• Food Science of Animal Resources
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• v.24 no.3
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• pp.303-309
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• 2004

Conjugated linoleic acid (CLA) is currently under intensive investigation due to its health benefits. A great deal of interest has been paid to the possible health-promoting roles of CLA, but there are not many studies available on the mechanism of CLA production by ruminal microorganisms. CLA is produced as an intermediate of the characteristic biohydrogenation process of linoleic acid(LA) in the rumen and its production has direct relationship to numerous environmental factors including particle association, substrate concentration, forage-to-grain ratio, pH, ionopore, bacterial cell density, etc. Some of these factors were known to affect hydrogenating activities of Butyrivibrio fibrisolvens A38 which is an active rumen bacterium in CLA production. Dairy cow is a main source of CLA, and its level could be increased by dietary manipulation changing the physiological environment of rumen bacteria such as B. fibrisolvens A38. Therefore, the effects of various factors on. ruminal biohydrogenation should be carefully considered to optimize not only CLA production, but also other fatty acid metabolism, both of which are directly affecting nutritional quality and functionality of dairy products. In this review, the relationship between various environmental factors and ruminal CLA production is discussed focusing on the CLA production of B. fibrisolvens A38.

• Journal of Nutrition and Health
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• v.35 no.2
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• pp.192-200
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• 2002

Conjugated linoleic acid (CLA) is a collective term for positional and geometric isomers of octadecadienoic acid in which the double bonds are conjugated. CLA has anticancer activity in a variety of animal cancer models, and cis-9, trans-11 (c9t11) and trans-10, cis-12(t10c12) CLA are the most predominant isomers present in the synthetic preparations utilized in these animal studies. To compare the ability of c9t11, t10c12 and an isomeric mixture of CLA to inhibit TSU-Prl cell growth, cells were incubated in a serum-free medium with various concentrations of these fatty acids. The isomeric mixture inhibited cell growth in a dose-dependent manner (1-3 $\mu$M) with a 41 $\pm$ 1% inhibition observed at 3 $\mu$M concentration after 48 hours. T10c12 also inhibited cell proliferation in a dote-dependent manner, However, the efficacy and potency of this isomer was much greater than that of the isomeric mixture with a 49 $\pm$ 2% inhibition observed at 0.3 $\mu$M concentration after 48 hours. By contrast, c9t11 slightly increased cell proliferation. To determine whether the growth-inhibiting effect of CLA is related to the changes in production of insulin-like growth factors (IGF) and IGF-binding proteins (IGFBP) by these cells, serum-free conditioned media were collected. Immunoblot analysis of conditioned media using a monoclonal anti-IGF-II antibody showed that both the isomeric mixture and t10c12 inhibited secretion of both mature 7,500 Mr and higher Mr forms of pro IGF-II, whereas c9t11 had no effect. Ligand blot analysis with 125I-IGF-II revealed the presence of two types of IGFBPs : 24,000 Mr IGFBP-4 and 30,000 Mr IGFBP-6. The production of IGFBP-4 slightly decreased at the highest concentrations of the isomeric mixture and t10c12. These results indicate that CLA inhibits human prostate cancer cell growth, an effect largely due to the action of t10c12. The growth inhibition may result, at least in part, from decreased production of IGF-II and IGFBP-4 by these cells.

• Journal of Nutrition and Health
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• v.34 no.8
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• pp.896-904
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• 2001

Conjugated linoleic acid(CLA) is a group of positional and geometric isomers of linoleic acid(LA) and exhibits anticarcinogenic activity in multiple experimental animal models. Cis-9,trns-11(c9t11) and trans-10,cis-12(t10c12) CLA are the principal isomers found in foods. The present study was performed to determine whether CLA and the two isomers inhibits HT-29 cell proliferation and to assess whether such an effect was related to changes in secretion of eicosanoids. Cells were incubated in serum-free medium with various concentrations(0 to 20$\mu$M) of CLA or LA. CLA inhibited cell proliferation in a dose-dependent manner, with maximal inhibition(70 $\pm$ 1%) observed at 20$\mu$M concentration after 96 hours. However, LA had no effect at the same concentration range. To compare the ability of c9f11 and t10c12 to inhibit cell proliferation, cells were incubated with increasing concentrations(0 to 4$\mu$M) of these isomers. T10c12 inhibited cell proliferation in a dose-dependent manner. A 66 $\pm$ 2% decrease in cell number was observed within 96 hours after addition of 4$\mu$M t10c12. By contrast, c9t11 had no effect. The concentrations of CLA and the two isomers in the plasma membrane were increased when they were added to the incubation medium. However, they did not alter the levels of arachidonic acid in plasma membrane. To assess whether the proliferation inhibiting effect of CLA was related to changes in eicosanoid production, prostaglandin E$_2$(PGE$_2$) and leukotriene B$_4$(LTB$_4$) concentrations in conditioned media were estimated by a competitive enzyme immunoassay. Both CLA and t10c12 increased the production of materials reactive to PGE$_2$ and LTB$_4$ antibodies in a dose-dependent manner. By contrast, c9t11 had no effect. These results indicate that inhibition of HT-29 cell proliferation by CLA is attributed to the effect of the t10v12 isomer. The materials reactive to PGE$_2$ and LTB$_4$ antibodies may inhibit growth stimulatory effect of arachidonic acid-derived eicosanoids on HT-29 cell proliferation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.1000-1005
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• 2004

Structured lipids (SLs) were synthesized by acidolysis of crude oils (corn and peanut oil) and conjugated linoleic acid (CLA) with a molar ratio of 1:3 (extracted oil:CLA) in a shaking water bath. The reaction was performed for various reaction time (1, 2, 3, 6 and 24 hr) at 55$^{\circ}C$ with 175 rpm catalyzed by sn -1,3 specific IM 60 lipase from Rhizomucor miehei. The content of the incorporated CLA increased with the prolonged reaction time, showing 7.5∼9.3 ㏖% in the synthesized SL triacylglycerol molecules from the extracted corn and peanut oil. However, total tocopherol content in SLs decreased up to about 20% compared to the content in extracted oils. Among the CLA isomers, 6.3∼7.5 ㏖% of cis 9,trans 11- and trans 10,cis 12-CLA known as physiologically active compounds are contained in corn and peanut SLs.

• Applied Biological Chemistry
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• v.40 no.4
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• pp.283-288
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• 1997

The antioxidant activities of Korean Red Ginseng Extract(RGE) and ${\alpha}-tocopherol$, as reference compound, were tested with HPLC and fluorometry which measure the MDA after reacting an aqueous 1% linoleic acid buffer solution, and LDL(1 mg protein/ml) buffer solution with $H_2O_2{\;}and{\;}FeCl_2$. The generation of conjugated-diene in LDL(0.25 mg protein/ml) was also measured by spectrometry. MDA determination showed the antioxidant effect on linoleic acid oxidation with oxidation inhibition ratio of 71.8% and 76.1%, respectively, by addition of 1000 ppm RGE and 100 ppm ${\alpha}-tocopherol$. LDL(1 mg protein/ml) oxidation was inhibited by 25.2% and 21.2%, respectively, by addition of 200 ppm REG and 100 ppm ${\alpha}-tocopherol$. The generation of conjugated diene in LDL(0.25 mg protein/ml) was also inhibited by 44.2%, by addition of 50 ppm RGE.

• Journal of Applied Biological Chemistry
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• v.49 no.4
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• pp.131-134
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• 2006

The in vitro anti-fungal activity of hydroxylated fatty acids obtained from microbial conversion by Psuedomonas aeruginosa PR3 using ricinoleic acid(RA), eicosadienoic acid(EDA) and conjugated linoleic acid(CLA) as substrates, was investigated. Bioconverted hydroxylated fatty acids showed different anti-fungal activities potentials against the range of phytopathogenic fungi such as Botrytis cinerea, Rhizoctonia solani, Fusarium oxysporum, Sclerotonia sclerotiorum, Colletotricum capsici, Fusarium solani and Phytophthora capsici. RA and EDA showed up to 50% fungal mycelial inhibition at the concentration of $5{\mu}l\;ml^{-1}$. RA, EDA and CLA also exhibited anti-fungal activities with minimum inhibitory concentration(MIC), ranging from 500 to $1000{\mu}g\;ml^{-1}$. Screening was also carried out using varied concentrations of bioconverted RA and EDA for determining the anti-fungal effect on the spore germination of different fungi. Bioconverted RA and EDA showed a considerable degree of spore germination inhibition.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.104.2-105
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• 2003

Plant steryl esters have good effects on plasma cholesterol level and are used as functional food ingredient. Conjugated linoleic acid (CLA) presents mainly in animal foods and has a good benefit and medium chain fatty acids (MCFAs) are a rapid energy source for human. In this study, we produced the ${\beta}$-sitosterol esters from CLA and MCFAs using various lipases as catalysts. Among lipases, AYS (from Candida rugosa) was the most effective for synthesis of ${\beta}$-sitosterol esters in the presence of water (24.35% conversion) or hexane (25.33% conversion). The second esterification extent was obtained by lipase AK (from Pseudomonas sp), showing 10.26% conversion in water and 15.94% conversion in hexane, respectively. The reaction condition was 1:3 molar ratio (${\beta}$-sitosterol:fatty acid, 1:3) and stirred (175 rpm) at 55$^{\circ}C$ in water bath shaker for 48h.

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.71.1-71.1
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• 2008

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.164.2-165
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• 2003

Structured lipids (SLs) are defined as triacylglycerols to change the fatty acid composition in the glycerol backbone and lipases are known as a powerful tool for the syntheses of SLs. Structured lipid from corn oil, capric acid, and conjugated linoleic acid (CLA) by transesterification reaction and using several amounts of immobilized lipase RM IM (from Rhizomucor miehei) was studied, and 4% of lipase amount was selected for further study as the optimal amount. Comparison the chemical properties (free fatty acid value, iodine value, saponification value, tocopherols, and color analysis), solidification behavior, and volatile fractions (from headspace SPME GC-MS) between com oil and SL com oil was obtained.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.337.2-337.2
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• 2002

Conjugated linoleic acid (CLA) is a potent inhibitor of mammary carcinogenesis. Cancer cells produce various angiogenic factors which stimulate host vascular endothelial cell mitogenesis and chemotaxis for their growth and metastasis. Basic fibroblast growth factor (bFGF) is a potent angiogenic factor that is expressed in many tumors. In this study. we found that CLA decreased bFGF-induced endothelial cell proliferation and DNA synthesis in a dose-dependent manner. However, CLA did not inhibit endothelial cell migration. Furthermore CLA showed a potent inhibitory effect on embryonic vasculogenesis and bF GF-induced angiogenesis in vivo. Collectively. these results suggest that CLA selectively inhibis the active proliferating endothelial edll induced by bFGF. which may explain its anti-carcinogenix properties in vivo.