• Journal of the Korean Society of Food Science and Nutrition
• /
• v.20 no.4
• /
• pp.401-407
• /
• 1991

Anticarcinogenic conjugated dienoic derivatives of linoleic acid (CLA) is present in grilled beef, cheese, and related foods, CLA is generated via isomerization of linoleic acid in the cow's rumen by anaerobic bacteria and food proceessing as well. Another source of CLA is its endogenous generation via the carbon centered free radical oxdation of linoleic acid. We propose that the formation and generation of CLA in vivo represents a previously unrecognized in situ "defense mechanism" against membrane attack by oxygen free radicals. The cis, 9-trans, 11 CLS isomer is selectively incorporated into cellular phospholipid, which exhibits a potent antioxidant, reduces the activation of 2-amino-3-methylimidazo, [4,5-f] quinoline (IQ) for baxterial mutagenesis, and inhibits ornithine decarboxylase(ODC) activity induced by 12-0-tetradecanoylphorbol-13-acetate (TPA). We believe that at least these biological activities of CLA explain the anticarcinogenic activity of CLA.

• Korean Journal of Food Science and Technology
• /
• v.31 no.6
• /
• pp.1453-1457
• /
• 1999

The optimal conditions of alkali isomerization to obtain conjugated linoleic acid (CLA) concentrate from vegetable oils which have antioxidant and anticarcinogenic properties were studied. The result of alkali isomerization of various vegetable oils indicated that CLA content of safflower oil which contains more linoleic acid than any other vegetable oils was the highest of all experimental vegetable oils. During alkali isomerization, the amount of cis-9, trans-11 CLA and total CLA content in safflower oil was the highest at $8{\sim}11%$ KOH concentration and $180{\sim}185^{\circ}C$. But heating time had no effect on CLA formation after $20{\sim}40$ minutes. As a result of alkali isomerization of neutral lipid, glycolipid and phospholipid in safflower oil, CLA content of neutral lipid class was higher than any other lipid classes. By urea treatment and HPLC fractionation, total CLA content in alkali-isomerized safflower oil increased to 95.4% from 78.9%.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.9
• /
• pp.1271-1277
• /
• 2008

The effects of feeding soybean oil (SBO) or rumen protected conjugated linoleic acid (RP-CLA) on CLA accumulation in milk, and performance of lactating dairy cows were studied. Twenty four Holstein Friesian crossbred lactating dairy cows, averaging $126{\pm}45days$ in milk, $15.6{\pm}2.43kg$ of milk and $452{\pm}51kg$ body weight were stratified randomly and assigned in a randomized complete block design (RCBD) to three treatments of 8 cows each. The treatments were control, 150 g of SBO and 150 g of RP-CLA supplementation. Performance parameters showed that DM intake, NELP intake and body weight change were similar across treatments, while CP intake was decreased by SBO and RP-CLA supplementation. Milk yield and milk composition were not significantly different among treatments, except for milk fat percentage and fat yield which were significantly decreased by 27% (p<0.05) and by 28% (p<0.01), respectively, by RP-CLA supplements compared with control treatment. Feeding RP-CLA reduced 3.5% FCM compared with the other treatments (p<0.003). Both SBO and RP-CLA supplementation reduced ${\geq}C18:0$ and CLA concentration in milk fat.

• Journal of Life Science
• /
• v.27 no.8
• /
• pp.965-973
• /
• 2017

Conjugated linoleic acid (CLA) is a group of positional and geometric isomers of linoleic acid with conjugated double bonds at C9,C11 and C10,C12 positions. Of possible CLA isomers, a naturally occurring CLA isomer is c9,t11-CLA which is produced from linoleic acid by linoleate isomerase from various rumen and lactic bacteria, and mushroom mycelia. Meanwhile, synthetically prepared CLA contained an equal amount of c9,t11-CLA and t10,c12-CLA isomers, and other isomers as minor constituents. CLA was firstly mentioned in 1939 during the elaidinization reaction of linoleic acid. Thereafter, CLA was not an attractant to scientists because it was not scientifically interested any more. However, since the anticarcinogenic action was driven from 7,12-dimethylbenz[a]anthracene (DMBA)-induced mouse skin carcinogenesis in 1987, CLA-related researches were drastically elevated, resulting in approximately 6,100 research papers in literature, so far. CLA exhibited the significant biological activities: anticarcinogenic, antidiabetic, antihypertensive, antiatherosclerotic, body-fat reducing, antioxidative, antiinflammatory, testosterone producing and other activities. Interestingly, two major CLA isomers, c9,t11-CLA and t10,c12-CLA, exhibited different biological activities. Meanwhile, t,t-CLA isomers which is minor constituent of chemically synthesized CLA from linoleic acid exhibited more potent anticarcinogenic activity in carcinogen-induced animal models and cancer cell lines than other CLA isomrs. In the present review, the significant biological activities of CLA were discussed along with historical studies of CLA since 1939.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.26 no.5
• /
• pp.972-977
• /
• 1997

Conjugated dienoic derivatives of linoleic acid(CLA) are a series of positional and gemotric isomers of linoleic acid which are found naturally in food, mainly dietary products and breef. We studied the effects of CLA on the growth of tumor cells and the production of interleukin-1(IL-1) and interleukin-2(IL-2). CLA treatment markedly inhibited the growth of Yac-1 cells and sarcoma-180 cells by 99 and 82% to that of control, respectively, after four days of incubation at 37$^{\circ}C$. To elucidate the immunological mechanism of antitumor activity of CLA, spleen cells of Balb/c mouse were exposed to 31, 63, 125, 250 $\mu\textrm{g}$ of CLA per ml for 24 hrs at 37$^{\circ}C$. The culture supernatants of CLA-exposed spleen cells reduced the production of IL-1 and IL-2 in all of the test conditions. These results indicate that the anticarcino-genic effect of CLA was mediated by the other actions rather than the production of the Il-1 or IL-2. We suggest that CLA might have an antiinflammatory effect in part due to its inhibitory action on the production of IL-1.

• Food Science and Biotechnology
• /
• v.18 no.3
• /
• pp.586-593
• /
• 2009

Since conjugated linoleic acid (CLA) was identified as a principal anticancer component from ground beef in the 1980s, CLA research has discovered that CLA has a wide range of biologically beneficial effects. Clinical studies with CLA are on the rise, and it is apparent that CLA may not be as effective in humans as in rodents, in particular its anti-obesity aspect. In addition, research with regard to other conjugated fatty acids as well as CLA metabolites is still in its infancy. Investigation of bioactivities for other conjugated fatty acids and CLA metabolites may help to extend the understanding of CLA and its mechanisms of actions. This may pose an opportunity to use CLA more efficiently and expand the future use of other conjugated fatty acids as pharmacological agents to assist current treatments.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.29 no.3
• /
• pp.389-394
• /
• 2000

CLA의 glycerol 유도체를 화학적으로 합성하였다. CLA-Cl(1.79 mmole), glycerol(0.6 mmole)과 pyridine (1.3mL)를 25C에서 8시간 반응시켰다. 이 반응물을 SGCC와 TLC를 이용하여 CLA의 glycerol 유도체를 분리하고 1H-NMR, 13C-NMR, IR, MS를 이용하여 분리된 유도체를 동정하였다. 이 실험조건하에서 사용된 CLA의 59.4%가 CLA의 glycerol 유도체(CLA-TG, CLA-DG, CLA-MG)로 전환되었다. CLA의 glycerol 유도체 중 CLA-TG는 52.1%, CLA-DG는 17.0%, CLA-MG는 30.9%였다.

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

• Journal of Animal Science and Technology
• /
• v.48 no.1
• /
• pp.107-114
• /
• 2006

A total of 180 Arbor Acre broilers (35 days of age) were fed a diet containing 0%, 0.6%, 1.2%, 1.8%, 2.4% or 4.8% conjugated linoleic acid (CLA) for 3 weeks then slaughtered at week 1, 2 and 3. Thigh and breast muscles were seamed out, vaccum-packed prior to storage in a chill for days 7 to analyse thiobarbituric acid reactive substances (TBARS). The accumulation of CLA in breast and thigh muscles was increased significantly (P<0.05) as the CLA level was increased, but no significant difference amongst the treatments. The contents of saturated fatty acids were significantly increased(P<0.05) with an increase of dietary CLA level, but those of unsaturated fatty acids were significantly decreased (P<0.05). The content of mono unsaturated fatty acid (MUFA) was decreased as dietary CLA level increased, even though that of poly unsaturated fatty acid (PUFA) had a little difference between dietary CLA level. Dietary CLA reduced the degree of lipid oxidation in raw chicken meat during storage.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2001.11a
• /
• pp.52-53
• /
• 2001

The dietary effects of conjugated linoleic acid (CLA) on lipid concentrations and fatty acid composition of various tissues were studied in young chicks. Chicks were fed one of four diets containing 6% tallow (TO), 4% TO-2% CLA, 2% TO-4% CLA or 6% CLA for 3wks. There were no differences in growth performances, but relative liver weight in chicks fed dietary CLA up to 4% was significantly higher than that of 6% TO group. The concentrations of various lipid fractions in serum were not affected by CLA feeding. With the increase in dietary CLA levels, total CLA in liver and leg muscle increased linearly.