• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.8
• /
• pp.1328-1336
• /
• 2003

This study was done to investigate the effects of n-3, n-6 fatty acid and d-limonene on the hepatic membrane lipid composition, protein kinase C (PKC) and glutathione S-transferase (GST) activities in experimental rat hepatocarcinogenesis. Sprague-Dawley female rats were fed with two different types of dietary oil for 20 weeks. Corn oil (CO) and sardine oil (SO) were used at 15% by weight as a source of n-6 and n-3 fatty acid, respectively. One week after feeding, rats were intraperitoneally injected twice with a dose of diethylnitrosamine (DEN, 50 mg/kg body weight) and after 1 week 0.05% phenobarbital (PB) was provided with drinking water. Membrane fractional lipid composition showed that the content of cholesterol was higher in 50 group than CO group and also significantly decreased by d-limonene. The content of phospholipid was increased by carcinogen treatment but not affected by dietary oils or d-limonene. Membrane C/PL molar ratio was significantly decreased by d-limonene or carcinogen treatment in 50 groups but not in CO groups. Fatty acid composition was changed by dietary oils but not by carcinogen treatment or d-limonene. Cytosolic PKC activity was not significantly different by dietary oils, d-limonene or carcinogen treatment. However, membrane PKC activity was significantly increased by carcinogen treatment and decreased by d-limonene. Cytosolic GST activity was affected by d-limonene or carcinogen treatment in all dietary groups. These data indicate that dietary oils, d-limonene and carcinogen treatment can not change much membrane phospholipid composition. But membrane C/PL molar ratio was changed by carcinogen treatment and d -limonene although the effect was different between dietary oils. Therefore, it is suggested that different dietary oils and d-limonene can somewhat modulate the changes of membrane fluidity and activities of membrane bound enzymes like membrane associated PKC during carcinogenesis.

• Journal of the Korean Magnetic Resonance Society
• /
• v.12 no.1
• /
• pp.1-13
• /
• 2008

Acetyl-CoA carboxylase (ACC) catalyzes the first step in fatty acid biosynthesis: the synthesis of malonyl-CoA from acetyl-CoA. As essential regulators of fatty acid biosynthesis and metabolism, ACCs are regarded as therapeutic targets for the treatment of metabolic diseases such as obesity, In ACC, the biotinoyl domain performs a critical function by transferring an activated carboxyl group from the biotin carboxylase domain to the carboxyl transferase domain, followed by carboxyl transfer to malonyl-CoA. Despite the intensive research on this enzyme, only the bacterial and yeast ACC structures are currently available, To explore the mechanism of ACC holoenzyme function, we determined the structure of the biotinoyl domain of human ACC2 and analyze its characteristics using NMR spectroscopy. The 3D structure of the hACC2 biotinoyl domain has a similar folding topology to the previously determined domains from E. coli and P. Shermanii, however, the 'thumb' structure is absent in the hACC2 biotinoyl domain. Observations of the NMR signals upon the biotinylation indicate that the biotin group of hACC2 does not affect the structure of the biotinoyl domain, while the biotin group for E. coli ACC interacts directly with the thumb residues that are not present in the hACC2 structure. These results imply that, in the E. coli ACC reaction, the biotin moiety carrying the carboxyl group from BC to CT can pause at the thumb of the BCCP domain. The human biotinoyl domain, however, lacks the thumb structure and does not have additional non-covalent interactions with the biotin moiety; thus, the flexible motion of the biotinylated lysine residue must underlie the "swinging arm" motion. This study provides insight into the mechanism of ACC holoenzyme function and supports the "swinging arm" model in human ACCs.

• Nutrition Research and Practice
• /
• v.7 no.3
• /
• pp.153-159
• /
• 2013

We investigated whether the combination of phytochemicals and acetic acid in the form of fruit vinegar provides an additive effect on changes of mRNA levels related to fatty acid oxidation in human hepatocyte (HepG2). Among the seven fruit vinegars (Rubuscoreanus, Opuntia, blueberry, cherry, red ginseng, mulberry, and pomegranate) studied, treatment of HepG2 with pomegranate vinegar (PV) at concentrations containing 1 mM acetic acid showed the highest in vitro potentiating effect on the mRNA expression levels of peroxisome proliferator-activated receptor ${\alpha}$, carnitinepalmitoyl transferase-1, and acyl-CoA oxidase compared to the control group (P < 0.05). Reversed-phase liquid chromatography in combination with quadrupole time-of-flight mass spectrometry analysis revealed four potential compounds (punicalagin B, ellagic acid, and two unidentified compounds) responsible for altered gene expression in HepG2 cells treated with PV as compared with the others. Further investigations are warranted to determine if drinking PV beverages may help to maintain a healthy body weight in overweight subjects.

• Natural Product Sciences
• /
• v.15 no.3
• /
• pp.156-161
• /
• 2009

Rubus coreanus, commonly known as 'red raspberry' is used as a traditional oriental medicine in Korea for the management of diseases such as impotence, spermatorrhea and athsma, and for allergies, in combination with other herbal preparations, in many centuries. We undertook a comparison of the hepatoprotective effect of ethanol extracts of the unripe (UREx) and ripe (RREx) R. coreanus extract against acetaminophen (AAP) induced hepatotoxicity in rats. UREx reduced the elevated alanine aminotransferase (ALP), aspartate aminotransferase (AST), total bilirubin (TB), alkaline phosphatase (AP), lipid peroxide and nitric oxide content which had been increased by AAP administration. UREx also increased the cellular glutathione (GSH) content and induced the glutathione-S-transferase (GST), glutathione peroxidase (GSH-Px) content which had been decreased by AAP. RREx did not exhibit strong hepatoprotective effect or antioxidant activity under the same conditions. The experimental results show that the degree of the ripening of R. coreanus affects the hepatoprotective activity in the AAP-intoxicated rats. These findings of a protective mechanism are supportive evidence for the utility of unripened R. coreanus in traditional medicine for liver ailments.

• The Korean Journal of Physiology and Pharmacology
• /
• v.9 no.3
• /
• pp.173-177
• /
• 2005

The purpose of this study was to discern the critical point in skeletal muscle fatty acid oxidation by changing plasma free fatty acids (FFA) level in rat. In the study, 3 key steps in lipid oxidation were examined after changing plasma FFA level by acipimox. The rates of both palmitate and palmitoylcarnitine oxidation were decreased by decrease of plasma FFA level, however, carnitine palmitoyl transferase (CPT) 1 activity was not changed, suggesting CPT1 activity may not be involved in the fatty acid oxidation at the early phase of plasma FFA change. In the fasted rats, ${\beta}-hydroxy$ acyl-CoA dehydrogenase (${\beta}$-HAD) activity was depressed to a similar extent as palmitate oxidation by a decrease of plasma FFA level. This suggested that ${\beta}-oxidation$ might be an important process to regulate fatty acid oxidation at the early period of plasma FFA change. Citrate synthase activity was not altered by the change of plasma FFA level. In conclusion, the critical step in fatty acids oxidation of skeletal muscles by the change of plasma FFA level by acipimox in fasting rats might be the ${\beta}-oxidation$ step rather than CPT1 and TCA cycle pathways.

• The Korean Journal of Physiology and Pharmacology
• /
• v.12 no.4
• /
• pp.199-204
• /
• 2008

KIF1B${\beta}$ is a member of the Kinesin superfamily proteins (KIFs), which are microtubule-dependent molecular motors that are involved in various intracellular organellar transport processes. KIF1B${\beta}$ is not restricted to neuronal systems, however, is widely expressed in other tissues, even though the function of KIF1B${\beta}$ is still unclear. To elucidate the KIF1B${\beta}$-binding proteins in non-neuronal cells, we used the yeast two-hybrid system, and found a specific interaction of KIF1B${\beta}$ and the sorting nexin (SNX) 17. The C-terminal region of SNX17 is required for the binding with KIF1B${\beta}$. SNX17 protein bound to the specific region of KIF1Bf3 (813-916. aa), but not to other kinesin family members. In addition, this specific interaction was also observed in the Glutathione S-transferase pull-down assay. An antibody to SNX17 specifically co-immunoprecipitated KIF1B${\beta}$ associated with SNX17 from mouse brain extracts. These results suggest that SNX17 might be involved in the KIF1B${\beta}$-mediated transport as a KIF1B${\beta}$ adaptor protein.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.10
• /
• pp.1372-1380
• /
• 2013

Different endophytic fungi isolated from Himalayan Yew plants were tested for their ability to produce taxol. The BAPT gene (C-13 phenylpropanoid side chain-CoA acetyl transferase) involved in the taxol biosynthetic pathway was used as a molecular marker to screen taxol-producing endophytic fungi. Taxol extracted from fungal strain TBPJ-B was identified by HPLC and MS analysis. Strain TBPJ-B was identified as Fusarium redolens based on the morphology and internal transcribed spacer region of nrDNA analysis. HPLC quantification of fungal taxol showed that F. redolens was capable of producing $66{\mu}g/l$ of taxol in fermentation broth. The antitumour activity of the fungal taxol was tested by potato disc tumor induction assay using Agrobacterium tumefaciens as the tumor induction agent. The present study results showed that PCR amplification of genes involved in taxol biosynthesis is an efficient and reliable method for prescreening taxol-producing fungi. We are reporting for the first time the production of taxol by F. redolens from Taxus baccata L. subsp. wallichiana (Zucc.) Pilger. This study offers important information and a new source for the production of the important anticancer drug taxol by endophytic fungus fermentation.

• Reproductive and Developmental Biology
• /
• v.39 no.4
• /
• pp.97-104
• /
• 2015

Glucose is universal and essential fuel of energy metabolism and in the synthesis pathways of all mammalian cells. Glucose is the one of the major precursors of lactose synthesis using glycolysis result in producing milk fat and protein. During the milk fat synthesis, lipoprotein lipase (LPL) and CD36 are required for glucose uptake. Various morecules such as acyl-CoA synthetase 1 (ACSL1) activity of acetyl-CoA synthetase 2 (ACSS2), ACACA, FASN AGPAT6, GPAM, LPIN1 are closely related with milk fat synthesis. Additionally, glucose plays a major role for synthesizing lactose. Activations of lactose synthesize enzymes such as membranebound enzyme, beta-1,4-galactosyl transferase (B4GALT), glucose-6-phosphate dehydrogenase (G6PD) are changed by concentration of glucose in blood resulting change of amount of lactose production. Glucose transporters are a wide group of membrane proteins that facilitate the transport of glucose over a plasma membrane. There are 2 types of glucose transporters which consisted facilitative glucose transporters (GLUT); and sodium-dependent transport, mediated by the Na+/glucose cotransporters (SGLT). Among them, GLUT1, GLUT8, GLUT12, SGLT1, SGLT2 are main glucose transporters which involved in mammary gland development and milk synthesis. However, more studies are required for revealing clear mechanism and function of other unknown genes and transporters. Therefore, understanding of the mechanisms of glucose usage and its regulation in mammary gland is very essential for enhancing the glucose utilization in the mammary gland and improving dairy productivity and efficiency.

• Journal of Nutrition and Health
• /
• v.33 no.1
• /
• pp.23-32
• /
• 2000

The purpose of this study was to investigate the effcts of n-3, n-6 fatty arid and d-limonene on histopathological and biochemical changes in experimental rat hepatocarcinogenesis. To attain the above objectives, weanling Sprague-Dawley female rats were intraperitoneally injected twice with a dose of diethylnitrosamine(DEN, 50mg/kg body weight) and after 1 week 0.05% phenobarbital was provided with water. Sardine oil rich in n-3 fatty acids and corn oil rich in n-6 fatty acids were fed at 15% by weight and 5% d-limonene was added to the diet in each group. Ten weeks or 20 weeks after DEN treatment, rats were sacrifirced. The formation of glutathione S-transferase placental form positive(GST-P$\^$+/) foci was significantly decreased by the treatment of either sardine oil or d-limonene HMG-CoA reductase activity was not affected by dietary oils and d-limonene. Protein kinase C (PKC) activity was decreased by either sardine oil or d-limonene. Particularly d-limonene decreased the membrane PKC activity. Membrane Cholesterol/Phospholipid(Chol/PL) ratio was significantly decreased by d-limonene in sardine oil group. The data showed that GST-P$\^$+/ foci number was positively correlated with membrane PKC activity and serum cholesterol and negatively correlated with liver cholesterol level. These results suggest informations about the correlation between histopathological and biochemical changes such as cholesterol metabolism and PKC activity in experimental hepatocarcinogenesis and thereby can elucidate the possible mechanism related to the cancer inhibition.(Korean J Nutrition 33(1) : 23-32, 2000)

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.12
• /
• pp.1748-1755
• /
• 2016

An experiment was conducted to investigate the effect of niacin supplementation on hepatic lipid metabolism in rabbits. Rex Rabbits (90 d, n = 32) were allocated to two equal treatment groups: Fed basal diet (control) or fed basal diet with additional 200 mg/kg niacin supplementation (niacin). The results show that niacin significantly increased the levels of plasma adiponectin, hepatic apoprotein B and hepatic leptin receptors mRNA (p<0.05), but significantly decreased the hepatic fatty acid synthase activity and adiponectin receptor 2, insulin receptor and acetyl-CoA carboxylase mRNA levels (p<0.05). Plasma insulin had a decreasing tendency in the niacin treatment group compared with control (p = 0.067). Plasma very low density lipoproteins, leptin levels and the hepatic adiponectin receptor 1 and carnitine palmitoyl transferase 1 genes expression were not significantly altered with niacin addition to the diet (p>0.05). However, niacin treatment significantly inhibited the hepatocytes lipid accumulation compared with the control group (p<0.05). In conclusion, niacin treatment can decrease hepatic fatty acids synthesis, but does not alter fatty acids oxidation and triacylglycerol export. And this whole process attenuates lipid accumulation in liver. Besides, the hormones of insulin, leptin and adiponectin are associated with the regulation of niacin in hepatic lipid metabolism in rabbits.