• Journal of Animal Science and Technology
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• v.53 no.3
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• pp.237-252
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• 2011

In this study, four different oils containing either CLA, GLA, GLA+Carnitine or corn oil (control) were supplemented to finishing pigs (average 70.8 kg initial BW) diet for 28 d of feeding period. To evaluate the values of the dietary fatty acids, especially in view of sensory and nutritional characteristics of pork; pig performances, carcass characteristics, serum cholesterol, neutrophil phagocytosis, TBARS, electronic nose flavor and fatty acids profile of pork were measured. There were no differences in daily gain and nutrients digestion among treatments, but daily feed intake of CLA enriched diet was lower (P<0.05) than that of other diets. There were no differences in backfat thickness, dressing percentage and carcass grade among pigs fed diets supplemented with different oils. Serum total cholesterol showed a tendency to be lowered in pigs fed GLA enriched diet. TBARS values during storage of pork were higher in belly from pigs fed control diet whereas the values of belly from pigs fed GLA+Carnitine diet were lower than others. However, difference in TBARS was not remarkable in adipose tissue and 4 weeks extended storage regardless of pork parts. Proportion of saturated fatty acids such as C16:0 and C18:0 were higher (P<0.05) in pork loin and thin skirt from pigs fed CLA enriched diet compared to those from other diets. There were no differences in fatty acids profiles of belly and adipose tissue. CLA accumulation in pork was increased by the dietary CLA supplementation and this could be also confirmed by a slight de novo synthesis of CLA in pork from pigs fed CLA free diets. GLA was selectively accumulated to pork adipose tissue and loin from pigs fed GLA enriched diets. There was no accumulation of GLA when GLA was not supplemented, indicating no de novo synthesis of GLA. Phagocytic activity was the highest (p<0.05) in neutrophil of pigs fed GLA+Carnitine supplemented diet, then, followed by pigs fed GLA supplemented diet. There was no difference in phagocytosis between control and CLA treatment although the phagocytosis was numerically lowest in pig fed CLA enriched diet. There were distinct differences in electronic nose flavor pattern among treatments regardless of the parts. This study showed that dietary supplementation of functional fatty acids like CLA or GLA was able to result in characteristic differences in feed intake, TBARS, fatty acids profile and flavor of pork, serum cholesterol regulation and neutrophil phagocytosis.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1256-1266
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• 2004

2-Bromooctanoic acid (2-BrOA) is known to block the formation of polyhydroxyalkanoic acid (PHA) in Pseudomonasfluorescens BM07 without any influence on the cell growth when grown on fructose, but it inhibits the cell growth when grown on octanoate (OA) (Lee et al., Appl. Environ. Microbiol. 67: 4963- 4974, 2001). We investigated the role of 2-BrOA in the PHA synthesis of the bacterium grown with mixtures of fructose and fatty acids. OA, 11­phenoxyundecanoic acid (1 1-POU), and 5-phenylvaleric acid (5-PV) were selected as model substrates. When supplemented with 50 mM fructose, all these carboxylic acids suppressed the formation of PHA from fructose, however, the ~-oxidation coenzyme A monomers derived from the carboxylic acids were efficiently polymerized, but the conversion yield [(mol of carboxylate substrate converted into PHA)/(mol of carboxylate substrate in the feed)] was low (e.g., maximally $\~53\%$ for 5 mM 11-POU). Addition of 2-BrOA (up to 5 mM) to the mixed carbon sources raised the conversion yield sensitively and effectively only at low levels of the acid substrates (e.g., 2 mM 1 1-POU or 5 mM OA): For instance, $100\%$ of 2 mM ll-POU were converted into PHA in the presence of 5 mM 2-BrOA, whereas only $\~10\%$ of the 1 1-POU were converted in the absence of 2-BrOA. However, at highly saturated suppressing levels (e.g., 5 mM ll-POU), 2-BrOA inhibitor showed no significant additional effect on the conversion ($60- 70\%$ conversion irrespective of 2-BrOA level). The existence of competitive and compensative relationship between 2­BrOA and all the carboxylic acid substrates used may indicate 'Present address: Section on Brain Physiology and Metabolism, Bldg. 10, Rm. 6N202, National Institute on Agmg, National Institute of Health, Bethesda, MD 20892, U.S.A. that all the acid substrate-derived inhibiting species bind to the same site as the 2-BrOA inhibiting species does. We, therefore, suggest that 2-BrOA can be used for efficiently increasing the yield of conversion of expensive substituted fatty acids into PHA and then substituted 3-hydroxyacids by hydrolyzing it.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.11
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• pp.1646-1652
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• 2016

Mammalian target of rapamycin complex 1 (mTORC1) is a central regulator of cell growth and metabolism and is sufficient to induce specific metabolic processes, including de novo lipid biosynthesis. Elongation of very-long-chain fatty acids 1 (ELOVL1) is a ubiquitously expressed gene and the product of which was thought to be associated with elongation of carbon (C) chain in fatty acids. In the present study, we examined the effects of rapamycin, a specific inhibitor of mTORC1, on ELOVL1 expression and docosahexaenoic acid (DHA, C22:6 n-3) synthesis in bovine mammary epithelial cells (BMECs). We found that rapamycin decreased the relative abundance of ELOVL1 mRNA, ELOVL1 expression and the level of DHA in a time-dependent manner. These data indicate that ELOVL1 expression and DHA synthesis are regulated by mTORC1 in BMECs.

• Korean Journal of Poultry Science
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• v.45 no.2
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• pp.109-118
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• 2018

A great progress in genetic selection, nutrition and management practices has contributed to the improved growth rate of broilers and egg production in laying hens. For the increased productivity of modern poultry, a healthy chicken liver needs to cope with the increased metabolic demands. The liver is the major site of de novo fatty acid synthesis; therefore, hepatic lipogenesis is crucial for producing better quality meat and eggs. When de novo lipogenesis exceeds the capacity of lipid metabolism and secretion, large amounts of lipids accumulate in the liver of broilers, leading to a fatty liver. Upon onset of egg-laying in hens, lipids including free fatty acids, triglycerides, and phospholipids are dramatically increased in blood plasma for the synthesis of yolk precursors in oocytes. Productive hens with fatty liver often have hemorrhagic syndrome and sudden death due to the heavy demands of yolk synthesis, which burdens the liver. Understanding the lipid metabolism and hepatic lipid disorders is a key point in the improvement of the growth and production of chickens. This review focuses on the recent studies on lipid metabolism, the hepatic lipid disorders, and the prevention or reduction of fatty liver in poultry.

• Journal of Microbiology and Biotechnology
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• v.23 no.11
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• pp.1569-1576
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• 2013

In mice, supplementation of t10,c12 conjugated linoleic acid (CLA) increases liver mass and hepatic steatosis via increasing uptake of fatty acids released from adipose tissues. However, the effects of t10,c12 CLA on hepatic lipid synthesis and the associated mechanisms are largely unknown. Thus, we tested the hypothesis that gut microbiota-producing t10,c12 CLA would induce de novo lipogenesis and triglyceride (TG) synthesis in HepG2 cells, promoting lipid accumulation. It was found that treatment with t10,c12 CLA ($100{\mu}M$) for 72 h increased neutral lipid accumulation via enhanced incorporation of acetate, palmitate, oleate, and 2-deoxyglucose into TG. Furthermore, treatment with t10,c12 CLA led to increased mRNA expression and protein levels of lipogenic genes including SREBP1, ACC1, FASN, ELOVL6, GPAT1, and DGAT1, presenting potential mechanisms by which CLA may increase lipid deposition. Most strikingly, t10,c12 CLA treatment for 3 h increased phosphorylation of mTOR, S6K, and S6. Taken together, gut microbiota-producing t10,c12 CLA activates hepatic de novo lipogenesis and TG synthesis through activation of the mTOR/SREBP1 pathway, with consequent lipid accumulation in HepG2 cells.

• Journal of Nutrition and Health
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• v.46 no.3
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• pp.226-238
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• 2013

Omega-3 polyunsaturated fatty acids are essential fatty acids because humans cannot synthesize them de novo and must obtain them in their diet. Fish and fish oil are rich sources of omega-3 fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Significant evidence of the beneficial role of dietary intake of omega-3 fatty acids in blood flow has been reported and putative mechanisms for improvement of blood flow include anti-thrombotic effects, lowered blood pressure, improved endothelial function, and anti-atherogenic effects. Edible oils containing omega-3 fatty acids were registered as functional ingredients in the Korea Health Functional Food Code. Although omega-3 fatty acids have been evaluated by the Korea Food and Drug Administration (KFDA) based on scientific evidence, periodic re-evaluation may be needed because emerging data related to omega-3 fatty acids have accumulated. Therefore, in this study, we re-evaluated scientific evidence for the effect of omega-3 fatty acids as a functional ingredient in health functional food on improvement of blood flow. A comprehensive literature search was conducted for collection of relevant human studies using the Medline and Cochrane, KISS, and IBIDS databases for the years 1955-2012. Search keywords were used by combination of terms related to omega-3 fatty acids and blood flow. The search was limited to human studies published in Korean, English, and Japanese. Using the KFDA's evidence based evaluation system for scientific evaluation of health claims, 112 human studies were identified and reviewed in order to evaluate the strength of the evidence supporting a relation between omega-3 fatty acids and blood flow. Among 112 studies, significant effects on improvement of blood flow were reported in 84 studies and the daily intake amount was ranged from 0.1 to 15 g. According to this methodology of systematic review, we concluded that there was possible evidence to support a relation between omega-3 fatty acid intake and blood flow. However, because inconsistent results have recently been reported, future studies should be monitored.

• Journal of Microbiology and Biotechnology
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• v.30 no.10
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• pp.1574-1582
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• 2020

Flavonoids have diverse biological functions in human health. All flavonoids contain a common 2-phenyl chromone structure (C6-C3-C6) as a scaffold. Hence, in using such a scaffold, plenty of high-value-added flavonoids can be synthesized by chemical or biological catalyzation approaches. (2S)-Naringenin is one of the most commonly used flavonoid scaffolds. However, biosynthesizing (2S)-naringenin has been restricted not only by low production but also by the expensive precursors and inducers that are used. Herein, we established an induction-free system to de novo biosynthesize (2S)-naringenin in Escherichia coli. The tyrosine synthesis pathway was enhanced by overexpressing feedback inhibition-resistant genes (aroG^fbr and tyrA^fbr) and knocking out a repressor gene (tyrR). After optimizing the fermentation medium and conditions, we found that glycerol, glucose, fatty acids, potassium acetate, temperature, and initial pH are important for producing (2S)-naringenin. Using the optimum fermentation medium and conditions, our best strain, Nar-17LM1, could produce 588 mg/l (2S)-naringenin from glucose in a 5-L bioreactor, the highest titer reported to date in E. coli.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.501-508
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• 2011

Previous studies suggest that polyunsaturated fatty acids with long carbon chains such as eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA) have several health benefits. However metabolic consequences of these fatty acids themselves and their regulation of transcriptional activity involving glucose utilization are not well established. Thus, the purpose of this study was to investigate how EPA influx affects cellular lipid accumulation and gene expressions involving $de$ $novo$ lipogenesis in hepatocyte cultures. Compared to oleic acid treatment, EPA treatment showed remarkably decreased cellular TG conversion and accumulation, along with phospholipids at a lower extent. As expected, EPA increased mRNA expression involving fatty acid influx and lipid droplet formation, but did not affect mRNA expression involving glucose utilization. EPA increased transcriptional activity of PPAR-${\alpha}$ and glucose responsive transcription factor when transcription factor binding protein was activated. Taken together, these data suggest that EPA decreases lipid accumulation through increases of the ${\beta}$-oxidation pathway without interruption of glucose utilization.

• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.1925-1931
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• 2017

Korean red pine (Pinus densiflora) bark extract, PineXol (PX), was investigated for its potential antioxidant and anti-inflammation effects in vitro. It was hypothesized that PX treatment ($25-150{\mu}g/ml$) would reduce the lipid synthesis in HepG2 hepatocytes as well as lipid accumulation in 3T3-L1 adipocytes. Hepatocytes' intracellular triglycerides and cholesterol were decreased in the PX $150{\mu}g/ml$ treatment group compared with the control (p < 0.05). Consequently, de novo lipogenic proteins (acetyl-CoA carboxylase 1, stearoyl-CoA desaturase 1, elongase of very long chain fatty acids 6, glycerol-3-phosphate acyltransferase 1, and sterol regulatory element-binding protein 1) were significantly decreased in hepatocytes by PX $150{\mu}g/ml$ treatment compared with the control (p < 0.05). In differentiated 3T3-L1 adipocytes, the lipid accumulation was significantly attenuated by all PX treatments (p < 0.01). Regulators of adipogenesis, including CCAAT-enhancer-binding proteins alpha, peroxisome proliferatoractivated receptor gamma, and perilipin, were decreased in PX $100{\mu}g/ml$ treatment compared with the control (p < 0.05). In conclusion, PX might have anti-obesity effects by blocking hepatic lipogenesis and by inhibiting adipogenesis in adipocytes.

• Journal of Applied Biological Chemistry
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• v.44 no.1
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• pp.6-11
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• 2001

An ${\omega}-3$ fatty acid desaturase gene which is involved in de novo synthesis of -Iinolenate was isolated from cDNA library of Perilla frutescens. A cDNA library was constructed with mRNA extracted from perilla seeds of 12 DAF. The cDNA clone consisting of 1317-bp open reading frame encoding 438 amino acids with a relative MW of 50kDa, was isolated and showed 65-83% similarities to other known genes. This cDNA is deduced to encode a plastidal ${\omega}-3$ fatty acid desaturase based on the fact that it has higher homology to plastidal ones than to microsomal ones and its N-terminal sequence shares several characteristics of transit peptides of chloroplast proteins. Southern blot analysis of genomic DNA indicated that more than one gene or alleles for ${\omega}-3$ fatty acid desaturase are present in the genome of perilla. Northern blot analysis showed that the ${\omega}-3$ fatty acid desaturase gene is mainly revealed in early developing seeds and has different expression patterns depending on tissue types compared to the microsomal ones.