• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.3
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• pp.183-190
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• 2011

This study was performed to assess the antioxidative properties of lipid from aquacultured mackerel Scomber japonicus fed with a diet fortified with conjugated linoleic acid (CLA) and ascidian Halocynthia roretzi tunic extracts by radical scavenging assay. The fish were separated into squid oil (Control) and 2.5% CLA (CA25) groups during the 8-week feeding period. The reducing power of each sample showed high levels of activity compared with ${\alpha}$-tocopherol and butylated-hydroxyanisol (BHA) at 0.2-1.0 mg/mL of lipid. Inhibition of linoleic acid oxidation in samples from Control and CA25 groups showed similar activity after 2 days of incubation at $40^{\circ}C$. The 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide, and hydroxyl radical scavenging activities of CLA and carotenoid-deposited sample (CA25) were higher than those of the Control group. The results indicated that the lipid extracted from the viscera of mackerel showed slightly higher antioxidant activities than that from the muscle.

• Food Science of Animal Resources
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• v.21 no.3
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• pp.215-226
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• 2001

The CLA used to add in diet was chemically synthesized by alkaline isomerization method with corn oil. To investigated the effects of conjugated linoleic acid(CLA) added diet feeding on CLA accumulation and blood characteristics of pork, a total of 64 Landrace was fed both CLA-free and CLA-added(0.3, 0.6 and 0.9%) diet for 1∼4 weeks. Cholesterol compositions in blood and CLA contents and fatty acid compositions of loin, belly, bone and skin were determined at 1, 2, 3 and 4 weeks after CLA added at fed. The HDL content in blood of all treatments was higher(P<0.05) than that of control and that of treatment 3 was higher(P<0.05) than that of other treatments among the CLA feeding periods. Palmitic, stearic and linolenic acids composition of loin and belly was increased but oleic, linoleic and arachidonic acids composition of them was decreased according to increasing the CLA feeding periods. CLA contents of loin and belly were higher than that of control and increased according to increasing the quantity of CLA and CLA feeding periods. CLA contents of bone and skin were higher than that of control, too. CLA content of skin was higher than that of bone. It was suggested that CLA could be accumulated in loin, belly, bone and skin by dietary CLA supplementation, and the CLA concentration and fatty acid composition in muscle could be affected by CLA level in diet and feeding period.

• Food Science of Animal Resources
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• v.18 no.4
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• pp.339-347
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• 1998

The effects of conjugated linoleic acid (CLA) in egg yolk on fatty acid composition and lipid oxidation during chilled storage (4$^{\circ}C$) were investigated. CLA was synthesized according to the method of alkali isomerization using safflower seed oil (SSO). A total of 250 hens (200 days of age) were fed control diet (commercial formula feed for han) or CLA-supplemented diet (1%, 2.5% and 5% CLA) or 5% SSO supplemented diet for 6 weeks, and eggs were collected for analysis of CLA, fatty acid compositons and lipid oxidation. Eggs from CLA-supplemented diets groups showed significantly (p＜0.05) higher CLA content compared to those of control group. The contents of linoleic, palmitic, and myristic acid were increased as well as CLA content by feeding a CLA-supplemented diet. However, the contents of oleic and arachidonic acids in egg yolks were decreased by dietary CLA supplementation. The pH of egg yolk increased by the levels of CLA during storage. The contents of CLA were not significantly (p＜0.05) changed during chilled storage for 28 days, whereas TBARS were significantly (p＜0.05) increased. It is suggested that lipid oxidation of egg yolk might be affected by the levels of CLA in egg yolk due to changes in fatty acid compositions.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.111-114
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• 2003

Conjugated linoleic acid (CLA), known to possess various beneficial effects such as anticarcinogenic, antioxidative, and cholesterol-depressing, has been used as a health supplementary food in Japan and the USA. Optimum condition for CLA production without causing changes in quality of kimchi was determined using Bifidobacterium sp., a CLA-producing microorganism, as a starter in culture broth, freeze-dried culture, and encapsulated culture. Results revealed encapsulation was most ideal for maintaining the ability of bacterium to produce CLA during kimchi fermentation. Exogenous linoleic acid (LA) which is a substrate for conversion to CLA was not added to kimchi since LA was already exists in red pepper. Changes in sensory properties of kimchi and production of CLA were measured after inoculation of the encapsulated starter. The optimum inoculation concentration of the encapsulated starter was 0.1% (w/w) for production of CLA without causing changes in kimchi taste.

• Journal of Nutrition and Health
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• v.37 no.3
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• pp.182-192
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• 2004

Conjugated linoleic acid (CLA) is the mixture of positional and geometric isomers of linoleic acid (LA), which is found abundantly in dairy products and meats. This study was performed to investigate the anticarcinogenic effect of CLA in HepG2 hepatoma cells. HepG2 cell were treated with LA and CLA at the various concentrations of 10, 20, 40, 80 uM each at different incubation times. After each incubation times, cell proliferation, fatty acids incorporation into cell, peroxidation and postaglandin E$_2$ (PGE$_2$) and thromboxane $A_2$ (TXA$_2$) for the eicosanoid metabolism were measured. LA treated HepG2 cells were increased cell growth 6 - 70％ of control whereas CLA increased cell death the half of those in LA group (p 〈 0.001). LA and CLA were incorporated very well into the cellular membranes four times higher than in control according to concentration and longer incubation times. Moreover, LA synthesized significantly arachidonic acids corresponding with LA concentration compared to CLA supplementation. The supplementation with LA increased intracellular lipid peroxides concentration corresponding with LA concentration and five times higher than those in CLA significantly at any incubation times (p 〈 0.001). PGE$_2$ and TXA$_2$ levels were three to twenty times lower in condition of CLA treatments than LA, respectively. Overall, the dietary CLA might change the HepG2 cell growth by the changes of cell composition, production of lipid peroxide. Since CLA have not changed the levels of arachidonic acid of cell membrane, which was sources of eicosanoids, eicosanoid synthesis was not increased in CLA compared to LA. Our results was suggest CLA has a possibility to protect the progress of atherosclerosis because CLA does not produce lipid production and endothelial contraction factors in liver.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1315-1328
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• 2004

Conjugated linoleic acid (CLA) is a mixture of positional and geometric isomers of octadecadienoic acid with two conjugated double bonds. Of more than a dozen isomers of CLA found naturally in dairy and meat products from ruminants, c-9, t-11 and t-10, c-12 are the two isomers with known physiological importance, including anticarcinogenic, antidiabetic, antilipogenic, and antiatherosclerotic effects. Positive effects of CLA on immune function and bone modeling have also been reported. In spite of the compelling findings in tissue cultures and experimental animal models, its effect, dose, and mechanism of action vis-à-vis specific isomers remains speculative. Results obtained from animal models are inconclusive and conflicting at times in humans, where the research data is limited. It appears that there is a long way to go before CLA could be accepted unequivocally as having definite effects in any or all of these physiological states and how such effects actually occur in humans. The objective of this review is to critically examine the available literature on potential health benefits of CLA observed in cell culture, animal models, and human subjects, wherever possible and to a certain extent the mechanism of action associated with these biological activities.

• Preventive Nutrition and Food Science
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• v.11 no.1
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• pp.1-5
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• 2006

Conjugated linoleic acid (CLA) is a group of positional and geometric isomers of linoleic acid that have been used to reduce the incidence, growth and metastasis of breast, colon, prostate and gastric cancer in animals. CLA could reduce tumor growth by altering angiogenesis; a process requiring associated angiogenic factors such as vascular endothelial growth factor (VEGF). In this study, we determined whether CLA could modulate the expression of VEGF in murine mammary tumor cells and adipocytes. The c9, t11-CLA isomer reduced VEGF transcripts and protein when mammary tumor cells were stimulated with PMA. That isomer also reduced VEGF expression in un stimulated mouse 3T3-L1 adipocytes. Since VEGF can be regulated by cyclooxygenase-2 (COX-2), we determined whether CLA could alter COX-2 enzyme expression and $PGE_2$ production. The c9, t11-CLA isomer reduced not only COX-2 enzyme expression but also $PGE_2$ production. Thus, c9, t11-CLA could modulate neovascularization by alteration of VEGF expression from mammary tumor cells and adipocytes by reducing COX-2 metabolites.

• Journal of Nutrition and Health
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• v.30 no.4
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• pp.442-450
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• 1997

Conjugated dienoic derivatives of linoleic acid(CLA) are a mixture of positional and geometric isomers of linoleic acid(LA). We previously found that CLA changes the fatty acid profile in chicken eggs and serum by decreasing monounsaturated fatty acids. Studies were conducted to explore the effects of CLA on fatty acid composition. Rabbits were fed a semisynthetic diet with or without CLA(0.5g CLA/rabbit/day) for 22 weeks. Compared to the control, rabbits fed CLA had significantly lower monounsaturated fatty acid levels(palmitoleic acid Cl6 : 1 by 50% and oleic acid Cl8 : 1, by 20%) in plasma lipids. We found similar differences in fatty acid composition in the liver and the aorta. The inhibitory effect of CLA on $\Delta$9 desaturation was confirmed in a human hepatoma cell line, Hep G2. CLA significantly decreased $\Delta$9 desaturation in 4-5 hours as shown by an increase in the ratio of Cl6 : 0 to C 16 1, This is apparently due to a decrease in $\Delta$9 desaturase(stearoyl-CoA desaturase, SCD) activity ; it was decreased more than 50%. These results, along with our previous findings, indicate that CLA is an inhibitor of $\Delta$9 desaturase in the liver.

• Preventive Nutrition and Food Science
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• v.5 no.2
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• pp.70-74
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• 2000

Most fatty acids in food matrices are triglyceride(TG) forms. Conjugated linoleic acid(CLA) produced from linoleic acid by microorganisms or chemicals is a free form. To apply the CLA to food systems, the TG containing CLA(designate CLA-TG) was synthesized by Lipozyme-catalyzed esterification method. An optimum reaction con-dition for the esterification of free CLA(FCLA) to glycerol by Lipozyme was determined as follows; Lipozyme(50mg) effectively catalyzed the esterification of CLA(500mg) to glycerol(1150mg) dissolved in isooctane (3ml) in a shaking incubator (200 rpm, 5$0^{\circ}C$) for 48 hr. Under the reaction condition, the resultant contained 52.4% CLA-TG as well as 31.1% Di-CLA-glycerol(CLA-DG), 7.6% mono-CLA-glycerol(CLA-MG), and 9.0% other CLA(un-reacted FCLA plus CLA dimer). These results suggest that the Lipozyme could be a useful enzyme for the production of CLA-TG to be employed in foods.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.278-285
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• 2003

This study was performed to compare early stage changes following the administrations of Conjugated Linoleic Acid (CLA), Carprofen and their combinations in the experimental canine cranial cruciate ligament rupture. Twenty five mongrel dogs were divided into five groups; Groups 1, 2, and 3 received a sectioning the cranial cruciate ligament (CCL) of the right stifle joint, and were administered CLA (250 mg/kg/day/orally), carprofen (4.4 mg/kg/day/orally), and their combinations for 4 weeks beginning 4 weeks postsurgery, respectively. Group 4 received sectioning CCL and no treatment. Group 5 was composed of unoperated normal dogs. The macroscopic observation of cartilage erosions on both the condyles and plateaus were evaluated, and the severity of the cartilage lesions and synovial inflammation was examined histologically at eight weeks after surgery. Histological examinations including hematoxylin and eosin stain, standard toluidine blue method, PAS technique and Masson trichrome technique, hematologic and radiographic evaluation were perfonned after experimental surgery. Slight yellowish discoloration of the surface was found in some of the experimental dogs. However macroscopic findings showed no significant differences among the groups. In radiographic findings, cranial displacement of the proximal tibia relative to the femoral condyles in all groups was observed but no significant differences among the groups was seen. This study showed that oral administration of CLA, carprofen and their combinations revealed no early stage change in the canine stifle joint following experimental rupture of the cranial cruciate ligament.