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).

产共轭亚油酸Lactiplantibacillus plantarum ZFM804的筛选及益生特性评价

作者以发酵食品中分离的8株乳酸菌为研究对象,采用紫外分光光度法筛选出产共轭亚油酸(CLA)的菌株,进一步对其体外益生特性进行评价。结果表明,Pediococcus acidilactici ZFM801、Leuconostoc mesenteroides ZFM803、Lactiplantibacillus plantarum ZFM804、Lactiplantibacillus plantarum ZFM805、Lactiplantibacillus plantarum ZFM806、Weissella cibaria ZFM810具有产CLA的能力,其中Lactiplantibacillus plantarum ZFM804产CLA能力最高(质量浓度达21.7 mg/L),且CLA异构体分别为c9,t11-CLA和t10,c12-CLA。益生特性评价结果表明,Lactiplantibacillus plantarum ZFM804对3种致病菌的共凝聚率均高达25%以上。耐受性结果表明,Lactiplantibacillus plantarum ZFM804可耐受质量分数4%的NaCl和质量分数0.1%的胆盐;同时Lactiplantibacillus plantarum ZFM804在模拟胃肠液环境下同样表现出较高的耐受性,且p H 4.5时存活率高达60%以上;其次Lactiplantibacillus plantarum ZFM804对藤黄微球菌、金黄色葡萄球菌具有显著的抑制作用。综上,Lactiplantibacillus plantarum ZFM804具有高产CLA的潜能和良好的益生特性。

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.

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.

Concentration of α-Linoleic Acid of Perilla Oil by Gradient Cooling Urea Inclusion

In this study, production of ct-linoleic acid concentrated from crude perilla oil by gradient cooling urea inclusion was optimized. The fatty acid composition was determined after ethyl esterification by gas chromatography （GC）. In this process, orthogonal experiment was carried out. Under optimum conditions, the maximum amount of α-linoleic acid （91.5%） was obtained at a urea to fatty acid ratio of 3, a solvent to fatty acids ratio of 7, a reaction temperature of 348 K and a crystallization time of 690 min. A simple method of gradient cooling urea inclusion was used to purify α-linolenic acid by using urea to form inclusion complexes with the saturated and the less unsaturated fatty acids, which enhanced the purity of α-linoleic acid ethyl ester by above 90%.

Influence of dietary conjugated linoleic acid on growth, fatty acid composition and hepatic lipogenesis in large yellow croaker (Pseudosciaena crocea R.)

We examined the effects of conjugated linoleic acid (CLA) on growth, fatty acid composition and enzyme activity of fatty acid oxidation in the liver of large yellow croaker. We divided 1600 fish (average initial weight 150 g) into 4 groups and reared them in 8 cages. Four dietary treatments were formulated to contain 0%, 1%, 2% and 4% (w/w) CLA, respectively. The fish were fed for 10 weeks ad libitum twice daily. We found that the dietary CLA had no effect on growth, biometric parameters and whole body proximate (P>0.05), but showed some significant effects on the fatty acid composition in both muscle and the liver. The activities of lipogenic enzymes were slightly depressed in fish fed with increasing levels of CLA when compared with control (P>0.05). Dietary CLA supplementation had no effects on liver lipid content, but significantly increased the contents of saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) (P<0.05) and decreased monounsaturated fatty acid (MUFA) content in both muscle and the liver. Dietary CLA inclusion resulted in significant increases of the biologically active cis-9, trans-11 and trans-10, cis-12 isomers in both tissues (P<0.05). The total accumulation of CLA was higher in the liver (3.83%, w/w) than in muscle (3.77%, w/w) when fed with 4% (w/w) CLA. This study demonstrates that large yellow croakers are capable of absorbing and depositing CLA and long-chain n-3 PUFA in the liver and muscle, showing that this species fed with CLA could be an important human food source for these healthful fatty acids.

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.

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.

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.

Role of free fatty acids in proliferation of rat hepatic stellate cells(Ⅱ)

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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.

The Effect of Dietary Vegetable Oilseeds Supplement on Fatty Acid Profiles in Milk Fat from Lactating Dairy Cows

To determine the effect of dietary supplementation with vegetable oilseeds on the composition of bovine milk fatty acids （FAs）, 40 Holstein dairy cows were used with a complete randomized design. At the beginning of the experiment, the cows were 150±25 day in milk （DIM）. Total duration of the experiment was six weeks. Measurements were made during the last three weeks. Cows in four treatments were fed with a basal diet （CT） or basal diet supplemented with either whole full fat soybean （WFS）, full fat expanded soybean （FPS） or whole full fat soybean with whole cottonseed and full fat expanded soybean （MIX）. The composition of the milk fat was analyzed by gas chromatography. Relative to control, the conjugated linoleic acid （CLA） concentration in milk fat from cows on FPS was significantly increased by 83.88% （P〈 0.05）. The proportions of C12：0 were decreased by 35.7, 35.51, and 38.65% in milk fat from cows on WFS, MIX, and FPS compared with cows on CT. Similar decreases in C 14：0 were 23.83, 24.85, and 31.48% in WFS, MIX, and FPS treatments, respectively. Feeding vegetable oilseeds increased the proportion of healthy FAs （mainly CLA）, whereas decreased the concentratiofi of C12：0 and C14：0. Therefore, milk and dairy products would have higher nutritive and therapeutic value.

Preparation of Conjugated Linoleic Acid and Identification of Its Isomers

Conjugated linoleic acid(CLA)is a kind of fatty acid with physiological activities and potential appli-cation prospect ,A synthesis method of conjugated linoleic acid and a purification technology were studied .CLA was prepared and purified by urea-complexation and conjugation using safflower oil as raw material,The purity of CLA and total recovery of the product was more than 95% and 48%,respectively,The main isomers produced in alkali-catalyzed conjugation were identified by gas chromatography (GC)linked to mass spectrometry(MS) and Fourier transform infrared spectroscopy(FTIR),The total amount of the two main isomers (9cis,11trans-and 10trans,12cis-CLA) determined by GC was more than 90% of the product.

LA-ICP-MS测定单颗粒氨基膦酸螯合树脂中的铀分布

以利用氨基膦酸螯合树脂从湿法磷酸(WPA)中回收铀为研究背景,对单颗粒氨基膦酸螯合树脂中铀分布进行研究,得到以下结论:确定激光剥蚀电感耦合等离子体质谱仪(LA-ICP-MS)最佳的激光频率为6 Hz、束斑直径为44μm、能量密度为6 J/cm^(2)。选择吸附饱和的树脂和洗脱完全的树脂分别作为吸附和淋洗过程的外标,对其进行均匀性测试,吸附饱和树脂中铀含量的相对标准偏差为3.87%(n=9),洗脱完全树脂中铀含量的相对标准偏差为3.52%(n=9),均一性良好。利用LA-ICP-MS对氨基膦酸螯合树脂中的铀进行原位微区分析,结果表明:铀在树脂上的吸附过程是由外向内逐渐完成,淋洗过程是由外向内逐渐完成,树脂内外铀浓度逐渐均匀统一,最终达到吸附饱和和淋洗完全。

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).

Effect of Diet Supplementation with Combinations of Soybean and Linseed Oils on Milk Production and Fatty Acid Profile in Lactating Dairy Ewes

Thirty-six Pampinta ewes were used in a completely randomized design to examine the effectiveness of soybean (SO) and linseed (LO) oils to reduce the concentration of the atherogenic fatty acids (FA) of milk (C12:0 to C16:0) and increase the content of conjugated linoleic (cis-9, trans-11 C18:2) also called rumenic acid (RA) and vaccenic acids (trans-11C18:1, VA). Six ewes per treatment received a Control diet alone (71% alfalfa hay and 29% concentrate) or supplemented (0.24 kg/ewe·day) with pure oils (SO100 or LO100) or their blend at (%) SO75-LO25, SO50-LO50 and SO25-LO75. Milk yield, milk fat content and milk fat secretion were not affected. Milk protein content resulted higher in SO75-LO25, SO50-LO50 and SO25-LO75 without changes in milk protein yield. Total solid content of milk tended (p p p < 0.001) by oils reaching a minimum value of 1.89 in LO100. Feeding polyunsaturated oils at 7% of total dry matter (DM) intake did not affect the productive response of dairy ewes resulting in an effective tool to improve the healthy value of milk fat. The SO50-LO50 blend showed the highest number of healthy changes in milk FA composition.

Linoleic Acid Activates GPR40/FFA1 and Phospholipase C to Increase [Ca^(2+)]_i Release and Insulin Secretion in Islet Beta-Cells

Objective To elucidate GPR40/FFA1 and its downstream signaling pathways in regulating insulin secretion. Methods GPR40/FFA1 expression was detected by immunofluorescence imaging. We employed linoleic acid (LA), a free fatty acid that has a high affinity to the rat GPR40, and examined its effect on cytosolic free calcium concentration ([Ca2+]i) in primary rat β-cells by Fluo-3 intensity under confocal microscopy recording. Downregulation of GPR40/FFA1 expression by antisense oligonucleotides was performed in pancreatic β-cells, and insulin secretion was assessed by enzyme-linked immunosorbent assay. Results LA acutely stimulated insulin secretion from primary cultured rat pancreatic islets. LA induced significant increase of [Ca2+]i in the presence of 5.6 mmol/L and 11.1 mmol/L glucose, which was reflected by increased Fluo-3 intensity under confocal microscopy recording. LA-stimulated increase in [Ca2+]i and insulin secretion were blocked by inhibition of GPR40/FFA1 expression in β-cells after GPR40/FFA1-specific antisense treatment. In addition, the inhibition of phospholipase C (PLC) activity by U73122, PLC inhibitor, also markedly inhibited the LA-induced [Ca2+]i increase. Conclusion LA activates GPR40/FFA1 and PLC to stimulate Ca2+ release, resulting in an increase in [Ca2+]i and insulin secretion in rat islet β-cells.

Effect of cis-9,trans-11-conjugated linoleic acid on cell cycle of gastric adenocarcinoma cell line(SGC-7901)

AIM: To determine the effect of cis-9, trans-1l-conjugated linoleic acid ( c9, tl 1-CLA) on the cell cycle of gastric cancer cells( SGC-7901 ) and its possible mechanism in inhibition cancer growth.METHODS: Using cell culture and immunocytochemicaltechniques, we examined the cell growth, DNA synthesis,expression of PCNA, cyclin A, B1, D1, pl6nink4a and p21clp/wafl ofSGC-7901 cells which were heated with various c9, tll-CLAconcentrations (25,50,100 and 200μnol@L-1)of c9, tll-CLA for 24and 48 h, with a negative control (0.1% ethane).RESULTS: The cell growth and DNA synthesis of SGC-7901cells were inhibited by c9, tll-CLA. SGC-7901 cells. Eightday after treatment with various concentrations of c9, tl1-CLA mentioned above, the inhibition rates were 5.92 % ,20.15 % ,75.61% and 82.44 % ,respectively and inhibitory effeotof c9, tll-CLA on DNA synthesis (except for 25 tmol/L,24h) showed significantly less 3H-TdR incorporation than thatin the negative controls (P ＜ 0. 05 and P ＜ 0. 01).Immunocytochemical staining demonstrated that SGC-7901cells preincubated in media supplemented with different c9,tl1-CLA concentrations at various times significantlydecreased the expressions of PCNA (the expression rateswere7.2-3.0 %,24 h and 9.1-0.9 % at 48 h, respectively),Cyclin A (l1.0-2.3 %, 24 h and 8.5-0.5 % ,48 h), B1 (4.8-1.8% at 24 h and 5.5-0.6 % at 48 h)and D1 (3.6-1.4 % at 24 hand 3.7 %-0 at 48 h) as compared with those in the negativecontrols(the expressions of PCNA, Cyclin A, B1 and D1were 6.5 % at 24h and 9.0 % at 48 h, 4.2% at 24h and5.1% at 48 h, 9.5 % at 24h and 6.0 % at 48 h,respectively)(P＜ 0.01), whereas the expressions of p16ink4a and p21clp/waf1,cyclin-dependent kinases inhibltors(CDKI), were increased.CONCLUSION: The cell growth and proliferation of SGC-7901cell is inhibited by c9, tll-CLA via blocking the cell cycle,with reduced expressions of cyclin A, B1 and D1 andenhanced expressions of CDKI( p16ink4a and p21cip/waf1).