• Preventive Nutrition and Food Science
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• v.6 no.1
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• pp.19-22
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• 2001

Conjugated linoleic acid (CLA) exhibits potent anti-carcinogenic and other biological activities in several animal models. We report here that dietary CLA, chemically synthesized from corn oil, accumulates I silkworm, Bombyx mori, which is used as therapeutic agent for diabetes in Korea and Japan. Mulberry leaves treated with 0.1 or 10% CLA in ethanol were supplied to silkworms from the end of 3rd instar to the 3rd day of the 5th instar. Fresh mulberry leaves or leaves treated with 10% corn oil in ethanol were fed as a check treatment. the amount of total lipids in the larval body ranged from 17.4 to 19.1mg/g of body tissue, which was not significantly affected by the source of the diets. No CLA was found in the control silkworms. But the level of CLA significantly increased to 83.5 mg/g of fat, when fed with mulberry leaves treated with 10% CLA. Only trace amounts of CLA were detected in the larvae reared with check leaves and 0.1% CLA-treated leaves. Mulberry leaves treatd with corn oil or CLA were not palatable to the larvae, resulting in a reduction of larval weight. These results suggest that silkworms containing CLA in body lipids could be producted by dietary CLA.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.7
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• pp.1031-1035
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• 2002

This study was carried out to obtain conjugated linoleic acid (CLA) producing lactic acid bacteria for further study on the enzymes related to the production of CLA which has gained considerable attention and on the development as a probiotic culture. Total 34 lactic acid bacteria were isolated from 19 feces samples of healthy babies. CLA forming ability was measured spectrophotometrically by the modification of linoleate 12-cis, 11-trans-isomerase activity measuring method, and CLA of the cultures were extracted, methylated, and examined by HPLC analysis. CLA methyl ester of only one culture showing the highest value of CLA forming ability could be detected by HPLC analysis. The culture was found to be Gram positive, rods and catalase negative. It grows at $45^{\circ}C$ but not at $15^{\circ}C$, and was identified to be Lactobacillus fermentum on the basis of the biochemical characteristics and the utilization of substrates. These results provide an efficient experimental method to screen CLA producing lactic acid bacteria.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.411-414
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• 2004

Although conjugated linoleic acid (CLA) exerted potent antitumor activities in several animal models, application of CLA as a bioactive ingredient has been limited due to its hydrophobicity. This study was designed to determine the antitumor activity of arginine-CLA complex (Arg-CLA), a hydrophilic form of CLA. Mouse forestomach cancer was induced by gavage with benzo(a)pyrene (B(a)p) for 4-weeks prior to Arg-CLA (0.2 and 0.5％) feeding. Complete necropsies were performed to determine the number, size and locations of all the forestomach tumors at 20 weeks post-B(a)P administration. All mice in the B(a)P group developed tumors, and tumor incidences were decreased by 31 ％ and 44％ in 0.2％ and 0.5％ Arg-CLA-fed groups, respectively, whereas no decrease was observed when Arg or com oil was given alone. Our results suggest that Arg-CLA suppresses mouse forestomach cancer.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.803-807
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• 2009

Solid fats were esterified with solid phase of rice bran oil (S-RBO), palm stearin (PS), and conjugated linoleic acid (CLA) at 2 substrate mole ratios (S-RBO:PS:CLA of 1:1:2 and 1:3:4). The major fatty acids were palmitic, oleic, and CLA in 36 hr products. The solid fat content (SFC) of the 1:1:2 product was 12.8% while the SFC of 1:3:4 product was 45.1% at $20^{\circ}C$. The SFCs after $20^{\circ}C$ reduced when the reaction time increased from 1 to 36 hr, suggesting that the change of triacylglycerol species was augmented by extending reaction time.

• Food Science and Biotechnology
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• v.17 no.6
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• pp.1261-1264
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• 2008

In the present study, a randomized, double-blind, placebo-controlled trial to determine the effect of conjugated linoleic acid (CLA) supplementation (50:50 ratio of cis-9, trans-11 and trans-10, cis-12 isomers) for 8 weeks on body composition and biochemical parameters in healthy overweight/obese (body mass index, BMI${\geq}23\;kg/m^2$) Korean subjects was performed, Thirty participants (3 males and 27 females) were randomized to receive placebo (2.4 g olive oil/day) or 2.4g/day CLA (mixture containing 36.9% of cis-9, trans-11 and 37.9% of trans-10, cis-12). Eight weeks of CLA supplementation significantly decreased body weight by -0.75kg, BMI by $-0.27\;kg/m^2$, and hip circumference by -1.11 cm. The reduction of body weight was ascribed to the reduction of body fat mass (-0.59 kg) and lean body mass (-0.18 kg), although these changes were not significant. No significant differences in serum lipid profiles, liver function enzyme activities, and protein concentration were observed in either the CLA or placebo groups. These results indicate that short tenn supplementation (8 weeks) with CLA (2.4 g/day) may decrease body weight in Korean overweight/obese subjects.

• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.739-747
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• 2018

The low solubility and high-cost recovery of Propionibacterium acnes polyunsaturated fatty acid isomerase (PAI) are key problems in the bioproduction of high value-added conjugated linoleic acid (CLA). To improve the solubility of recombinant PAI, six chaperone proteins were coexpressed with PAI. Introduction of GroELS proteins dramatically improved the PAI solubility from 29% to 97%, with increased activity by 57.8%. Combined expression of DnaKJ-GrpE and GroELS proteins increased the activity by 11.9%. In contrast, coexpression of DnaKJ-GrpE proteins significantly reduced the activity by 57.4%. Plasmids pTf16 harboring the tig gene and pG-Tf2 containing the tig and groEL-groES genes had no visible impact on PAI expression. The lytic protein E was then introduced into the recombinant Escherichia coli to develop a cell autolysis system. A 35% activity of total intracellular PAI was released from the cytoplasm by suspending the lysed cells in distilled water. The PAI recovery was further improved to 81% by optimizing the release conditions. The lipase from Rhizopus oryzae was also expressed in E. coli, with an extracellular activity of 110.9 U/ml. By using the free PAI and lipase as catalysts, a joint system was established for producing CLA from sunflower oil. Under the optimized conditions, the maximum titer of t-10,c-12-CLA reached 9.4 g/l. This work provides an effective and low-cost strategy to improve the solubility and recovery of the recombinant intracellular PAI for further large-scale production of CLA.

• Preventive Nutrition and Food Science
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• v.6 no.1
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• pp.57-61
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• 2001

Conjugated linoleic acid (CLA), when incorporated into mouse liver microsomal membranes, selectively inhibits the mutagenesis of 2-amino-3-methylimidazo[4,5-f] quinoline (IQ). Nine-week old female ICR mice were given (p.o.) 0.1 mL olive oil alone (control), 0.1 mL olive oil plus 0.1 mL linoleic acid, or 0.1 mL olive oil plus 0.1 mL CLA, twice weekly for four weeks. The animals were then sacrificed and liver S-9 fractions were prepared. Activation of IQ for mutagenesis by the liver S-9 from CLA-treated mice was significantly reduced in comparison wit liver S-9 from control or linolic acid-treated mice. By contrast, the activation of 7,12-dimethylbenz[a] anthracene (DMBA) and benzo[a] pyrene (BP) was unaffected. Hence, CLA incorporated into phospholipids may selectively affect cytochrome P450 isozymes responsible for activating IQ, but not those which activate BP or DMBA. The addition of free CLA or the methyl esters of CLA, linoleic acid, or oleic acid, to control S-9 inhibited the activation of all three mutagens (IQ, BP, and DMBA).

• Preventive Nutrition and Food Science
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• v.5 no.2
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• pp.86-92
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• 2000

Conjugated linoleic acid(CLA) refers to a collective term of positional and geometric isomers of linoleic acid, which are different in their biological activities. The predominant isomer of CLA in animal tissues is cis-9, trans-11; smaller amounts of trans-10, cis-12 CLA isomers, CLA methyl ester (CLA-ME) was chemically syn-thesized from linoleic acid by the alkaline isomerization method. The synthetic CLA-ME, mainly composed of cis-9, trans-11 CLA and trans-10, cis-12 CLA, was dissolved in acetone, stored at 68$^{\circ}C$ for 1 day, and the supernatant(cis-9, trans-11 CLA-Me) was separated from the precipitate (trans-10, cis-12 CLA-Me). After the processes were repeated three times at -68$^{\circ}C$, the whole processes were repeated three times at -71$^{\circ}C$ in order to increase the purity of these two isomers. The cis-9, trans-11 CLA-Me and trans-10, cis-12 CLA isomers were further purified by the urea adduct. Purities of the cis-9, trans-11 CLA-Me and trans-10, cis-12 CLA-Me were 90.3 and 99.9%, respec-tively. This method could be employed for the preparation of a large quantity of highly purified cis-9, trans-11 CLA-Me or trans-10, cis-12 CLA-Me from synthetic CLA-Me.

• Food Science of Animal Resources
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• v.33 no.4
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• pp.487-492
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• 2013

The objective of this study was to examine the effect of supplementation of high linoleic ($C_{18:2}$) oil or high linolenic ($C_{18:3}$) oil to the diet on milking performance and content of conjugated linoleic acid (CLA) isomers in goat milk fat. Forty five dairy goats (Sumnen, 25 d post-partum, $62.5{\pm}1.2kg$) were randomly assigned to three treatment groups with each group of 15 dairy goats. The goats were fed a basal diet (CON) consisting 1.2 kg concentrate and 1.2 kg chopped hay (0.6 chopped alfalfa and 0.6 kg hay) daily with 4% soybean oil (SO) or 4% linseed oil (LO). Daily feed intake was not influenced (p>0.05) but daily milk yield (p<0.001) and milk fat yield (p<0.001) were significantly increased by supplementation of oils. Supplementation of oils decreased the short chain fatty acid, medium-chain fatty acid and saturated fatty acid in goat milk fat while increased trans vaccenic acid (trans-11-$C_{18:1}$, TVA), oleic acid ($C_{18:1}$), $C_{18:2}$, $C_{18:3}$, cis-9, trans-11-CLA (c9, t11-CLA), trans-10, cis- 12-conjugated linoleic acid (t10, c12-CLA), unsaturated fatty acids, mono unsaturated fatty acid and long-chain fatty acid in goat milk fat (p<0.001). Especially, c9, t11-CLA, t10, c12-CLA and ${\omega}-3$ fatty acid ($C_{18:3\;n-3}$) in milk fat were highest when goat fed LO diet. Based on the result, it is suggested that supplementation of linseed oil should be an effective method to increase CLA isomers and ${\omega}-3$ fatty acid in goat milk fat without negative effect on lactating performance.

• Journal of Food Hygiene and Safety
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• v.22 no.3
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• pp.145-150
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• 2007

Conjugated linoleic acid (CLA) reduces fat deposition in several mammalian species. The proposed mechanisms for this effect are reduced preadipocyte proliferation and differentiation. The objective of this study was to investigate the inhibitory effects of diglyceride (DG), CLA, DG-CLA of proliferation and differentiation of 3T3-L1 preadipocytes. Cell viability was determined using WST-8 analysis and cell differentiation was determined by glycerol-3-phosphate dehydrogenase (GPDH) activity. Lipid accumulation in differentiating 3T3-L1 cells was measured by Oil red O staining. The proliferation of preconfluent 3T3-L1 cells by treatments of DG, CLA, and DG-CLA was reduced in a dose-dependent manner. CLA among them was the most effective in reduction of viable cells with increasing concentrations. Treatments of the DG, CLA, and DG-CLA at the concentration of $100{\cdot}\ddot{I}g/ml$ for 48h significantly inhibited differentiation of 3T3-L1 cells (p<0.05). In addition. cytoplasmic lipid accumulation during differentiation of the 3T3-L1 preadipocytes was also inhibited by treatments of the test solutions. DG-CLA was the most effective in the inhibition of differentiation and lipid accumulation in 3T3-L1 cells. These results indicate that the DG including CLA as fatty acids is more effective for anti-obesity than DG or CLA alone and that consumption of DG-CLA as a dietary oil may give a benefit for controlling overweight in humans.