scholarly journals CONJUGATED LINOLEIC ACID AND CANCER IN HUMANS-IS THERE A ROLE OR NOT? A REVIEW OF THE SCIENTIFIC EVIDENCE

10.37512/300 ◽  
2019 ◽  
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Clinical Studies ◽  
Unsaturated Fatty Acids ◽  
Scientific Evidence ◽  
Epidemiological Studies ◽  
Ruminal Bacteria ◽  
Butyrivibrio Fibrisolvens ◽  
Gender Diverse ◽  
And Gender

Conjugated linoleic acids are naturally occurring fatty acids that are found predominantly in ruminant meat, milk and dairy products. They are composed mainly of two isomers: cis-9, trans-11 and trans-10, cis-12 fatty acid. Their synthesis occurs mainly by the action of ruminal bacteria, Butyrivibrio Fibrisolvens, and a host of lactic acid bacteria, which isomerize linoleic acid to CLA or by synthesis via α9-desaturase of 11-trans octadecanoic acid, and, through desaturation of free linoleic acid or other unsaturated fatty acids. Although cis-9, trans-11 and trans-9, trans-11 CLA isomers have consistently shown anti-carcinogenicity on animal models and on cancerous human cells, results from clinical trials are inconclusive and conflicting. Despite most of the data on humans being mainly from epidemiological studies, a few clinical studies with breast and colorectal cancer sufferers have shown some promise. Controlled, long-term, racial and gender diverse, geographically spread clinical studies are required to understand the link between CLA intake and incidence of human cancers.

scholarly journals Metabolism of conjugated linoleic acids and 18 : 1 fatty acids by ruminal bacteria: products and mechanisms

Microbiology ◽  
2010 ◽  
Vol 156 (2) ◽  
pp. 579-588 ◽  
Author(s):  
Nest McKain ◽  
Kevin J. Shingfield ◽  
R. John Wallace
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Unsaturated Fatty Acids ◽  
Deuterium Oxide ◽  
Geometric Isomers ◽  
Conjugated Linoleic Acids ◽  
Ruminal Bacteria ◽  
Butyrivibrio Fibrisolvens ◽  
Cla Isomers ◽  
Deuterium Enrichment

Cultures of ruminal bacteria known to metabolize unsaturated fatty acids were grown in medium containing 50 μg ml−1 of geometric and positional isomers of conjugated linoleic acid (CLA) or 18 : 1 fatty acids and 37.4 % deuterium oxide to investigate the mechanisms responsible for fatty acid metabolism. Butyrivibrio fibrisolvens JW11 converted cis-9,trans-11-18 : 2 and trans-9,trans-11-18 : 2 to trans-11-18 : 1 as the main product, labelled at C-9, and metabolized trans-10,cis-12-18 : 2 to trans-10-18 : 1, labelled at C-13, and smaller amounts of trans-12-18 : 1 and cis-12-18 : 1. Butyrivibrio proteoclasticus P-18 did not grow in the presence of cis-9,trans-11-18 : 2 or trans-10,cis-12-18 : 2, but grew in medium containing trans-9,trans-11-18 : 2, forming 18 : 0. Propionibacterium acnes, a ruminal species that isomerizes linoleic acid to trans-10,cis-12-18 : 2, did not metabolize CLA isomers further. B. fibrisolvens metabolized small amounts of trans-10-18 : 1, trans-11-18 : 1 and cis-9-18 : 1, but the products formed were not detected. B. proteoclasticus, on the other hand, carried out substantial conversion of 18 : 1 substrates to 18 : 0. P. acnes hydrated cis-9-18 : 1 and trans-11-18 : 1 to 10-OH-18 : 0, which was further oxidized to yield 10-O-18 : 0. The deuterium enrichment in the intermediates formed during incubations with 9,11 geometric isomers of CLA was about half that of the products from trans-10,cis-12 CLA and 18 : 1 isomers, suggesting that the reduction of 9,11 geometric isomers CLA by ruminal bacteria occurs via different mechanisms compared with the metabolism of other unsaturated fatty acids.

scholarly journals Influence of fish oil on ruminal biohydrogenation of C18 unsaturated fatty acids

2006 ◽  
Vol 95 (6) ◽  
pp. 1199-1211 ◽  
Author(s):  
I. Wąsowska ◽  
M. R. G. Maia ◽  
K. M. Niedźwiedzka ◽  
M. Czauderna ◽  
J. M. C. Ramalho Ribeiro ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Fish Oil ◽  
Unsaturated Fatty Acids ◽  
Butyrivibrio Fibrisolvens ◽  
Isomerase Activity ◽  
Epa And Dha ◽  
Pure Cultures ◽  
Ruminal Biohydrogenation

Dietarycis-9,trans-11-conjugated linoleic acid (CLA) is generally thought to be beneficial for human health. Fish oil added to ruminant diets increases the CLA concentration of milk and meat, an increase thought to arise from alterations in ruminal biohydrogenation of unsaturated fatty acids. To investigate the mechanism for this effect,in vitroincubations were carried out with ruminal digesta and the main biohydrogenating ruminal bacterium,Butyrivibrio fibrisolvens. Linoleic acid (LA) or α-linolenic acid (LNA) was incubated (1·67g/l) with strained ruminal digesta from sheep receiving a 50:50 grass hay–concentrate ration. Adding fish oil (up to 4·17g/l) tended to decrease the initial rate of LA (P=0·025) and LNA (P=0·137) disappearance, decreased (P<0·05) the transient accumulation of conjugated isomers of both fatty acids, and increased (P<0·05) the accumulation oftrans-11-18:1. Concentrations of EPA (20:5n-3) or DHA (22:6n-3), the major fatty acids in fish oil, were low (100mg/l or less) after incubation of fish oil with ruminal digesta. Addition of EPA or DHA (50mg/l) to pure cultures inhibited the growth and isomerase activity ofB. fibrisolvens, while fish oil had no effect. In contrast, similar concentrations of EPA and DHA had no effect on biohydrogenation of LA by mixed digesta, while the addition of LA prevented metabolism of EPA and DHA. Neither EPA nor DHA was metabolised byB. fibrisolvensin pure culture. Thus, fish oil inhibits ruminal biohydrogenation by a mechanism which can be interpreted partly, but not entirely, in terms of its effects onB. fibrisolvens.

scholarly journals Explore the gene network regulating the composition of fatty acids in cottonseed

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lihong Ma ◽  
Xinqi Cheng ◽  
Chuan Wang ◽  
Xinyu Zhang ◽  
Fei Xue ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Linolenic Acid ◽  
Gene Network ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Accumulation Pattern ◽  
Time Points ◽  
Expression Characteristics

Abstract Background Cottonseed is one of the major sources of vegetable oil. Analysis of the dynamic changes of fatty acid components and the genes regulating the composition of fatty acids of cottonseed oil is of great significance for understanding the biological processes underlying biosynthesis of fatty acids and for genetic improving the oil nutritional qualities. Results In this study, we investigated the dynamic relationship of 13 fatty acid components at 12 developmental time points of cottonseed (Gossypium hirsutum L.) and generated cottonseed transcriptome of the 12 time points. At 5–15 day post anthesis (DPA), the contents of polyunsaturated linolenic acid (C18:3n-3) and saturated stearic acid (C18:0) were higher, while linoleic acid (C18:2n-6) was mainly synthesized after 15 DPA. Using 5 DPA as a reference, 15,647 non-redundant differentially expressed genes were identified in 10–60 DPA cottonseed. Co-expression gene network analysis identified six modules containing 3275 genes significantly associated with middle-late seed developmental stages and enriched with genes related to the linoleic acid metabolic pathway and α-linolenic acid metabolism. Genes (Gh_D03G0588 and Gh_A02G1788) encoding stearoyl-ACP desaturase were identified as hub genes and significantly up-regulated at 25 DPA. They seemed to play a decisive role in determining the ratio of saturated fatty acids to unsaturated fatty acids. FAD2 genes (Gh_A13G1850 and Gh_D13G2238) were highly expressed at 25–50 DPA, eventually leading to the high content of C18:2n-6 in cottonseed. The content of C18:3n-3 was significantly decreased from 5 DPA (7.44%) to 25 DPA (0.11%) and correlated with the expression characteristics of Gh_A09G0848 and Gh_D09G0870. Conclusions These results contribute to our understanding on the relationship between the accumulation pattern of fatty acid components and the expression characteristics of key genes involved in fatty acid biosynthesis during the entire period of cottonseed development.

scholarly journals Fatty acid positional distribution (sn-2 fatty acids) and phospholipid composition in Chinese breast milk from colostrum to mature stage

2018 ◽  
Vol 121 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Ke Wu ◽  
Runying Gao ◽  
Fang Tian ◽  
Yingyi Mao ◽  
Bei Wang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Fatty Acid Profile ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Content ◽  
Positional Distribution ◽  
Phospholipid Composition ◽  
Mature Stage ◽  
Feeding Time

AbstractThis study quantified the fatty acid profile with emphasis on the stereo-specifically numbered (sn) 2 positional distribution in TAG and the composition of main phospholipids at different lactation stages. Colostrum milk (n 70), transitional milk (n 96) and mature milk (n 82) were obtained longitudinally from healthy lactating women in Shanghai. During lactation, total fatty acid content increased, with SFA dominating in fatty acid profile. A high ratio of n-6:n-3 PUFA was observed as 11:1 over lactation due to the abundance of linoleic acid in Chinese human milk. As the main SFA, palmitic acid showed absolute sn-2 selectivity, while oleic acid, linoleic acid and α-linolenic acid, the main unsaturated fatty acids, were primarily esterified at the sn-1 and sn-3 positions. Nervonic acid and C22 PUFA including DHA were more enriched in colostrum with an sn-2 positional preference. A total of three dominant phospholipids (phosphatidylethanolamine (PE), phosphatidylcholine (PC) and sphingomyelin (SM)) were analysed in the collected samples, and each showed a decline in amount over lactation. PC was the dominant compound followed by SM and PE. With prolonged breast-feeding time, percentage of PE in total phospholipids remained constant, but PC decreased, and SM increased. Results from this study indicated a lipid profile different from Western reports and may aid the development of future infant formula more suitable for Chinese babies.

scholarly journals Inhibition of steroid 5α-reductase by specific aliphatic unsaturated fatty acids

1992 ◽  
Vol 285 (2) ◽  
pp. 557-562 ◽  
Author(s):  
T Liang ◽  
S Liao
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Linoleic Acid ◽  
Linolenic Acid ◽  
Unsaturated Fatty Acids ◽  
Binding Assay ◽  
Reductase Activity ◽  
Undecylenic Acid ◽  
Gamma Linolenic Acid ◽  
Enzymic Assay

Human or rat microsomal 5 alpha-reductase activity, as measured by enzymic conversion of testosterone into 5 alpha-dihydrotestosterone or by binding of a competitive inhibitor, [3H]17 beta-NN-diethulcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([3H]4-MA) to the reductase, is inhibited by low concentrations (less than 10 microM) of certain polyunsaturated fatty acids. The relative inhibitory potencies of unsaturated fatty acids are, in decreasing order: gamma-linolenic acid greater than cis-4,7,10,13,16,19-docosahexaenoic acid = cis-6,9,12,15-octatetraenoic acid = arachidonic acid = alpha-linolenic acid greater than linoleic acid greater than palmitoleic acid greater than oleic acid greater than myristoleic acid. Other unsaturated fatty acids such as undecylenic acid, erucic acid and nervonic acid, are inactive. The methyl esters and alcohol analogues of these compounds, glycerols, phospholipids, saturated fatty acids, retinoids and carotenes were inactive even at 0.2 mM. The results of the binding assay and the enzymic assay correlated well except for elaidic acid and linolelaidic acid, the trans isomers of oleic acid and linoleic acid respectively, which were much less active than their cis isomers in the binding assay but were as potent in the enzymic assay. gamma-Linolenic acid had no effect on the activities of two other rat liver microsomal enzymes: NADH:menadione reductase and glucuronosyl transferase. gamma-Linolenic acid, the most potent inhibitor tested, decreased the Vmax. and increased Km values of substrates, NADPH and testosterone, and promoted dissociation of [3H]4-MA from the microsomal reductase. gamma-Linolenic acid, but not the corresponding saturated fatty acid (stearic acid), inhibited the 5 alpha-reductase activity, but not the 17 beta-dehydrogenase activity, of human prostate cancer cells in culture. These results suggest that unsaturated fatty acids may play an important role in regulating androgen action in target cells.

scholarly journals Profile of ingested fatty acids and in the duodenal digest of steers fed different diets

2010 ◽  
Vol 39 (11) ◽  
pp. 2502-2511 ◽  
Author(s):  
Luís Fernando Glasenapp de Menezes ◽  
Gilberto Vilmar Kozloski ◽  
João Restle ◽  
Ivan Luiz Brondani ◽  
Raul Dirceu Pazdiora ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Latin Square ◽  
Tropical Pasture ◽  
Ruminal Fermentation ◽  
Omega 3 ◽  
Conventional Diet

It was evaluated in this study the effect of the type of the diet on duodenal flow of long-chain fatty acids in steers. The tested diets were the following: conventional (feedlot diet composed of 60% corn silage and 40% of concentrate); winter forage silage - rye grass (Lolium multiflorum, Lam); or tropical forage silage - association of millet (Pennisetum americanum, Leeke + alexander grass, Brachiaria plantaginea). Six Charolais × Nellore crossbred steers with cannulas in duodenum were used in a 3 × 3 double Latin square. Dry material intake was similar among the groups (mean of 4,037 g/day), but the intake of total fatty acids and saturated fatty acids were higher in the group fed tropical pasture silage. On the other hand, the animals which received the conventional diet consumed higher quantity of unsaturated fatty acids. Tropical pasture silage provided higher consumption of vacenic acid (C18:1 t-11) and the winter forage silage offered higher consumption of conjugated linoleic acid. The intake of omega-6 fatty acids was higher in the group fed conventional diet and for omega-3, intake was higher in the group fed tropical pasture diet. The total fatty acid flow in the duodenum was not affected by the diets, but in all treatments it was higher than the consumed one. The animals fed diet with concentrate show the greatest changes on the profile of fatty acids during the ruminal fermentation. Conventional diets provide the highest intake of unsaturated fatty acids and the highest availability of vacenic acid in the small intestine, but they do not increase the supply of intestinal conjugated linoleic acid.

FATTY ACID COMPOSITION OF SERUM LIPIDS IN HYPER- AND HYPOTHYROIDISM

1972 ◽  
Vol 71 (1) ◽  
pp. 62-72 ◽  
Author(s):  
Knut Kirkeby
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Acid Composition ◽  
Serum Lipids ◽  
Unsaturated Fatty Acids ◽  
Eicosatrienoic Acid ◽  
High Linoleic Acid ◽  
Absolute Concentrations

ABSTRACT The fatty acid composition of cholesterol esters, phospholipids, and triglycerides of the serum has been studied in groups of hyperthyroid and hypothyroid women and also in control material matched for age. In hyperthyroidism, a decrease in the proportions of linoleic acid and an increase in the proportions of some saturated and mono-unsaturated fatty acids were observed. When absolute concentrations were considered, it appeared that the decrease in linoleic acid was almost equivalent to the entire decrease in total fatty acids in the serum of the hyperthyroid patients. In hypothyroidism no changes were noted in the proportions of linoleic, saturated and mono-unsaturated fatty acids, and the absolute concentrations reflected the general increase in serum lipids. It is believed that these findings may be explained by the changes in lipid turnover which are known to occur in disturbances of thyroid function. In hyperthyroidism, they lead to a linoleic acid deficiency, while a sparing effect must be operating in hypothyroidism. The finding of relatively high linoleic acid values combined with hyperlipaemia in hypothyroidism seems to be characteristic of the condition, since other types of hyperlipaemia are almost invariably combined with low percentages of linoleic acid. Results regarding arachidonic and eicosatrienoic acid are consistent with increased synthesis in hyperthyroidism, and decreased synthesis in hypothyroidism.

Effect of animal age and gender on fatty acid and elemental composition in Austrian beef applicable for authentication purposes

2013 ◽  
Vol 67 (3) ◽  
Author(s):  
Adriána Bednárová ◽  
Ján Mocák ◽  
Walter Gössler ◽  
Margit Velik ◽  
Josef Kaufmann ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Elemental Composition ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Fatty Acid Content ◽  
Principal Component ◽  
Omega 3 ◽  
Age And Gender ◽  
And Gender

AbstractThe main aim of the present study was to find differences in the content of fatty acids and variations in elemental composition in beef samples of longissimus dorsi muscle related to cattle age and gender. A further goal was to describe interrelations among the selected variables (descriptors) characterising the samples. For this purpose, an extensive data table was compiled, which contains chemical descriptors specifying forty-six beef samples originating from four well-known Austrian grassland-based beef labels. The following descriptors were investigated: (a) concentrations of 33 fatty acids, (b) concentrations of 19 elements, (c) contents of dry-mass, protein, intramuscular fat, and ash, (d) total content of saturated fatty acids (SFA), mono-unsaturated fatty acids (MUFA), and poly-unsaturated fatty acids (PUFA), (e) total contents of omega-3 (n-3) and omega-6 (n-6) PUFA and their ratio. The correlation analysis provided a number of statistically significant correlations among the descriptors, which were concordant with the results of the principal component analysis and cluster analysis. Furthermore, the effect of age and gender of cattle (both acting as target factors) on the fatty acid content and elemental composition of beef was examined by analysis of variance (ANOVA) and appropriate non-parametric tests. Several important interrelations among the beef characteristics investigated were also discovered. Finally, the most relevant beef descriptors were utilised in linear discrimination analysis (LDA) for predicting the slaughter age of the cattle for beef authentication.

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