Potential regulation of linoleic acid and volatile organic compound contents in meat of chickens by PLCD1

Omega-3(linolenic acid(ALA),docosapentaenoic acid,eicosapentaenoic acid)and omega-6(linoleic acid(LA),arachidonic acid)polyunsaturated fatty acids are essential for health and normal physiological functioning in humans.Here we report a genome-wide association study(GWAS)on LA content in chicken meat.The 19 significant single nucleotide polymorphisms(SNPs)identified by the GWAS approach were annotated in VILL,PLCD1 and OXSR1 genes with highly polymorphic linkage blocks,and explained 4.5%of the phenotypic variation in the LA content.Specifically,the PLCD1 mRNA expression level was negatively correlated with the LA content,and significantly higher in chickens with low LA content than in those with high LA content.In addition,PLCD1 was found to be involved in metabolic pathways,etc.Furthermore,the LA content was correlated with volatile organic compounds(e.g.,octanal,etc.),but no relationship was found with intramuscular fat and triglycerides in chicken meat.The results indicated that there are key SNPs in PLCD1 that regulate the content of LA,and it has no significant effect on fat deposition,but may affect the content of volatile organic compounds(VOCs).

Transcriptome-based analysis of key genes and pathways affecting the linoleic acid content in chickens

Linoleic acid is an essential polyunsaturated fatty acid that cannot be synthesized by humans or animals themselves and can only be obtained externally.The amount of linoleic acid present has an impact on the quality and flavour of meat and indirectly affects consumer preference.However,the molecular mechanisms influencing the deposition of linoleic acid in organisms are not clear.As the molecular mechanisms of linoleic acid deposition are not well understood,to investigate the main effector genes affecting the linoleic acid content,this study aimed to screen for hub genes in slow-type yellow-feathered chickens by transcriptome sequencing(RNA-Seq)and weighted gene coexpression network analysis(WGCNA).We screened for candidate genes associated with the linoleic acid content in slow-type yellow-feathered broilers.A total of 399 Tiannong partridge chickens were slaughtered at 126 days of age,fatty acid levels were measured in pectoral muscle,and pectoral muscle tissue was collected for transcriptome sequencing.Transcriptome sequencing results were combined with phenotypes for WGCNA to screen for candidate genes.KEGG enrichment analysis was also performed on the genes that were significantly enriched in the modules with the highest correlation.A total of 13310 genes were identified after quality control of transcriptomic data from 399 pectoral muscle tissues.WGCNA was performed,and a total of 26 modules were obtained,eight of which were highly correlated with the linoleic acid content.Four key genes,namely,MDH2,ATP5B,RPL7A and PDGFRA,were screened according to the criteria|GS|>0.2 and|MM|>0.8.The functional enrichment results showed that the genes within the target modules were mainly enriched in metabolic pathways.In this study,a large-sample-size transcriptome analysis revealed that metabolic pathways play an important role in the regulation of the linoleic acid content in Tiannong partridge chickens,and MDH2,ATP5B,RPL7A and PDGFRA were screened as important candidate genes affecting the linoleic acid content.The results of this study provide a theoretical basis for selecting molecular markers and comprehensively understanding the molecular mechanism affecting the linoleic acid content in muscle,providing an important reference for the breeding of slow-type yellowfeathered broiler chickens.

A Study on Anti-oxidative Activity of Soybean Peptideswith Linoleic Acid Peroxidation Systems

Soybean bioactive peptides（SBPs） were prepared from the isolated soybean protein by proteolysis with an alkaline protease, alcalase, at 50℃ and pH = 8.0. The dependence of hydrolysis time on hydrolysis degree and molecular weight distribution were examined. The hydrolysate was fractionated on a Sephadex G-25 column and the anti-oxidative activities of the fractions were detected by the method of pyrogallol auto-oxidation. The average chain length of soybean peptides that have anti-oxidative activity was estimated to be about 7. The anti-oxidative properties of the soy- bean peptide were also studied by using linoleic acid peroxidation systems. The optimal condition of the peroxidation system was set up, Vc/Cu^2 ＋ as the inducer at pH = 7.4 and 25 ℃. In addition, soybean peptides show higher antioxidative activity compared with GSH.

Linoleic acid metabolic pathway allows for an efficient increase of intramuscular fat content in pigs

Background: Intramuscular fat(IMF) content is a relevant trait for high-quality meat products such as dry-cured ham,but increasing IMF has the undesirable correlated effect of decreasing lean growth.Thus,there is a need to find selection criteria for IMF independent from lean growth.In pigs,the proportion of linoleic(C18:2) and arachidonic(C20:4) acids decline with fat deposition and therefore they can be considered as indicators of fatness.The aim of this research was to estimate the genetic variation for C18:2 and C20:4 in IMF and their genetic correlations with IMF and lean growth traits,with the objective to assess their potential as specific biomarkers of IMF.The analysis was conducted using a full-pedigreed Duroc resource line with 91,448 records of body weight and backfat thickness(BT) at 180 days of age and 1371 records of fatty acid composition in the muscle gluteus medius.Results: The heritability estimates for C18:2 and C20:4 in IMF,whether expressed in absolute(mg/g of muscle) or in relative(mg/g of fatty acid) terms,as well as for their ratio(C20:4/C18:2),were high(> 0.40),revealing that the C18:2 to C20:4 pathway is subjected to substantial genetic influence.Litter effects were not negligible,with values ranging from8% to 15% of the phenotypic variance.The genetic correlations of C18:2 and C20:4 with IMF and BT were negative(-0.75 to-0.66,for IMF,and-0.64 to-0.36,for BT),if expressed in relative values,but almost null(-0.04 to 0.07),if expressed in absolute values,except for C18:2 with IMF,which was highly positive(0.88).The ratio of C20:4 to C18:2 also displayed a stronger genetic correlation with IMF(-0.59) than with BT(-0.10).Conclusions: The amount of C18:2 in muscle can be used as an IMF-specific biomarker.Selection for the absolute amount of C18:2 is expected to deliver a similar response outcome as selection for IMF at restrained BT.Further genetic analysis of the C18:2 metabolic pathway may provide new insights into differential fat deposition among adipose tissues and on candidate genes for molecular markers targeting specifically for one of them.

Differential effects of adulterated versus unadulterated forms of linoleic acid on cardiovascular health

According to the classic ＂diet-heart＂ hypothesis, high dietary intake of saturated fats and cholesterol combined with low intake of polyunsaturated fats can increase levels of serum cholesterol and lead to the development of atherogenic plaques and ultimately cardio- vascular diseases. Recently, the beneficial health effects of omega-6 polyunsaturated fatty acids, particularly linoleic acid （LA）, on cardiovascular health have been called into question with some scientists suggesting that consumption of LA should be reduced in Western countries. The focus of this critical review is on the controversy surrounding the effects of dietary intake of LA on cardiovascular health. Specifically, we critically examined the effects of both unadulterated and adulterated forms of LA on cardiovascular health outcomes based on findings from epidemiological studies and randomized controlled trials. Additionally, we address common concems surrounding dietary intake of LA regarding its relationship with arachidonic acid, the ratio of omega-6 to omega-3 fatty acids, and its relationship with inflammation. Our critical review indicates that unadulterated forms of LA are cardioprotective and should be consumed as part of a healthy diet. In contrast, abundant evidence now indicates that adulterated forms of LA, predominantly hydrogenated vegetable oils, are atherogenic and should not be considered part of a healthy diet. The ability to adulterate the natural omega-6 fatty acid, LA, has contributed to mixed findings regarding the effects of this fatty acid on cardiovascular health. Thus, it is critical that the source of LA be taken into account when drawing conclusions about the physiological effects of this fatty acid. The findings of the present review are in line with current dietary recommendations of the American Heart Association.

EFFECT OF CIS-9, TRANS-11-CONJUGATED LINOLEIC ACID ON CELL CYCLE OF MAMMARY ADENOCARCINOMA CELLS(MCF-7)

Objective: To determine the effect of cis-9, trans-1 1-conjugated linoleic acid on the cell cycle of mammary cancer cells (MCF-7) and the possible mechanism of the inhibitory effect of c9,t11-CLA. Methods: Using cell culture and immunocytochemical techniques, we examined the cell growth, DNA synthesis, expression of PCNA, cyclin A, B1, D1, p16ink4a and p21cip/waf1 of MCF-7 cells at various c9,t11-CLA concentrations (25μM, 50μM, 100μM and 200μM), at 24h and 48h. 96% ethand was used as negative control. Results: The cell growth and DNA synthesis of MCF-7 cells were inhibited by c9,t11-CLA. After treatment with various doses of c9,t11-CLA mentioned above for 8 days, the inhibition frequency was 27.18%, 35.43%, 91.05%, and 92.86%, respectively. Inhibitory effect of c9,t11-CLA on DNA synthesis (except for 25μM, 24h) was demonstrated by significantly less incorporation of 3H-TdR than the negative control (P<0.05 and P<0.01). To further investigate the influence of the cell cycle progression, we found that c9,t11-CLA may arrest the cell cycle of MCF-7 cells. Immunocytochemical staining demonstrated that incubation with different concentration of c9,t11-CLA at various times significantly decreased the expression of PCNA, Cyclin A, B1, D1 in MCF-7 cells compared to the negative control (P<0.01), whereas the expression of p16ink4a and p21cip/waf1, cyclin-dependent kinases inhibitors (CDKI), were increased. Conclusions: The cell growth and proliferation of MCF-7 cells is inhibited by c9,t11-CLA via blocking cell cycle, accompanying reduced expression of cyclin A, B1, D1 and enhanced expression of CDKI (p16ink4a and p21cip/waf1).

Concentration of linoleic acid from cottonseed oil by starch complexation

The extraction of linoleic acid from fatty acids(FA) of the cottonseed oil using starch–FA complexes was developed for the first time. We showed that starch can form inclusion complexes of different strengths with FA and that the different strengths stem from the differences in chain length, degree of unsaturation, and position of double bonds of FA. The optimal separation conditions were determined as follows: The inclusion temperature is 69 °C, the inclusion time is 30 min, the starch/FA mass ratio is 10:1, and the ratio of the volume of methanol–water solution and the mass of FA is 18:1. Compared to urea inclusion complexation, starch complexation has milder reaction temperature and shorter reaction time. Under these conditions, linoleic acid can be concentrated from 38.9% to 70.04% by one-off extraction. Moreover, the experimental results demonstrate the almost perfect reusability of starch. These results show that starch complexation is a promising method that can be used to obtain highly concentrated linoleic acid from cottonseed oil.

The Effect of Parity on Conjugated Linoleic Acid(CLA) Content in Milk Fat and CLA-Desaturase Index from Holstein Dairy Cows

The performance of lactating dairy cows and composition of the fatty acids in milk fat were measured to investigate the effect of parity on conjugated linoleic acid(CLA)in milk fat and△~9-desaturase indices from Holstein dairy cows.Milk samples of two hundred and thirty-five lactating Holstein dairy cows in north China were tested.In order to avoid possible confounding effects of diet and season,Holstein cows were fed a single diet and milk was sampled on the same day.The average content of cis-9,trans-11 CLA was 5.14 mg/g fatty acids in milk fat,varying between 1.5 and 10.5 mg/g fatty acids.The average content of cis-9,trans-11 CLA of primiparous cattle was 5.19 mg/g fatty acids in milk fat,while it was 5.11 mg/g fatty acids in multiparous animals,with no significant difference between them(P】0.05).There was a significant(P【0.05)difference between the△~9-desaturase index of cis-9 C14:l and cis-9 C16:l between primiparous and multiparous cattle but not(P】0.05)in the△~9-desaturase index of cis-9 C18:l and cis-9,trans-11 CLA.

Conjugated Linoleic Acid and Dietary Fats Differentially Affect Hepatic ACAT Activity and LDL-Cholesterol in Postweanling Pigs Fed Low-Fat Diets

ABSTRACT：Two separate studies tested the hypoth- esis that plasma low-density lipoprotein cholesterol LDL-C ） can be decreased by conjugated linoleic acid （CLA） by depressing hepatic acyl-coenzyme A： cholesterol acyltransferase （ACAT） activity. In the first experiment, 3 groups of 6 early-weaned piglets were fed low-fat diets containing either 1.5% CLA, 1.5% corn oil or 1.5% beef tallow;fat provided 8% of the energy intake. In the second experiment, 4 groups of 6 early-weaned piglets were fed high-fat di- ets containing either 15% beef tallow, 12% beef tal- low plus 3% CLA, 15% corn oil, or 12% corn oil plus 3% CLA; fat provided 29% of energy intake. Cholesterol was balanced across diets in both experi-ments. In pigs fed the low-fat diets, all dietary fats in- creased LDL-C and triacylglycerols and decreased high-density lipoprotein cholesterol （ HDL-C ） and very low-density lipoprotein cholesterol （VLDL-C）. LDL-C was the same in pigs fed low-fat tallow or low-fat CLA diets. However, ACAT activity was near- ly 80% higher in pigs fed the low-fat tallow diet than in pigs fed the low-fat CLA diets. All high-fat diets increased LDL-C, HDL-C and triacylglycerols equally with no effect on VLDL-C. There were no unique fat- ty acid effects of the high-fat diets on ACAT activity. We conclude that supplemental fats had differential effects on hepatic ACAT activity and LDL-C, but on- ly in pigs fed low-fat diets.

ELASTICITY OF MONOLAYER OF LINOLEIC ACID AND ITS POLYMER

The dynamic elasticity of linoleic acid monolayer on a subphase of 10** minus **4mol/L TbCl//3 at various surface pressure has been measured by means of dynamic oscillation method in measuring the change of surface pressure caused by periodic compression-expansion cycles of the barrier. The elasticity of monolayer increases with increasing of surface pressure linearly. The linoleic acid polymer monolayer has been obtained under UV-irradiation in situ when keeping a constant surface pressure. But the elasticity of the resulting polymerized monolayer is even smaller than that of its corresponding monomer monolayer. The elasticity of the polymerized linoleic acid monolayer decreases with increasing polymerization time. The explanation based on entropy has been presented. (Author abstract) 10 Refs.

Effects of Conjugated Linoleic Acids on Proliferation and Differentiation of Rat Preadipocytes

Conjugated linoleic acids （CLAs） are a generic term for linoleic acid isomers and have a variety of biological functions. After rat preadi- pocytes were incubated in CLAs-supplemented media, their proliferation and differentiation were observed by the cell count and the oil red O stai- ning. The results showed that the CLAs at different concentrations inhibited proliferation of the rat preadipocytes in a time- and dose-dependent manner. And the CLAs greatly decreased intracellular lipid content in mature adipocytes. Moreover, lipogenesis was inhibited by the CLAs in a dose-dependent manner. Therefore, the CLAs inhibit the lipogenesis by reducing the number of preadipocytes and decreasing the intracellular lipid

Increasing Conjugated Linoleic Acid Content in Milk and Cheese after Supplementing a Blend of Crude Soybean Oil Sediment Combined with Fish Oil to Grazing Dairy Cows

The aim of the work was to improve the healthy value of milk and cheese fatty acids (FA) by feeding a mix of crude soybean oil sediment (CSOS) combined with fish oil (FO) to grazing dairy cows. The CSOS is a by-product commonly discarded after oil extraction containing 3.3% moisture, 6% total ash and 70.7% oil, locally available, comparatively economic and easy to mix with other feed ingredients. The experiment lasted 55 days from September 30th to November 23th 2018 and was carried out at the dairy farm “Gacef” provider of milk to the dairy industrial plant “Capilla Del Señor” (CDS) located at the Villa María City, Córdoba Province, Argentine. A herd of 80 multiparous Holstein cows producing 24 kg-1 milk·cow-1·day-1 was used. The cows grazed an alfalfa and an oat pasture that represented about 47% of total dry matter (DM) intake supplemented at 8.5 kg DM·cow-1·day-1 with a total mixed ration (TMR) composed (DM basis) by cracked corn grain (35.18%), whole plant corn silage (31.98%), pelletized soyben meal (17.99%), the CSOS supplement (13.85%) and FO (0.99%). The TMR was supplied by halves after each milking time in groupal feeders yielding 1.4 kg·cow-1·day-1 of the CSOS and 0.1 kg·cow-1·day-1 of FO. Before the start of lipid supplementation, milk samples (5) were obtained from the farm-tank representing the standar or reference milk (Ref-Milk). After 21 days of supplementary lipid supply, additional milk samples (5) were obtained representing the modified milk (Mod-Milk). Milk samples were analyzed for chemical composition and milk FA profile. At each time, sufficient quantities of both (Ref- and Mod-Milk) were collected for manufacturing six types of cheeses. The results were analyzed through the Student-T test for independent observations. Oil supplementation did not modify (P > 0.05) the chemical composition of milk. Concentration of butyric acid (C4:0) in milk was not affected (P < 0.858). Concentration of total saturated FA (SFAs) in Ref-Milk averaged 58.83 g 100 g-1 FA and was decreased to 49.67 g 100 g-1 FA in Mod-Milk (P < 0.0001). Monounsaturated FA (MUFAs) increased (P < 0.001) from 32.03 g 100 g-1 FA in Ref-Milk to 38.13 g 100 g-1 FA in Mod-Milk (+19.07%) whereas polyunsaturated FA (PUFAs) increased (+36.1%) from 4.71 to 6.41 (P < 0.004). The Mod-Milk showed a significant (P < 0.002) reduction (-15.3% or 5.9 g 100 g-1 FA) for the total concentration of the potentially atherogenic fraction of milk FA (C12:0 to C16:0). The atherogenic index (AI) also decreased (P < 0.012) from 1.98 in Ref-Milk to 1.42 in Mod-Milk (-28.4%). Concentration of vaccenic acid (VA, trans-11 C18:1) in Mod-Milk averaged 7.77 g 100 g-1 FA which represented a 162 % increase (P < 0.0001) over that observed in Ref-Milk (2.95 g 100 g-1). Concentration of conjugated linoleic acid (CLA, cis-9, trans-11 C18:2) in Ref-Milk averaged 1.47 g 100 g-1 FA and showed an important increase (P < 0.002) in the Mod-Milk (3.86 g 100 g-1 FA, +163%). The omega 6/3 ratio resulted lower (P < 0.012) in the Ref-Milk (2.28) compared to the Mod-Milk (2.83). Milk and cheese FA composition were highly correlated (R2 = 0.99, P < 0.0001). The Mod-Cheeses showed similar results in AI, total concentration of SFAs, MUFAs and PUFAs compared to the milk of origin. Differences in FA composition between the cheeses made with the Ref- and Mod-Milk were equivalent to those described for milks. It is concluded that supplementation with a blend of CSOS supplement and FO was an effective way to improve the healthy value of dairy products by reducing contents of SFAs, atherogenic FAs and the atherogenicity index with a concomitant increase in VA and CLA. Modifications induced in the Mod-Milk were recovered in the Mod-Cheeses. The results obtained may help to reduce saturated fat intake and fight or prevent incidence of non-communicable, cardiovascular and chronic diseases.

High Linoleic Acid in the Food Supply Worldwide-What are the Consequences?

The macronutrient composition of food supply in China has altered dramatically in the past 70 years.Fat(oil)has increased more than 4.2-times while the carbohydrate content has declined by 34%.Vegetable oils are the major component of the fat intake and since these oils are rich in linoleic acid,there has been a significant rise in the consumption of this fatty acid(as much as a 4-fold rise).Linoleic acid has essential functions in the body in skin and as a precursor of prostaglandins and related compounds.The current intakes of linoleic acid are well in excess of the minimum requirements.In this review,the effects of a food supply rich in linoleic acid on pain in arthritis and headache,non-alcoholic fatty liver and neural function are explored,with emphasis on lipid mediators derived from linoleic acid and other long chain polyunsaturated fatty acids.The current world food systems have created an imbalance of dietary linoleic acid in relation to n-3 polyunsaturated fatty acids,and an imbalance in the lipid mediators derived from these polyunsaturated fatty acids which may be contributing to sub-optimal health status.

Influence of Mg/Al Molar Ratio on the Structures and Properties of Ru-Mg Alx Catalysts for Isomerization Linoleic Acid

With the knowledge on the significant effect of basic site and Ru on the catalytic performance of heterogeneous catalysts in the isomerization of linoleic acid to conjugated linoleic acid,a series of Ru-Mg Alx compounds with different basicity have been prepared by controlling the Mg/Al molar ratio. The results showed the catalysts with different basicity markedly influence the structure,the Ru dispersion,properties and catalytic performances for the isomerization reaction. The strong basic site is conductive to the high yield of CLA products. The strong basic site and the well-dispersion RuO2synergetic catalysis for the isomerization reaction,basic site and the well-dispersion RuO2synergetic effect are possibly via a Mg-O-Ru linkage.

Redox-sensitive prodrug nanoassemblies based on linoleic acid-modified docetaxel to resist breast cancers

Prodrug nanoassemblies, which can refrain from large excipients, achieve higher drug loading and control drug release, have been placed as the priority in drug delivery system. Reasoning that glutathione(GSH) and reactive oxygen species(ROS) are highly upgraded in tumor tissues which makes them attractive targets for drug delivery system, we designed and synthetized a novel prodrug which utilized mono thioether bond as a linker to bridge linoleic acid(LA) and docetaxel(DTX). This mono thioether-linked conjugates(DTX-S-LA) could self-assemble into nanoparticles without the aid of much excipients. The mono thioether endowed the nanoparticles redox sensitivity resulting in specific release at the tumor tissue. Our studies demonstrated that the nanoassemblies had uniform particle size, high stability and fast release behavior. DTX-S-LA nanoassemblies outperformed DTX solution in pharmacokinetic profiles for it had longer circulation time and higher area under curve(AUC). Compared with DTX solution, the redox dual-responsive nanoassemblies had comparable cytotoxic activity. Besides, the antitumor efficacy was evaluated in mice bearing 4 T1 xenograft. It turned out this nanoassemblies couldenhance anticancer efficacy by increasing the dose because of higher tolerance. Overall, these results indicated that the redox sensitivity nanoassemblies may have a great potential to cancer therapy.

STUDIES ON BIO-ANTIOXIDANTS——PROOXIDATION OF VITAMIN E ON THE AUTOXIDATION OF LINOLEIC ACID IN SODIUM DODECYL SULFATE MICELLES

The reaction of vitamin E (α-tocopherol) with linoleic acid containing peroxidized linoleic acid has been studied. No significant reaction was found in ethanol solution, whereas in sodium dodecyl sulfate micelles vitamin E reacted rapidly with peroxidized linoleic acid, and thereby induced the peroxidation of linoleic acid, leading to oxygen absorption. The reaction kinetics was studied in detail by u. v. spectroscopy, HPLC and ESR spectroscopy. It was found that the main product was α-tocopherone with α-tocopheroxy radical as the reaction intermediate. A mechanism involving two consecutive bimolecular reactions between peroxidized linoleic acid and a-tocopherol and between peroxidized linoleic acid and a-tocopheroxy radical, with rate constant 2.93 and 6.21 mol/L-1s-1 respectively is proposed. The micellar effect on the reaction is discussed.

STUDIES ON BIO-ANTIOXIDANTS (Ⅴ)——INHIBITION OF AUTOXIDATION OF LINOLEIC ACID BY VITAMIN E, VITAMIN C AND LIPOPHILIC VITAMIN C DERIVATIVES IN MICELLES

The antioxidation activity of vitamin E, vitamin C and lipophilic derivatives of vitaminC, i.e. ascorbyl--6-caprylate, 6-laurate and 6-palmitate, on the autoxidation of linoleic acidwere studied in SDS, Triton X-100 and CTAB micelles. The effect of the lipophilicity ofthe antioxidants and micellar effects on the antioxidation activity are discussed.

STUDY ON THE FREE RADICALS PRODUCED FROM PHOTOLYSIS OF PEROXIDIZED LINOLEIC ACID BY ESR SPIN TRAPPING TECHNIQUE

Lipid peroxidation of polyunsaturate fatty acid is the main reason for the production of toxic materials in putrid food oil. The free radicals and other products produced from the peroxidation process can damage the membrane, protein and DNA and may induce cancer and other brain, myocardial and vascular diseases. Lipid peroxidation is also an important reason for aging. So it has raised a wide interest and attention of biological and

A Study on the Anticancerous Mechanism of Linoleic Acid Polyphase Liposome of Liquid Crystalline State by Means of SAXS and ^(31)P-NMR

In recent years, close attention has been paid to the study of liposomes as the carrier of the anticancerous drug, which has many advantages in the therapeutics, such as increasing the toxicity of the drug. alleviating metamorphosis and immunity reaction; improving the biological utilization ratio of the drug; selectively killing and inhibiting the cancer cells or checking the reproduction of the cancer cells, and so on. At present, peo-