• Biotechnology and Bioprocess Engineering:BBE
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• 제10권4호
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• pp.357-361
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• 2005

The bioconversion of linoleic acid (LA) to conjugated linoleic acid (CLA) was investigated to examine LA-adaptation of Bifidobacterium breve KCTC 3461 to additions of 1 to 5 mg/mL of LA overtime. To induce LA-adaptation, B. breve KCTC 3461 was treated with LA, according to three schemes. For LA-adapted B. breve the maximum concentration of CLA, $300\~350{\mu}g/mL$, was obtained in cys-MRS medium containing 1 mg/mL of LA. The CLA production significantly increased with increasing LA concentration, from 1 to 4 mg/mL, but the conversion of LA to CLA gradually decreased. The CLA production capability of B. breve, and its tolerance, improved significantly with LA-adaptation. The addition of LA (1 mg/mL) into the culture broth after 24 h of cultivation in a 100-mL media bottle was most effective at promoting CLA production. In a 2.5-L stirred-tank bioreactor, the observed conversion and productivity of $56.6\%\;and\;35.4{\mu}gmL^{-1}h^{-1}$, respectively, by LA-adapted B. breve were approximately 6.6 and 9.8 times higher than those of LA-unadapted B. breve.

• Journal of Nutrition and Health
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• 제37권3호
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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.

• Preventive Nutrition and Food Science
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• 제4권3호
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• pp.203-208
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• 1999

The effect of the polyunsaterated fatty acids, linoleic acid(LA), arachidonic acid(AA) and conjugated dienoic linoleic acid(CLA) on IEC-6 cells (rat intestinal cell)proliferation and cell transduction have been determined in vitro. IEC-6 cells proliferation was assessed by cell growth and [3H]-thymidine incroporation analysis. At 10 μM concentration , the proliferationof cells supplemented with AA or LA was significantly higher than that of CLA. [3H]-thymidine uptake showed the same results. LA and AA increased [3H]-thymidine uptake more than CLA. The stimulatory effect of LA or AA was even more pronounced in the presence of IGF. Both cell number analysis and [3H]-thymidine incorporation revealed that IEC-6 cell proliferation was influenced differently by exogenous free fatty acids, in which AA or LA stimulated IEC-6 cell proliferation and CLA inhibited it. Tyorosine phosphorylation provides a key switch to regulate celluar acitivity in response to extracellular stimuli. At 20 μM and 10μM, AA with IGF-1 stimulated protein tyrosine phophorylation in IEC-6 cells, but LA's impact was less than that of AA. CLA and CLA with IGF-1 inhibited protein tyrosine phosphorylation in IEC-6 cells. These results suggest there is a possible correlation between cell proliferation and IGF receptor tyrosine knase activity driven by AA.

• Food Science and Biotechnology
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• 제15권2호
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• pp.317-320
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• 2006

Octadeca-9,12-dienyl-3,4,5-hydroxybenzoate (GA-LA) was chemically synthesized from gallic acid and linoleic acid ester, and its biological functions were tested. Radical-scavenging activity of GA-LA was comparable to those of gallic and ascorbic acids at 0.24 mM, and tyrosinase inhibition effect was higher than that of ascorbic acid. Gallic and linoleic acids did not show any tyrosinase activity. Results of cyclooxygenase (COX) inhibition effect indicate GA-LA has higher selectivity in COX-1 inhibition. GA-LA from gallic and linoleic acids could be used as functional reagent for antioxidative, skin-whitening, and anti-inflammatory effects in food, pharmaceutrical, and cosmetic industries.

• Preventive Nutrition and Food Science
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• 제2권1호
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• pp.29-34
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• 1997

In order to determine the effectiveness of linoleic acid(LA) to inhibit carcinogens/mutagens-induced mu-tagenesis, Ames test using Salmonella typhimurium TA100 and the SOS chromotest using E. Coli PQ37, were carried out. The inhibitory effect of LA(1%) on the Ames mutagenicity test were 98%, 78%and 69% mediated by aflatoxin B₁(AFB₁), N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) and 4-nitroquinoline-1-oxide(4-NQO), respectively. LA exhibited a strong antimutagenic activity aganist indirect mutagen, AFB₁whereas exhibited the same concentration of LA showed weaker inhibitory effects on direct mutagens of MNNG and 4-NQO than that AFB₁. LA also reduced the SOS responses induced by MNNG and 4-NQO significantly. This result showed a possibility that LA can be a protective agent in early step of cancinogenesis.

• 한국응용과학기술학회지
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• 제4권2호
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• pp.25-30
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• 1987

In order to investigate the effect to antioxygenic substances in Pine Needles on the photooxidation of linoleic acid (linoleic acid 100mg/10ml ethanol) added antioxidants and antioxygenic substances in Pine Needles was irradiated by the tungsten lamp attached with red fitter. The Photo oxidation of linoleic acid (LA) was conformed with Lea method and rhodan method. The following results were obtained: 1. Photooxidation of LA was greatly increased the presence of photosensitizer. However the Photo oxidation of LA without photosensitizer was smoothly increased by the irradiation. 2. The Photo oxidation of LA without irradiation occured quite lately whether photosensitizer was present or absent. 3. Photooxidation of LA under the presence of photosensitizer was inhibited by the addition of $dl-{\alpha}-tocopherol$ and the acetone fraction of methanol extract of Pine Needles but inhibited by BHT. Photooxidation of LA increased gradually as the addition of BHT increased but decreased gradually as that of acetone fraction increased.

• Journal of Microbiology
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• 제45권3호
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• pp.199-204
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• 2007

The objective of this study was to evaluate the effect of soluble carbohydrates (glucose, cellobiose), pH (6.0, 6.5, 7.0), and rumen microbial growth factors (VFA, vitamins) on biohydrogenation of linoleic acid (LA) by mixed rumen fungi. Addition of glucose or cellobiose to culture media slowed the rate of biohydrogenation; only 35-40% of LA was converted to conjugated linoleic acid (CLA) or vaccenic acid (VA) within 24 h of incubation, whereas in the control treatment, 100% of LA was converted within 24 h. Addition of VFA or vitamins did not affect biohydrogenation activity or CLA production. Culturing rumen fungi at pH 6.0 slowed biohydrogenation compared with pH 6.5 or 7.0. CLA production was reduced by pH 6.0 compared with control (pH 6.5), but was higher with pH 7.0. Biohydrogenation of LA to VA was complete within 72 h at pH 6.0, 24 h at pH 6.5, and 48 h at pH 7.0. It is concluded that optimum conditions for biohydrogenation of LA and for CLA production by rumen fungi were provided without addition of soluble carbohydrates, VFA or vitamins to the culture medium; optimum pH was 6.5 for biohydrogenation and 7.0 for CLA production.

• Preventive Nutrition and Food Science
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• 제5권2호
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• pp.114-118
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• 2000

The inhibitory effects of doenjang extracts and linoleic acid(LA) which was identified as one of the active compounds in doenjang on the growth of human cancer cells were studied, comparing to the actions on normal cells. Methanol extract and hexane fraction from doenjang exhibited the strong growth inhibitory effect on HT-29 human colon carcinoma cells. Inhibitory effects of chloroform, ethyl acetate, butanol and aqueous fractions on the cancer cells were observed, moderately or weakly. When cell counts of SNU-C$_1$human colon carcinoma cells were determined daily for 6 days, the inhibitory effect of hexane fraction on this cell line was higher than that of the methanol extract from doenjang. LA completely suppressed the growth of SNU-C$_1$cells after 4 days, while conjugated linoleic acid(CLA) resulted in 98% inhibition after 6 days. With the addition of LA and other free fatty acids such as stearic acid, oleic acid, linolenic acid and ${\gamma}$-linolenic acid (${\gamma}$-LnA) to the culture system, the growth of HT-29 cells and SNU-C$_1$cells was greatly suppressed after 6 days. Inhibitory effects of LA ${\gamma}$-LnA on the growth of these cells were stronger than other fatty acids. On the growth of AZ-521 human gastric carcinoma cells, LA and CLA completely cuppressed the growth of the cells after 4 days and 3 days, respectively. At the level of 0.001%~0.01% of LA, there was no cytotoxic effect on normal rat kidney cells and normal intestine human cells. These results showed that LA, a major active compound of doenjang, had strong inhibitory effects on the growth of human cancer cells without damaging normal cells.

• 한국식품영양과학회지
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• 제33권8호
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• pp.1348-1352
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• 2004

인체의 장관에서 유래한 200여 Bifidobacteria 균주를 대상으로 CLA 생산능을 조사한 결과, 공시균주 1종과 국내의 유아로부터 분리한 12개 균주가 기질로 첨가한 LA를 CLA로 전환하였으며, 각 CLA 생산 균주들에 의한 CLA 이성체는 90% 이상이 cis-9, trans-11 CLA이었다. CLA 생산능과 전환율이 가장 높은 Bifidobacterium sp. KHU 141 균주를 사용하여 발효유를 제조하였을 때, 발효유의 CLA 함량은 대조구보다 39.6 mg/100 g 증가하여 CLA의 생리활성 효과를 기대할 수 있는 발효유의 생산에 사용할 수 있는 균주로 나타났다. Bifidobacterium sp. KHU 141에 의한 fermenter에서의 발효유 제조 시 lauric acid, myristric acid, palmitic acid, oleic acid 및 linolenic acid 함량은 큰 변화를 보이지 않았으나, LA 함량은 감소하고 CLA 함량은 증가하여 배양 24시간 및 48시간 후에 각각 소비된 LA의 86.0%및 84.8%가 CLA로 전환되었다. Bifidobacterium sp. KHU 141에 의한 CLA 생산은 배양 24시간과 48시간 사이에 큰 차이가 없었으며 fermenter에서의 CLA 생산능도 bottle이나 시험관을 이용하여 발효한 경우와 같이 안정적으로 유지되었다.

• Journal of Nutrition and Health
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• 제36권3호
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• pp.270-279
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• 2003

Conjugated linoleic acid (CLA) is a group of positional and geometric isomers of linoleic acid (LA) and exhibits anticarcinogenic activity in a variety of animal models. We have previously observed that CLA inhibited the growth of Caco-2 cells, a human colon adenocarcinoma cell line. The present study was performed to determine whether the growth inhibitory effect of CLA is related to change in secretion of IGF- II and/or IGF-binding proteins (IGFBPs) that have been shown to regulate Caco-2 cell proliferation by an autocrine mechanism. Cells were incubated in serum-free medium with various concentrations of CLA or linoleic acid (LA). Immunoblot analysis of 24-hours, serum-free, conditioned medium using a monoclonal anti-IGF-IIantibody revealed that Caco-2 cells secreted both mature 6,500 Mr and higher Mr forms of pro IGF-II. The levels of pro IGF-II and mature IGF-IIwere decreased by 43 $\pm$ 2% and 53 $\pm$ 6%, respectively by treatment with 50 $\mu$ M CLA. LA slightly increased pro IGF- II levels. Results from Northern blot analysis showed that CLA decreased IGF-II mRNA levels at 50 $\mu$ M concentration suggesting that CLA regulation of IGF-II protein expression occurs partly at the transcriptional level. Ligand blot analysis of conditioned media using 1251-IGF-II revealed that CLA slightly decreased IGFBP-2 levels and increased IGFBP-4 levels. We confirmed our previous results that CLA inhibited cell growth in a dose-dependent manner but LA slightly increased cell growth. Exogenous IGF-II mitigated the growth inhibitory effect of CLA. These results indicate that the growth inhibitory effect of CLA may be at least in part mediated by decreasing IGF-II and IGFBP-2 secretion and increasing IGFBP-4 secretion in Caco-2 cells.