• The Korean Journal of Food And Nutrition
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• v.26 no.1
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• pp.8-14
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• 2013

This study was performed to investigate the effects of ethanolic extract of Ulmus davidiana root (UE) on lipid metabolism in mice fed a high-fat diet (HF) for 7 weeks. Forty male ICR mice were randomly divided into four groups; normal diet group (N), high-fat diet group (HF), HF with 0.5% UE (HF-L) and 1% UE (HF-H) group. Body weight, body weight gain, and liver weight in the HF group was significantly higher than in the N group, while those of the HF-L and HF-H group were unchanged. UE improved HF-induced dyslipidemia by reducing serum triglyceride, total cholesterol, and the atherogenic index. There was no difference in serum HDL-cholesterol among experimental groups. However, the HDL-cholesterol/total cholesterol ratio was significantly increased in the HF-L and HF-H group. Histological analysis showed that HF-fed mice developed hepatocellular microvesicular vacuolation as a result of fat accumulation. These changes were attenuated by 1% UE supplementation. In addition, hepatic triglyceride and cholesterol levels in the HF-H group significantly reduced. Taken together, these results demonstrated that lipid levels in the blood and liver were reduced by UE, suggesting that it might be beneficial for the prevention and treatment of hyperlipidemia and fatty liver.

• Molecules and Cells
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• v.41 no.2
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• pp.140-149
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• 2018

The $TIS21^{/BTG2/PC3}$ gene belongs to the antiproliferative gene (APRO) family and exhibits tumor suppressive activity. However, here we report that TIS21 controls lipid metabolism, rather than cell proliferation, under fasting condition. Using microarray analysis, whole gene expression changes were investigated in liver of TIS21 knockout (TIS21-KO) mice after 20 h fasting and compared with wild type (WT). Peroxisome proliferator-activated receptor alpha ($PPAR{\alpha}$) target gene expression was almost absent in contrast to increased lipid synthesis in the TIS21-KO mice compared to WT mice. Immunohistochemistry with hematoxylin and eosin staining revealed that lipid deposition was focal in the TIS21-KO liver as opposed to the diffuse and homogeneous pattern in the WT liver after 24 h starvation. In addition, cathepsin E expression was over 10 times higher in the TIS21-KO liver than that in the WT, as opposed to the significant reduction of thioltransferase in both adult and fetal livers. At present, we cannot account for the role of cathepsin E. However, downregulation of glutaredoxin 2 thioltransferase expression might affect hypoxic damage in the TIS21-KO liver. We suggest that the $TIS21^{/BTG2}$ gene might be essential to maintain energy metabolism and reducing power in the liver under fasting condition.

• BMB Reports
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• v.54 no.9
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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.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.1
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• pp.127-134
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• 2015

Castration induces the accumulation of body fat and deposition of intramuscular fat in Korean cattle, resulting in improved beef quality. However, little is known about the metabolic adaptations in the liver following castration. To understand changes in lipid metabolism following castration, hepatic expression levels of lipid metabolism genes were compared between Korean bulls and steers. Steers had higher (p<0.001) hepatic lipids contents and higher (p<0.01) mRNA levels of lipogenic acetyl-CoA carboxylase. This differential gene expression may, in part, contribute to increased hepatic lipid content following the castration of bulls. However, we found no differences in the hepatic expression levels of genes related to triglyceride synthesis (mitochondrial glycerol-3-phosphate acyltransferase, diacylglycerol O-acyltransferase 1 and 2) and fatty acid (FA) oxidation (carnitine palmitoyltransferase 1A, C-4 to C-12 straight chain acyl-CoA dehydrogenase, very long chain acyl-CoA dehydrogenase) between bulls and steers. No differences in gene expression for very-low-density lipoprotein (VLDL) secretion, including apolipoprotein B mRNA and microsomal triglyceride transfer protein (MTTP) protein, were observed in the liver although MTTP mRNA levels were higher in steers compared to bulls. In conclusion, FA synthesis may contribute to increased hepatic lipid deposition in steers following castration. However, hepatic lipid metabolism, including triglyceride synthesis, FA oxidation, and VLDL secretion, was not significantly altered by castration. Our results suggest that hepatic lipid metabolism does not significantly contribute to increased body fat deposition in steers following castration.

• Journal of Life Science
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• v.26 no.2
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• pp.155-163
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• 2016

Metabolism of lactate dehydrogenase (EC 1.1.1.27, LDH) was studied to identify the function of LDH-C. Tissues of LDH liver-specific Ldh-C expressed Carassius auratus and eye-specific Ldh-C expressed Lepomis macrochirus after starvation were studied. LDH activity in liver tissue from C. auratus was increased after starvation. And LDH specific activity (units/mg) and LDH/CS were increased in tissues. It means the anaerobic metabolism was taking place in C. auratus after starvation. LDH B₄ isozyme was decreased in skeletal muscle and increased in heart tissue. LDH C₄ isozymes those showed in eye and brain tissues were identified as liver-specific C₄ isozymes and disappeared after starvation. And C hybrid in eye, A₄ isozyme in brain, and both C hybrid and C₄ isozyme in liver tissue were increased, respectively. In L. macrochirus, the level of variation of LDH activities was low but greatly increased especially in eye tissue and LDH A₄ and AC hybrid were increased in brain tissue. The LDH activities in tissues from C. auratus and L. macrochirus remained 30.30-18.64% and 25-18.75%, respectively, as a result of the inhibition by 10 mM of pyruvate. The Km^PYR values of LDH in C. auratus were increased. As a result, LDH liver-specific C₄ isozyme was expressed in liver, brain and eye tissues during starvation. It seems metabolism of lactate was predominant in brain tissue. After starvation, the liver-specific LDH-C was affected more than eye-specific LDH-C.

• Environmental Mutagens and Carcinogens
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• v.21 no.1
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• pp.30-33
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• 2001

Salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, SAL), a dopaminergic isoquinoline neurotoxin, has been implicated to contribute the etiology of Parkinson's disease and neuropathology of chronic alcoholism. In our previous results, SAL was reported to have the mutagenicity and clastogenicity not in bacteria but in mammalian cells, and its genotoxic potential was known to be potentiated in the presence of rat liver S-9 fraction. This may indicate that some metabolite(s) of SAL was involved in the mutagenic potentials. To investigate the SAL metabolites, the metabolism studies of SAL were conducted in vitro rat liver S-9 fraction and in vivo using rats by high performance liquid chromatography and gas chromatography/mass spectrometry. The methylated metabolite of SAL was found in urine of rats, while the same methylating form of metabolite was not produced from the in vitro metabolism system using rat liver S-9 fraction.

• Journal of Nutrition and Health
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• v.34 no.4
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• pp.375-383
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• 2001

This study was performed to investigate the effects of dried powder and juice of Aster scaber on lipid metabolism and antioxidative capacity in rats. Twenty one male Sprague-Dawley rats weighing 170.9$\pm$15.1g were blocked into 3 groups according to body weight and raised for 4 weeks with diets containing 5%(w/w) dried powder and juice from the same amount of Aster scaber. Food intake, body weight gain, food efficiency ratio and organ weights were not different among all the experimental groups. On lipid metabolism, both dried powder and juice supplementation decreased plasma total lipid, triglyceride(TG), total cholesterol and liver cholesterol levels by increasing fecal lipid excretions. Plasma thiobarbituric acid reactive substance(TBARS) concentrations were significantly decreased in dried powder and juice groups, whereas liver TBARS concentrations were not affected by experimental diets. Red blood cell(RBC) superoxide dismutase(SOD) activities were significantly increased by dried powder and juice supplementation, while activities of other antioxidative enzymes in RBC and liver were decreased or showed no changes. In conclusion, both Aster scaber dried powder and juice had the effects on lowering lipid levels by increasing fecal lipid excretions, and inhibiting of plasma lipid peroxidation in animals and the effects of juice were higher than that of dried powder. (Korean J Nutrition 34(4) : 375-383, 2001)

• Journal of Nutrition and Health
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• v.31 no.1
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• pp.5-12
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• 1998

This study was designed to examine how dietary protein levels affect organ growth and protein metabolism in early and normally weaned rats. Early and normally weaned rats separated fro the dam on the 15th and 121st day postpartum, respectively. were fed diets containing three levels of protein : low(10%) , normal (20%),and high(40%) . On the 35th day, the weight and DNA, RNA and protein contents in brain , liver, and kidney were determined to ascertain organ and cellular growth. Furthermore, serum total protein , albumin , $\alpha$-amino N and creatine and urinary urea N, and creatinine were determined in order to ascertain protein metabolism and renal functions. Dietary protein levels were not observed to significantly affect total DNA content, which may represent an index of cell number in the liver, brain and kidney. Fresh weight and protein/DNA ratio, which may represent indices of cell size, significantly increased in proportion to dietary protein in the kidney. As for the early weaned rats , the liver cell size significantly decreased. Dietary protein levels and weaning periods did not affect serum total protein and albumin . However, serum urea-N significantly increased in proportion to dietary protein levels whereas serum $\alpha$-amino N was decreased by early weaning . Nitrogen retention was lower in early weaned rats fed low or high levels of protein than in normally weaned rats. The results demonstrate that low or high levels of dietary protein have less desirable effects on protein metabolism in prematurely weaned rats.

• Journal of Nutrition and Health
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• v.30 no.3
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• pp.229-243
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• 1997

This study was performed to investigate the effects of dietary fibers from tangerine peels on lipid and cadmium metabolism. And effects were compared with those of commercial dietary fibers($\alpha$-cellulose, citrus pectin). Sixty male rats of Sprague-Dawley strain weighing 186.7$\pm$2.6g were blocked into 12 groups according to body weight, and were raised for 2 weeks. Cadmium chloride was given at the levels of 0 of 400 ppm in diet. Various dietary fibers were given at the level of 0 or 4%(w/w) of diet. The results are summarized as follow. In lipid metabolism, insoluble fibers[insoluble dietary fibers from tangerine peels(IDE), $\alpha$-celluolse] increased fecal excretion of lipids by inhcreasing feces weight, and decreased the concentrations of serum triglyceride and liver lipids. Soluble dietary fibers from tangerine peels(SDF) decreased the concentrations of serum cholesterol and liver lipids by increasing fecal lipids, too. In cadmium metabolism, soluble fivers(SDF, pectin) inhibited Cd absorption by increasing fecal Cd excretion and decreased Cd concentrations of intestion, liver and kidney. In conclusion, among the extracted fibers, SDF were more effective on lipid and Cd lowering activity and IDF had effect of increasing fecal lipid excretion. This result is useful to reduce food waste and utilize waste products.

• YAKHAK HOEJI
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• v.40 no.1
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• pp.78-83
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• 1996

An ethanol administration causes hepatic triglyceride accumulation in rats. To assess whether the herbal extract containing Phaseoli radiati semen(herbal extract) inhibit s the triglyceride accumulation in the liver, we determined the hepatic triglyceiide levels in rats fed ethanol and the herbal extract. In addition, the blood ethanol concentrations and the activities of hepatic alcohol dehydrogenase(ADH) and aldehyde dehydrogenase(ALDH) were measured to determine the effects of the herbal extract on alcohol metabolism in rats. The administration of the herbal extract markedly reduced the triglyceride levels elevated by ethanol in the liver as well as in the serum. The herbal extract remarkably lowered blood ethanol concentrations in a dose-dependent manner. The ADH activities decreased by ethanol were recovered to the normal level by the herbal extract treatment. Moreover, the ALDH activities slightly decreased by ethanol increased beyond the normal level by the herbal extract treatment. We conclude that the herbal extract inhibits the hepatic triglyceride accumulation and stimulates alcohol metabolism by preventing ADH and ALDH from inhbition by the ethanol administration in the rat liver.