• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.5
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• pp.663-670
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• 2008

The effect of supplementing the diet of grazing dairy cows with fish oil (FO) and linseed oil (LSO) on milk conjugated linoleic acid (CLA) was investigated. Sixteen Holstein cows (17019 DIM) were assigned into two groups and fed a grain supplement (8.0 kg/d; DM basis) containing 800 g of saturated animal fat (CONT) or 200 g FO and 600 g LSO (FOLSO). All cows grazed together on Sudan grass pasture ad libitum and were fed the treatment diets for 3 wks. Cows were milked twice a day and milk samples were collected during the last three days of the trial. Milk production (24.89 and 22.45 kg/d), milk protein percentage (2.76 and 2.82) and milk protein yield (0.68 and 0.64 kg/d) for the CONT and FOLSO diets, respectively, were not affected (p>0.05) by treatment diets. Milk fat percentage (3.90 and 2.86) and milk fat yield (0.97 and 0.64 kg/d) were lower (p<0.05) with the FOLSO diet compared with the CONT diet. The concentration and yield of milk cis-9 trans-11 CLA were higher (p<0.05) with the FOLSO diet (2.56% of total FA and 16.44 g/d, respectively) than the CONT diet (0.66% of total FA and 6.44 g/d, respectively). The concentrations of milk trans C18:1 and vaccenic acid (VA) were higher (p<0.05) with the FOLSO diet (13.53 and 7.48% of total FA, respectively) than the CONT diet (3.69 and 2.27% of total FA, respectively). In conclusion, supplementing the diet of grazing cows with FO and LSO increased milk cis-9 trans-11 CLA content but reduced milk fat content and yield.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.11
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• pp.1521-1530
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• 2009

A metabolic study was conducted with four ruminally-cannulated lactating goats (Saanen, 29 weeks lactation, 65${\pm}$5 kg) in a 4${\times}$4 Latin square design with 4 dietary treatments. The goats were fed a basal mixed diet consisting of 80% concentrate and 20% chopped rye grass hay (DM basis, CON). The goats were also fed the CON diet supplemented with soybean oil at a 5% level of the concentrate (SO), the SO diet supplemented with 0.5% of sodium bicarbonate (SO-B) or the SO-B diet supplemented with 30 ppm monensin (SO-BM). The goats were housed in individual pen and the study was conducted for 8 weeks. An increased molar proportion of propionate (C3) was observed at 1 h (p<0.003) and 6 h (p<0.029) post-feeding from all the supplemented diets. Calculated methane emission was markedly decreased prior to morning feeding (p<0.01), and at 1 h (p<0.05) and 6 h post-feeding (p<0.05) in goats fed the supplemented diets. All the supplements increased (p<0.0001) cis9, trans11-CLA content in rumen fluid. Concentrations of both cis9, trans11-CLA (p<0.0001) and trans10, cis12-CLA (p<0.026) were also increased in the milk fat of lactating goats fed the supplemented diets. The SO-B and SO-BM diets further increased CLA content in goat milk compared to the SO diet. All supplements increased unsaturated (UFA, p<0.002), monounsaturated (MUFA, p<0.002) and polyunsaturated fatty acids (p<0.014) and reduced SFA to UFA ratio (p<0.023). The concentration of MUFA was even greater (p<0.002) for SO-BM than for the SO-B diet. In conclusion, feeding soybean oil (5% of concentrate) to lactating goats was a useful way to improve milk fat and to improve fatty acid profile in the milk by increasing potentially healthy fatty acids such as CLA. Supplementation of sodium bicarbonate or sodium bicarbonate with monensin to the soybean oil-based diet increased CLA content further in goat milk. Supplementation of soybean oil may be an effective method to reduce methane emission in lactating goats.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.12
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• pp.1728-1735
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• 2008

The present study was conducted with four ruminally canulated Holstein cows to observe the effects of monensin or fish oil on diet fermentation and production of conjugated linoleic acids (CLAs) in the rumen when fed diets supplemented with soybean oil and sodium bicarbonate. Cows of the control treatment were fed a basal diet (CON) consisting of 60% commercial concentrate and 40% chopped rye grass hay. Cows of other treatments were fed the same diet as CON, but the concentrate was supplemented with 7% of soybean oil and 0.5% of sodium bicarbonate (SO-B), SO-B supplemented with monensin (30 ppm, SO-BM) or concentrate supplemented with 6.3% of soybean oil, 0.5% of sodium-bicarbonate, 30 ppm of monensin and 0.7% of fish oil (SO-BMF). Dry matter (DM) intake of the cows was significantly (p<0.011) reduced by feeding the SO-BMF diet compared to the other diets which did not differ in DM intake. Whole tract digestibility of major dietary components was significantly (p<0.004-0.027) higher for SO-BMF than the other supplement-containing diets. Dietary supplements did not clearly affect rumen pH and ammonia concentrations compared to the CON diet. Significantly reduced (p<0.05) total VFA concentration was obtained by the addition of fish oil to the diet (SO-BMF) compared to other diets. No differences, however, were obtained in major VFA proportions as well as in total VFA between the supplemented diets. The SO-BM diet increased (p<0.01-0.05) the concentrations of trans-11 $C_{18:1}$ and linoleic acid in rumen fluid. Total CLA concentration was also increased by the feeding of SO-B and SO-BM diets during early fermentation times (up to 3 h) post-feeding. Cis-9, trans-11 CLA concentration in rumen fluid was highest (p<0.05) for SO-B up to 1 h while the highest (p<0.01) value for SO-BM occurred at 3 h post-feeding. An increased trans-10, cis-12 CLA concentration was obtained from the SO-B and SO-BM diets at 1 and 3 h post feeding compared to the other diets. Supplementation of oils with monensin and sodium bicarbonate increased (p<0.05) the proportions of $C_{18:1}$ and CLA in the plasma of cows, but the effect of monensin and/or fish oil was limited to trans-10, cis-12 CLA.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.4
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• pp.512-515
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• 2005

An in vitro study was conducted to determine the effect of C18-polyunsaturated fatty acid on direct incorporation into the rumen bacteria, bio-hydrogenation and production of CLA in vitro. Sixty milligrams of linoleic acid ($C_{18:2}$) or linolenic acid ($C_{18:3}$) were absorbed into the 0.5 g cellulose powder was added to the 150 ml culture solution consisting of 120 ml McDougall's buffer and 30 ml strained rumen fluid. Four uCi of 1-$^{14}C_{18:2}$ or 1-$^{14}C_{18:3}$ (1 uCi/15 mg each fatty acid) were also added to the corresponding fatty acids to estimate the direct incorporation into the bacterial lipids. The culture solution was then incubated anaerobically in a culture jar with stirrer at 39$^{\circ}C$ for 12 h. Ammonia concentration and pH of the culture solution were slightly influenced by the fatty acids. Amount of fatty acid incorporated into the bacteria was 1.20 mg and 0.43 mg/30 ml rumen fluid for $C_{18:2}$ and $C_{18:3}$, respectively during 12 h incubation. Slightly increased CLA (sum of cis-9, trans-11 and cis-10, trans-12 $C_{18:2}$) was obtained from the $C_{18:3}$ addition compared to that from $C_{18:2}$ after 12 h incubation in vitro.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.5
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• pp.648-652
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• 2012

This study was conducted to determine the effects of dietary addition of tea saponins (TS) and soybean oil (SO) on fatty acid profile and gene expression of stearoyl-CoA desaturase (SCD) in longissimus dorsi (LD) muscle of growing lambs. Thirty-two Huzhou lambs were assigned to four dietary treatments in a $2{\times}2$ factorial arrangement with main effects of TS (0 or 3 g/d) and SO (0 or 30 g/kg of diet DM). The diet without additives was considered as NTNS (no TS or SO). After a feeding trial for 60 d, four lambs of each treatment were slaughtered to collect the samples of LD muscle. Percentage of trans-11 vaccenic acid was enhanced (p<0.05) in muscle of lambs fed TS and SO. The proportion of total conjugated linoleic acid (CLA) was increased (p<0.05) by SO, but decreased (p<0.05) by TS in LD muscle. The percentage of total saturated fatty acids in muscle was decreased (p<0.05) by addition of TS and SO, while addition of SO increased (p<0.05) the percentage of total polyunsaturated fatty acids. The ratio of cis-9, trans-11 CLA to tran-11 vaccenic acid was decreased (p<0.05) by TS, but increased (p<0.05) by SO. The same effects were observed in SCD mRNA expression. From these results it is indicated that including TS and SO in the diet of growing lambs affect the fatty acid profiles of LD muscle and that the proportion of cis-9, trans-11 CLA in the muscle influenced by TS and SO may be related to the SCD gene expression.

• Korean Journal of Microbiology
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• v.51 no.3
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• pp.231-240
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• 2015

In this study, a total of 16 conjugated linoleic acid (CLA) producing lactic acid bacteria (LAB) were isolated from fermented foods. Among those strains, the S48 and P1201 strains were capable of producing higher CLA contents than other LABs. The two strains were classified as Lactobacillus plantarum based on morphological, physiological, chemotaxonomic, and molecular-genetic properties. The survival rates of these strain appeared to be 59.57% and 62.22% under artificial gastric conditions after 4 h at pH 2.5, respectively. These strains produced the cis-9, trans-11, and trans-10, cis-12 CLA isomers from 8% skim milk medium supplemented with the different free LA concentration at $37^{\circ}C$ for 48 h and the production of two CLA isomers constantly increased in the growth until 48 h of incubation. After 48 h of fermentation, the levels of CLA appeared highest in steamed soy-powder milk than fresh and roasted soy-powder milks. In particular, the CLA contents were produced $183.57{\mu}g/ml$ and $198.72{\mu}g/ml$ from steamed soy-powder milk after fermentation (48 h) with S48 and P1201 strains, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.6
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• pp.800-809
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• 2011

The objective of this study was to investigate the effects of different ratios of corn silage (CS): alfalfa hay (AH), and extruded soybeans (ESB) on milk yield, milk composition, blood metabolites, and fatty acids in milk fat and plasma. Ninety multiparous Holstein cows were arranged in a randomized block design experiment which lasted 14 weeks. Treatments were arranged as a $3{\times}3$ factorial with 0%, 5% or 10% ESB (dry matter basis) and three forage treatments: I) 30% CS, 10% AH and 10% Leymus chinense hay (LC); ii) 20% corn silage, 20% alfalfa hay and 10% LC; iii) 10% CS, 30% AH and 10% LC. Cows were allowed to consume a total mixed ration ad libitum. There was no change of dry matter intake when cows were fed the experimental diets. As more AH was added to the diets, milk yield, milk protein content and yield, and trans9, cis11-conjugated linoleic acids (CLA) concentrations in milk fat and plasma increased. When ESB were supplemented to the diets, milk yield, and trans9, cis11-CLA concentration in milk fat and plasma increased. When 10% ESB was added to the diet containing 30% AH the trans9, cis11-CLA content (1.46 g/100 g of total fatty acids) in milk was the highest among all treatments. These results suggests that AH could replace part of a CS diet and be a good forage source of diet for dairy cows to improve milk yield and milk composition. Meanwhile, ESB could be included in the diet with high AH to improve production performance of dairy cows.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.11
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• pp.1504-1512
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• 2009

A feeding trial was conducted to examine the effect of high-temperature-micro-time (HTMT) processing of diets containing extruded soybean (ESB) in high quantity on milk fat production, metabolic responses, and the formation of conjugated linoleic acid (CLA) and trans-vaccenic acid (TVA). Twenty-one multiparous Holstein cows in mid-lactation were blocked according to milk yield in the previous lactation. Cows within each block were randomly assigned to either normal concentrate or HTMT treated diets containing ESB (7.5% HTMT-ESB and 15% HTMT-ESB). It was hypothesized that the HTMT-ESB would affect the undegradable fatty acids in the rumen and, thus, would modify the fatty acid profile of milk fat. Both 7.5% and 15% HTMT-ESB did not affect milk yield, fat, protein, lactose and solid-not-fat (SNF), but the proportion of cis-9, trans-11 CLA in milk fat was significantly increased by these treatments. Content of TVA in milk fat was not affected by HTMT-ESB. The HTMT-ESB influenced the fatty acid profile in milk fat, but there was little difference between 7.5% and 15% of supplementation. HTMT-ESB feeding significantly decreased the concentration of plasma insulin and glucose, while plasma growth hormone (GH), triglyceride (TG), non-esterified fatty acid (NEFA) and HDLcholesterol were increased by 7.5% and 15% ESB-HTMT supplementation in comparison to the control group (p<0.05). However, no significant difference was observed in plasma LDL-cholesterol, insulin like growth factor (IGF)-1, T3, T4, and leptin concentrations among treatments (p>0.05). The present results showed that cis-9, trans-11 CLA production was increased by HTMT treatment of dietary ESB without reduction of milk fat, and the unchanged milk fat and yield was assumed to be associated with the constant level of thyroid hormones, leptin, and IGF-1.