비에 영향을 미치는 것으로 시사된다.

• Archives of Pharmacal Research
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• 제29권5호
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• pp.405-411
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• 2006

Biphenyl dimethyl dicarboxylate (DDB) is a hepatoprotectant, which is used as an adjuvant agent in a treatment for chronic hepatitis. Amantadine is an antiviral agent, which is utilized primarily in the treatment of influenza, but also, occasionally in the treatment of hepatitis C. In a previous study, we reported that DDB, coupled with amantadine, would exert an anti-HBV effect, via the induction of interferon-inducible gene expression in the HepG2 2.2.15 cell line. The primary objective of the present study was to determine whether or not DDB and/or amantadine exhibit anti-HBV properties, and what mechanisms of action might be involved in such properties. In our study, we were able to determine that DDB stimulates Jak/Stat signaling, and induces the expression of interferon alpha $(IFN-\alpha)$ stimulated genes, most notably 6-16 and ISG12. In addition, the antiviral effectors induced by $IFN-\alpha$, PKR, OAS, and MxA, were regulated in the presence of DDB at its optimal concentration $(250{\mu}g/mL)$, to a degree commensurate with the degree of induction associated with the $IFN-\alpha$ treated group. Finally, we determined that the replication of pregenomic RNA and HBeAg was inhibited by DDB treatment, and this inhibition was maximized when coupled with the administration of amantadine $(25{\mu}g/mL)$. In conclusion, the results of this study demonstrated clearly that DDB, as well as the combination of DDB/amantadine, directly inhibited $IFN-\alpha$ signaling-mediated replication of HBV in infected hepatocytes, and thus may represent a novel treatment for chronic hepatitis B, which would be characterized principally by its improved safety over other treatment strategies.

• 한국콘텐츠학회논문지
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• 제21권11호
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• pp.518-527
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• 2021

본 연구에서는 황색 방울토마토의 생리활성 식품소재로서의 가능성을 알아보기 위하여 추출 건조물의 폴리페놀 및 플라보노이드 함량, 항산화 효과 및 암세포에 대한 생육억제 효과를 검증하였다. 폴리페놀 및 플라보노이드 함량은 각각 10.96±1.57 및 4.12±0.41 mg/g이었다. 항산화 활성은 DPPH 및 ABTS 라디칼 소거능을 측정하여 확인하였고 free radical을 50% 감소시키는 농도인 RC50은 각각 490.83±17.35 ㎍/mL과 355.90±0.79 ㎍/mL이었다. 추출 건조물은 정상 간세포(Chang)에 대해서는 세포 독성을 보이지 않았고 A549 폐암세포에 대해서는 생육 억제 활성을 나타내지 않았으나 자궁경부암세포(HeLa)와 간암세포(HepG2)에 대해서는 100 ㎍/mL 농도로 처리하였을 때 각각 15.2% 및 18.4%의 생육 억제 효과를 보였다. 본 연구의 결과로부터 황색 방울토마토의 항산화 활성과 자궁경부암세포와 간암세포 등 일부 암세포에 대한 억제 활성이 검증되어 생리활성 식품소재로서 가능성을 확인하였다.

• Biomolecules & Therapeutics
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• 제26권6호
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• pp.599-607
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• 2018

Fasiglifam (TAK-875) a G-protein coupled receptor 40 (GPR40) agonist, significantly improves hyperglycemia without hypoglycemia and weight gain, the major side effects of conventional anti-diabetics. Unfortunately, during multi-center Phase 3 clinical trials, unexpected liver toxicity resulted in premature termination of its development. Here, we investigated whether TAK-875 directly inflicts toxicity on hepatocytes and explored its underlying mechanism of toxicity. TAK-875 decreased viability of 2D and 3D cultures of HepG2, a human hepatocarcinoma cell line, in concentration-(>$50{\mu}M$) and time-dependent manners, both of which corresponded with ROS generation. An antioxidant, N-acetylcysteine, attenuated TAK-875-mediated hepatotoxicity, which confirmed the role of ROS generation. Of note, knockdown of GPR40 using siRNA abolished the hepatotoxicity of TAK-875 and attenuated ROS generation. In contrast, TAK-875 induced no cytotoxicity in fibroblasts up to $500{\mu}M$. Supporting the hepatotoxic potential of TAK-875, exposure to TAK-875 resulted in increased mortality of zebrafish larvae at$25{\mu}M$. Histopathological examination of zebrafish exposed to TAK-875 revealed severe hepatotoxicity as manifested by degenerated hypertrophic hepatocytes with cytoplasmic vacuolation and acentric nuclei, confirming that TAK-875 may induce direct hepatotoxicity and that ROS generation may be involved in a GPR40-dependent manner.

• 대한한의학방제학회지
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• 제29권4호
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• pp.167-179
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• 2021

Objectives : Oxidative stress is a important cause of liver disease, and regulation of oxidative stress is essential to maintain the normal metabolic function of the liver. Until a recent date, there has been no studies on the hepatoprotective effect of Ikwiseungyang-tang (IWSYT). Therefore, this study aims to demonstrate the hepatoprotective effect of IWSYT and its related molecular mechanisms on arachidonic acid (AA) + iron induced oxidative stress model in HepG2 cells. Methods : To determine the cytoprotective effect of IWSYT against AA + iron-induced oxidative stress, cell viability, apoptosis-related proteins, intracellular reactive oxygen species (ROS), GSH, and mitochondrial membrane potential (MMP) were measured. Nuclear factor erythroid 2-related factor 2 (Nrf2) activation was analyzed by immunoblot analysis. In addition, Nrf2 transcription activation through ARE binding was measured by reporter gene assays, and the expression of the Nrf2 target antioxidant genes were confirmed by immunoblot analysis. Results : IWSYT increased cell viability from cell death induced by AA + Iron, and inhibited apoptosis by regulating apoptosis-related proteins. Furthermore, IWSYT protected cells by inhibiting intracellular ROS production, GSH depletion, and MMP degradation. Nrf2 activation was increased by IWSYT, and Nrf2 target genes were activated by IWSYT too. Conclusions : These results suggest that IWSYT can protect hepatocytes from oxidative stress through Nrf2 activation and can be potentially applied in the prevention and treatment of liver damage.

• 동의생리병리학회지
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• 제27권6호
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• pp.764-770
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• 2013

Stevia rebaudiana is a traditional herb used as a sweetener in Brazil and Paraguay as well as Korea and China. This study investigated the efficacy of Stevia rebaudiana methanol extract (SRE) to protect cells against the mitochondrial dysfunction and apoptosis in hepatocyte. To determine the effects of SRE on oxidative stress, we used the human derived hepatocyte cell line, HepG2 cell. Treatment of arachidonic acid (AA)+iron in HepG2 cells synergistically amplified cytotoxicity, as indicated by the excess reactive oxygen species (ROS) and mitochondrial permeability transition by fluorescence activated cell sorter (FACS) and immunoblot analysis. Treatment with SRE protected hepatocytes from AA+iron-induced cellular toxicity, as shown by alterations in the protein levels related with cell viability such as procaspase-3. SRE also prevented the mitochondrial dysfunction induced by AA+iron, and showed anti-oxidant effects as inhibition of $H_2O_2$ production and GSH depletion. Moreover, we measured the effects of SRE on AMP-activated protein kinase (AMPK), a key regulator in determining cell survival or death. Acetyl-CoA Carboxylase (ACC), a direct downstream target of AMPK. SRE increased phosphorylation of ACC, and prevented the inhibition of ACC phosphorylation by AA+iron. These results indicated that SRE has the ability to protect cells against AA+iron-induced $H_2O_2$ production and mitochondrial impairment, which may be mediated with AMPK-ACC pathway.

• BMB Reports
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• 제54권9호
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• pp.476-481
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• 2021

Liver receptor homolog-1 (LRH-1) has emerged as a regulator of hepatic glucose, bile acid, and mitochondrial metabolism. However, the functional mechanism underlying the effect of LRH-1 on lipid mobilization has not been addressed. This study investigated the regulatory function of LRH-1 in lipid metabolism in maintaining a normal liver physiological state during fasting. The Lrh-1^f/f and LRH-1 liver-specific knockout (Lrh-1^LKO) mice were either fed or fasted for 24 h, and the liver and serum were isolated. The livers were used for qPCR, western blot, and histological analysis. Primary hepatocytes were isolated for immunocytochemistry assessments of lipids. During fasting, the Lrh-1^LKO mice showed increased accumulation of triglycerides in the liver compared to that in Lrh-1^f/f mice. Interestingly, in the Lrh-1^LKO liver, decreases in perilipin 5 (PLIN5) expression and genes involved in β-oxidation were observed. In addition, the LRH-1 agonist dialauroylphosphatidylcholine also enhanced PLIN5 expression in human cultured HepG2 cells. To identify new target genes of LRH-1, these findings directed us to analyze the Plin5 promoter sequence, which revealed -1620/-1614 to be a putative binding site for LRH-1. This was confirmed by promoter activity and chromatin immunoprecipitation assays. Additionally, fasted Lrh-1^f/f primary hepatocytes showed increased co-localization of PLIN5 in lipid droplets (LDs) compared to that in fasted Lrh-1^LKO primary hepatocytes. Overall, these findings suggest that PLIN5 might be a novel target of LRH-1 to mobilize LDs, protect the liver from lipid overload, and manage the cellular needs during fasting.

• Nutrition Research and Practice
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• 제12권2호
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• pp.110-117
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• 2018

BACKGROUND/OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver disease and is closely associated with metabolic syndrome. In the present study, we observed the effect of ethanol extract of Allium fistulosum (EAF) on NAFLD and have suggested the possibility of using EAF as a natural product for application in the development of a treatment for NAFLD. MATERIALS/METHODS: The preventive effect on hepatic lipid accumulation was estimated by using an oleic acid (OA)-induced NAFLD model in vitro and a Western diet (high-fat high-sucrose; WD)-induced obese mouse model. Animals were divided into three groups (n = 7): normal diet group (ND), WD group, and WD plus 1% EAF group. RESULTS: EAF reduced OA-stimulated lipid accumulation in HepG2 cells in the absence of cellular cytotoxicity and significantly blocked transcriptional activation of sterol regulatory element-binding protein 1 and fatty acid synthase genes. Subsequently, we investigated these effects in vivo in mice fed either ND or WD in the presence or absence of EAF supplementation. In comparison to the ND controls, the WD-fed mice exhibited increases in body weight, liver weight, epididymal fat weight, and accumulation of fat in hepatocytes, and these effects were significantly attenuated by EAF supplementation. CONCLUSIONS: Allium fistulosum attenuates the development of NAFLD, and EAF elicits anti-lipogenic activity in liver. Therefore, EAF represents a promising candidate for use in the development of novel therapeutic drugs or drug combinations for the prevention and treatment of NAFLD.

• Journal of Ginseng Research
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• 제42권4호
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• pp.419-428
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• 2018

Background: Despite the large number of studies on ginseng, pharmacological activities of ginseng seed oil (GSO) have not been established. GSO is rich in unsaturated fatty acids, mostly oleic and linoleic acids. Unsaturated fatty acids are known to exert a therapeutic effect in nonalcoholic fatty liver disease (NAFLD). In this study, we investigated the protective effect and underlying mechanisms of GSO against NAFLD using in vitro and in vivo models. Methods: In vitro lipid accumulation was induced by free fatty acid mixture in HepG2 cells and by 3 wk of high fat diet (HFD)-feeding in Sprague-Dawley rats prior to hepatocyte isolation. The effects of GSO against diet-induced hepatic steatosis were further examined in C57BL/6J mice fed a HFD for 12 wk. Results: Oil Red O staining and intracellular triglyceride levels showed marked accumulation of lipid droplets in both HepG2 cells and rat hepatocytes, and these were attenuated by GSO treatment. In HFD-fed mice, GSO improved HFD-induced dyslipidemia and hepatic insulin resistance. Increased hepatic lipid contents were observed in HFD-fed mice and it was lowered in GSO (500 mg/kg)-treated mice by 26.4% which was evident in histological analysis. Pathway analysis of hepatic global gene expression indicated that GSO increased the expression of genes associated with ${\beta}$-oxidation (Ppara, Ppargc1a, Sirt1, and Cpt1a) and decreased the expression of lipogenic genes (Srebf1 and Mlxipl), and these were confirmed with reverse transcription and quantitative polymerase-chain reaction. Conclusion: These findings suggest that GSO has a beneficial effect on NAFLD through the suppression of lipogenesis and stimulation of fatty acid degradation pathway.