• Nutritional Sciences
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• 제8권3호
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• pp.175-180
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• 2005

Green tea, which has high polyphenols amount, is thought to have hypocholesterolemic effects. The present study was performed to further examine the hypocholesterolemic action of green tea, especially (-) epigallocatechin gallate (EGCG) for its effect on diet-induced hypercholesterolemia in rats. Male Sprague-Dawley rats (n=15) were fed a green tea-free diet (control), $1.0\%$ green tea catechin (catechin) or $0.5\%$ green tea catechin EGCG for seven weeks. Hypercholesterolemia was induced by adding $1\%$ cholesterol and $0.5\%$ cholic acid to all diets. There was no difference in food intake and body weight gain among the groups. The green tea EGCG treatment led to a significant improvement in plasma levels of total cholesterol, low density lipoprotein (LDL)-cholesterol and high density lipoprotein (HDL)/LDL ratio (p<0.05). There was no significant effect on the plasma HDL-cholesterol level. The catechin treatment led to a 4.19-fold increase in the LDL-receptor mRNA level compared to the control, but the EGCG treatment did not affect the hepatic LDL-receptor mRNA level. Our results suggest that when blood cholesterol level is down-regulated by green tea EGCG, the LDL receptor gene-independent pathway may dominate the hypocholesterolemic action of EGCG.

• 약학회지
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• 제56권6호
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• pp.364-365
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• 2012

Liver is the major organ to regulate the systemic glucose homeostasis and insulin resistance. Excess energy intake leads to triglyceride accumulation in adipose tissue first and subsequent accumulation in liver, resulting in obesity and type 2 diabetes. The representative pathological animal model for obesity associated insulin resistance is a high fat diet (HFD) fed mice model. Given the essential role of liver fat accumulation in developing systemic insulin resistance in obesity, I measured the liver triglyceride contents in HFD fed mice as a function of time. As such, in this report, I show the cause and effect relationship with regard to time during a HFD feeding between a variety of factors that are related to systemic insulin resistance including glucose intolerance, plasma insulin level and inflammatory gene expression in liver and adipose tissue.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.142-142
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• 1998

This study has been undertaken to examine the effect of biphenyl dimethyl dicarboxylate (DDB) on rat liver drug metabolizing enzyme in order to understand the mechanism of DDB on improving hepatic toxicity in rat liver. After DDB was administered into male rats for different periods of time, mRNA level of CYP1A1 and CYP2B1 was measured by polymerase chain reaction (PCR). DDB treatment resulted in increase in CYP2B1 mRNA level whereas there was no change in CYP1A1 mRNA level. This effect of DDB was time dependent reaching maximal level by 2-day treatment. DDB dose response study showed that 50mg/kg DDB induced CYP2B1 mRNA to maximal level and DDB icreased CYP2B1 gene expression with dose-dependent manner. Based on studies of lipid peroxidation, serum ALT and AST levels and histopathologic examination showed DDB protection on CCl4 induced hepatotoxiccity.

• The Korean Journal of Physiology and Pharmacology
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• 제17권6호
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• pp.525-530
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• 2013

Multidrug resistance 3 (MDR3) is expressed on the canalicular membrane of the hepatocytes and plays an important role in protecting the liver from bile acids. Altered ABCB4 gene expression can lead to a rare hepatic disease, low phospholipid-associated cholelithiasis (LPAC). In this study, we characterized 3 ABCB4 mutations in LPAC patients using various in vitro assay systems. We first measured the ability of each mutant to transport paclitaxel and then the mechanisms by which these mutations might change MDR3 transport activity were determined using immunoblotting, cell surface protein biotinylation, and immunofluorescence. Through a membrane vesicular transport assay, we observed that the uptake of paclitaxel was significantly reduced in membrane vesicles expressing 2 ABCB4 mutations, F165I and S320F. Both mutants showed significantly decreased total and cell surface MDR3 expression. These data suggest two missense mutations of ABCB4 may alter function of MDR3 and ultimately can be determined as LPAC-causing mutations.

• 대한한방내과학회지
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• 제25권1호
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• pp.59-70
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• 2004

Objectives : Previous studies showed that treatment with Chungganhaeju-tang prevents hepatic inflammation and apoptosis in alcoholic liver disease. The purpose of our study is to determine if any relations exsists between the transcription factor $NF{\kappa}B$, an orchestrating expression of a large number of genes and inhibitory effects of Chungganhaeju-tang on ethanol induced apoptosis. Materials and Methods : To assess the role of $NF{\kappa}B$, we blocked NFkB activation by delivering to the kupffer cells $I{\kappa}B{\Delta}N$, a dominant negative $NF{\kappa}B$ inhibitor, and investigated if Chungganhaeju-tang still prevented apoptosis. Results : When $NF{\kappa}B$ activation was blocked, there was no inhibitory effect of Chungganhaeju-tang on ethanol induced apoptosis of kupffer cells. Conclusion : This result suggests that Chungganhaeju-tang protects the liver from ethanol induced apoptosis by activating the $NF{\kappa}B$ that plays a key role in porotecting mechanism and reducing inflammatory cytokine gene expression.

• Asian-Australasian Journal of Animal Sciences
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• 제21권1호
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• pp.19-24
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• 2008

The purpose of this study was to detect expression of genes related to egg production in Taiwan Country chickens by suppression subtractive hybridization. Liver samples of mRNA extraction from two Taiwan Country chicken strains (L2 and B), originated from the same population but with very distinct egg production rates after long-term selection for egg and meat production respectively. Two-way subtraction was performed. The hepatic cDNA from the low egg production chickens (B) was subtracted from the hepatic cDNA from the high egg production strain (L2). The reversed subtraction (L2 from B) was also performed. The resulting differentially expressed gene fragments were cloned and sequenced. We sequenced 288 clones from the forward subtraction and 96 clones from the reverse subtraction. These genes were subjected to further screening to confirm the differential expression between the two genetic breeds of chickens. The apolipoprotein B (apoB) was expressed to a greater extent in the liver of the L2 than in the B line chickens. The 5-aminoimidazole- 4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (PURH) was expressed to a greater extent in the liver of the B than in the L2 strain chickens. We demonstrated that both apoB and PURH were more highly expressed in the liver than that in other tissues (muscle, ovary, and oviduct) in laying Taiwan Country chickens. Taken together, these data suggest that after the selection for egg production, expression of apoB and PURH genes were also changed. Whether the changed expression of these genes is directly related to egg production is not known, but these two genes may be useful markers for egg laying performance in Taiwan Country chickens.

• Journal of Ginseng Research
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• 제20권3호
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• pp.241-247
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• 1996

The effects of ginseng total saponin, ginsenoside-Rb, and -Rb, on the reduction of chmlesterol level and the myNA expression rates of HMG CoA reductase and LDL receptor in Hep G2 were investigated and compared with that of lovastatin, a competitive HMG CoA reductase Inhibitor. The amounts of cholesterol in Hep G2 decreased in total saponin-and ginsenoside-treated groups as compared with that of control group, while there was no significant reduction in lovastatin-treated group. The mRNA expression rates of HMG CoA reductase increased in total saponin and gin- senoside groups except for ginsenoside-Rb, (10-3%) group and decreased in lovastatin group com- pared with that of control group. The mRNA expression rates of LDL receptor generally increased In all of the test groups except for total saponin (10-5%) group compared with that of control group. Because the ginseng components tested were more effective in the reduction of cholesterol level in Hep G2 than lovastatin and induced the gene expression of LDL receptor, we suggest the possibility that they could be used as a replacement agent for lovastatin which can not be prescribed especially to patients with hepatic diseases.

• BMB Reports
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• 제57권6호
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• pp.287-292
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• 2024

Hepatocellular Carcinoma (HCC), the predominant primary hepatic malignancy, is the prime contributor to mortality. Despite the availability of multiple surgical interventions, patient outcomes remain suboptimal. Immunotherapies have emerged as effective strategies for HCC treatment with multiple clinical advantages. However, their curative efficacy is not always satisfactory, limited by the dysfunctional T cell status. Thus, there is a pressing need to discover novel potential biomarkers indicative of T cell exhaustion (Tex) for personalized immunotherapies. One promising target is Cyclin-dependent kinase inhibitor 2 (CDKN2) gene, a key cell cycle regulator with aberrant expression in HCC. However, its specific involvement remains unclear. Herein, we assessed the potential of CDKN2 expression as a promising biomarker for HCC progression, particularly for exhausted T cells. Our transcriptome analysis of CDKN2 in HCC revealed its significant role involving in HCC development. Remarkably, single-cell transcriptomic analysis revealed a notable correlation between CDKN2 expression, particularly CDKN2A, and Tex markers, which was further validated by a human cohort study using human HCC tissue microarray, highlighting CDKN2 expression as a potential biomarker for Tex within the intricate landscape of HCC progression. These findings provide novel perspectives that hold promise for addressing the unmet therapeutic need within HCC treatment.

• Journal of Microbiology and Biotechnology
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• 제34권2호
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• pp.425-435
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• 2024

Schisandra chinensis extract (SCE) protects against hypocholesterolemia by inhibiting proprotein convertase subtilisin/kexin 9 (PCSK9) protein stabilization. We hypothesized that the hypocholesterolemic activity of SCE can be attributable to upregulation of the PCSK9 inhibition-associated low-density lipoprotein receptor (LDLR). Male mice were fed a low-fat diet or a Western diet (WD) containing SCE at 1% for 12 weeks. WD increased final body weight and blood LDL cholesterol levels as well as alanine transaminase and aspartate aminotransferase expression. However, SCE supplementation significantly attenuated the increase in blood markers caused by WD. SCE also attenuated WD-mediated increases in hepatic LDLR protein expression in the obese mice. In addition, SCE increased LDLR protein expression and attenuated cellular PCSK9 levels in HepG2 cells supplemented with delipidated serum (DLPS). Non-toxic concentrations of schisandrin A (SA), one of the active components of SCE, significantly increased LDLR expression and tended to decrease PCSK9 protein levels in DLPS-treated HepG2 cells. High levels of SA-mediated PCSK9 attenuation was not attributable to reduced PCSK9 gene expression, but was associated with free PCSK9 protein degradation in this cell model. Our findings show that PCSK9 secretion can be significantly reduced by SA treatment, contributing to reductions in free cholesterol levels.

• 한국발생생물학회지:발생과생식
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• 제10권2호
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• pp.97-103
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• 2006

Vg은 난생 척추동물의 성숙한 암컷 혈청에 존재하는 성 특이 단백질로서 $E_2$에 의해 합성이 유도된다. 본 연구는 뱀장어 Vg과 ER 유전자 발현에 대한 androgen과 성장호르몬(GH)의 영향을 조사하였다. 미성숙 뱀장어($200{\sim}250g$)에 $E_2(5{\sim}5,000\;{\mu}g/kg\;bw)$, 뱀장어 recombinant GH(eGH, $1{\sim}10\;{\mu}g/kg$) 또는 methyltestosterone(MT, $1{\sim}5\;mg/kg$)를 각각 단독 또는 eGH 또는 MT와 혼합하여 주사한 후 10일 후에 샘플을 채취하였다. 간 ER과 Vg mRNA는 RT-PCR을 이용하여 분석하였다. $E_2$에 의해 발현된 Vg 유전자는 농도 의존적으로 증가하였다. $E_2(500\;{\mu}g/kg)+MT(5mg/kg)$ 또는 $E_2(500\;{\mu}g/kg)+eGH(10\;{\mu}g/kg)$의 처리는 각각 $E_2$ 단독처리에 비해 높은 Vg mRNA의 발현을 유도하였다. eGH($10\;{\mu}g/kg$) 또는 MT(5mg/kg) 단독 처리는 Vg mRNA 발현을 유도하지 못했다. 한편 ER mRNA의 발현은 호르몬 처리에 관계없이 관찰되었다. Vg mRNA와 마찬가지로 ER mRNA의 발현도 $E_2(5{\sim}500\;{\mu}g/kg\;bw)$ 처리에 의해 농도 의존적으로 증가하는 경향이 있었으나 통계적 유의차는 없었다. $E_2(500\;{\mu}g/kg)$와 MT(5mg/kg) 또는 eGH($10\;{\mu}g/kg$)의 혼합투여 또한 $E_2$에 의해 유도된 ER mRNA 발현을 증가시키지 못했다. 결론적으로 Vg 유전자 발현에 있어서 $E_2$는 없어서는 안 되는 필수요소이지만 $E_2$ 자체만으로는 충분한 Vg 유전자를 발현하지 못하고 GH 또는 웅성호르몬 등의 도움이 필요하다. 또한 MT 또는 GH는 ER 유전자 발현에 영향을 미치지 못하며 다른 경로를 통해 Vg 유전자 발현에 관여하는 것으로 생각된다.