T11 Conjugated Linoleic Acid Research Articles

Comparison of milk and grass composition from grazing Irish dairy herds with and without milk fat depression

BackgroundThis study investigated the factors relating to pasture chemical and fatty acid (FA) composition that influence the milk fat percentage of spring calving, grazing dairy cows. The relationship between milk fat percentage and FA composition of the milk in these herds was also investigated.ResultsMilk protein percentage, milk casein percentage and cheddar cheese yield were increased in milk from HMF herds. Cows from LMF herds did not have negatively altered milk processability including rennet coagulation time (RCT), pH and ethanol stability. Crude protein, NDF, ADF, ether extract and total FA content of pasture was not different between LMF and HMF herds. Milk fat concentration of conjugated linoleic acid (CLA) t10, c12 was not different between HMF and LMF herds. Pre-grazing herbage mass and pasture content of crude protein, neutral detergent fibre (NDF) and total FA were similar between HMF and LMF herds. Pasture offered to LMF herds had a higher concentration of monounsaturated fatty acids (MUFA). A strong negative relationship (r = -0.40) was evident between milk fat percentage and pasture crude protein content for MMF herds (3.31–3.94% milk fat).ConclusionsThis research reports improved milk protein percentage, milk casein percentage and cheddar cheese yield from HMF herds compared to LMF herds. Milk processability was not impacted by low milk fat percentage. Pasture NDF and total fatty acid content was similar in HMF herds and LMF herds. Milk fat percentage had a strong negative association (r = -0.40) with pasture crude protein content in MMF herds (MF 3.31–3.94%). Correlation values between pasture chemical and FA composition and milk fat percentage in LMF herds and HMF herds were low, indicating that diet is not the only causative factor for variation in milk fat of grazing dairy cows. Comparison of milk fatty acid composition from herds with and without milk fat depression suggests that there may be other fatty acids apart from CLA t10, c12 that contribute to the inhibition of milk fat synthesis during milk fat depression in grazing herds.

Effects of Dietary Supplementation of Conjugated Linoleic Acids and Their Inclusion in Semen Extenders on Bovine Sperm Quality.

Simple SummarySuboptimal fertility in males accounts for about two-thirds of infertility cases, thus being of serious concern for the dairy industry, where optimal fertility is fundamental for farm profitability. Although genetic defects responsible for subfertility have been identified, the role of seminal compounds on fertility remain unclear. Feeding rumen-protected isomers of conjugated linoleic acid (CLA) to dairy cows reportedly enhances circulating insulin-like growth factor I (IGF-I) levels. In breeding bulls, the IGF-I concentration in seminal plasma has been positively correlated with fertility rates. Therefore, the objective of the study was to evaluate the effect of dietary CLA supplementation and of their inclusion to the semen extender on bovine semen quality and freezability.Isomers of conjugated linoleic acid (CLA) enhances circulating insulin-like growth factor I (IGF-I) levels. Furthermore, fertility rate of breeding bulls is positively correlated to seminal plasma IGF-I concentration. Our objective was to evaluate the effect of dietary CLA supplementation and inclusion to the semen extender on bovine semen quality and freezability. Fourteen bulls, randomly assigned to control (CTL) and CLA (50 g/day) groups, were supplemented for 10 weeks. Samples were collected at Weeks −2 (before supplementation), 0, 4, 6 (during supplementation), 10, and 11 (after supplementation). Blood and seminal plasma were analyzed for IGF-I; the ejaculates were frozen in the following subgroups: CTL (no addition to semen extender), CLA c9, t11 (50 µM), CLA c9, t11 (100 µM), CLA t10, c12 (50 µM), CLA t10, c12 (100 µM), and CLA mix (50 µM each of CLA c9, t11 and CLA t10, c12). Sperm motility, morphology, viability, mitochondrial membrane potential, and reactive oxidative species were assessed. CLA supplementation decreased ejaculates’ total volume, increased sperm concentration, beat cross frequency, and decreased oxidative stress; it also increased plasma and seminal plasma IGF-I levels compared to the CTL. The inclusion of CLA c9, t11 100 µM and CLA mixture in the extender increased live spermatozoa percentage post-thawing compared to other groups. Our results show a beneficial effect of CLA supplementation on semen quality; however, further studies evaluating fertilization rates are necessary to corroborate the results.

Butyrivibrio fibrisolvens F7 dietary supplementation increases levels of cis 9-trans 11 conjugated linoleic acid in gut and adipose tissue in mice

Abstract Ruminant-origin food products are the richest source of natural conjugated linoleic acid (CLA) in human diets, and cis-9, trans-11 (c9, t11) is the most abundant isomer of CLA. Butyrivibrio fibrisolvens, a rumen microbe, is considered responsible to have the highest CLA-producing potential. The present study was carried out to identify and characterize a rumen-origin B. fibrisolvens strain that can produce high levels of c9, t11 CLA, as well as to evaluate how dietary supplementation with the strain influenced c9, t11 CLA levels in the gut and adipose tissue in mice. A total of 257 anaerobic strains were isolated from buffalo, cattle, and goat rumen samples, and 24 isolates were identified as Butyrivibrio spp. based on 16S rRNA sequencing. 22 isolates of Butyrivibrio spp. were found to be B. fibrisolven-like. These strains were tested for their potential to produce CLA at varied concentrations (0, 100, 200, 300, 400, 500 μg/mL) of linoleic acid (LA) as substrate after incubating for different durations (0, 2, 4, 6, 12, 24 and 36 h). Results of the study reflected that Butyrivibrio fibrisolvens F7 converted almost 74% of LA of 200 μg/mL concentration to c9, t11 CLA after 24 h and formed the maximum CLA (147.39 μg/mL). B. fibrisolvens F7 (GenBank Accession No: KU507371) was found to be acid and bile tolerant and exhibited good cell surface hydrophobicity in n-hexadecane and toluene B. fibrisolvens F7 dietary supplementation in mice, combined with a high-LA diet, increases c9, t11 CLA levels in adipose tissue and gut by more than three folds. The results of this study significantly increase the possibility of employing B. fibrisolvens F7 as a probiotic supplement for animals to maintain a steady supply of natural c9, t11 CLA in the host.

Conjugated linoleic acid improves endothelial Ca2+ signaling by blocking growth factor and cytokine-mediated Cx43 phosphorylation

Sustained Ca2+ burst signaling is crucial for endothelial vasodilator production and is disrupted by growth factors and cytokines. Conjugated linoleic acid (CLA), a Src inhibitor in certain preparations, is generally regarded as safe during pregnancy by the FDA. Multiple CLA preparations; t10, c12 or c9, t11 CLA, or a 1:1 mixture of the two were administered before growth factor or cytokine treatment. Growth factors and cytokines caused a significant decrease in Ca2+ burst numbers in response to ATP stimulation. Both t10, c12 CLA and the 1:1 mixture rescued VEGF165 or TNFα inhibited Ca2+ bursts and correlated with Src-specific phosphorylation of connexin 43. VEGF165, TNFα, and IL-6 in combination at physiologic concentrations revealed IL-6 amplified the inhibitory effects of lower dose of VEGF165 and TNFα. Again, the 1:1 CLA mixture was most effective at rescue of function. Therefore, CLA formulations may be a promising treatment for endothelial dysfunction in diseases such as preeclampsia.

Conjugated linoleic acids diminish glycogen synthase and glycogen synthase kinase-3 expression in muscle cells of C57BL/6J mice - in vitro and in vivo study.

Conjugated linoleic acids (CLA) have been extensively advertised as dietary supplements to reduce fat and increase muscle mass. However, the role of CLA in glycogen metabolism is still largely unknown. The aim of this study was to assess the effect of CLA on glycogen synthesis in vitro (CCL 136 cell line human) and CLA in vivo (C57BL/6J mice). The materials used were the CCL 136 muscle cell line and muscles of female C57BL/6J mice (n = 52), housed at animal laboratory facility and feed with "MURIGRAN", a standard feed prepared for rodents (Agropol, Poland). Chemically pure fatty acids were added to soybean oil. CLA isomers (c9,t11 CLA, t10,c12 CLA, and as a mixture (1:1)) were administered with feed. Supplementation in mice started at week 6 of age and lasted for 4 weeks. Methods used in the study were real time- PCR - quantification of gene expression, Western blot glycogen synthase kinase-3 (GSK3α 9) and glycogen synthase (GS) protein, glycogen staining by PAS. Quantitative determination of glycogen by spectrophotometry and intracellular reactive oxygen species was measured the intracellular oxidation of dichloro-dihydro-fluorescein diacetate (DCFH-DA). In vitro data showed that GS and GSK3 expression was lower in cells cultured with different CLAs and a mixture of CLAs. GS gene expression was significantly decreased in cells cultured with c9, t11 CLA (P < 0.04) and t10, c12 CLA (P < 0.05) as well as the mixture of both isomers. The GSK3α gene expression was reduced in cells cultured with a mixture of CLA (P < 0.02), whereas phosphorylation of GSK3α increased in cells cultured with c9, t11 CLA GSK3α (P < 0.05). In vivo data showed a reduction in the glycogen concentration among mice fed a diet containing t10, c 12 CLA and a mixture of CLA isomers. We conclude that both CLA isomers can affect the synthesis of glycogen in muscle cells through the regulation of GS and GSK3α gene expression.

The influence of conjugated linoleic acid on the expression of peroxisome proliferator-activated receptor-\u03b3 and selected apoptotic genes in non-small cell lung cancer

In recent years, peroxisome proliferator-activated receptor-γ (PPARγ) has been intensively studied. Because its activation is often associated with changes in the expression level of various apoptotic genes, many studies have emphasized the role of PPARγ as an important anticancer agent. However, in different types of cancer, different genes are influenced by PPARγ action. Previous studies showed that conjugated linoleic acid (CLA) was able to induce apoptosis, upregulate PPARG gene expression and activate PPARγ protein in certain human cancer cell lines. Moreover, some PPARγ agonists inhibited the growth of human lung cancer cells through the induction of apoptosis. Nevertheless, the impact of CLA on PPARγ mRNA and protein levels in non-small cell lung cancer (NSCLC) cell lines has not been investigated thus far. Therefore, in our study, we analysed the influence of the c9,t11 linoleic acid isomer on the expression of PPARG and other genes involved in the apoptotic response (BCL-2, BAX, and CDKN1A) in two NSCLC cell lines of different histological origin (A549 and Calu-1) and in normal human bronchial epithelial Beas-2B cells. Cells were treated with several doses of c9,t11 CLA, followed by RNA and protein isolation, cDNA synthesis, real-time quantitative PCR (RT-qPCR) and Western blot analysis. We showed that the investigated CLA isomer was able to enhance the expression of PPARγ in the examined cell lines and alter the mRNA and protein levels of genes involved in apoptosis. Fluorescent staining and MMT assay revealed the antiproliferative potential of CLA as well as its ability to activate pathways that lead to cell death.

Effects of forage species and feeding systems on rumen fermentation, microbiota and conjugated linoleic acid content in dairy goats

The objective of this experiment was to investigate the effects of forage species and feeding systems on ruminal fermentation, microbiota (Butyrivibrio fibrisolvens, Fibrobacter succinogenes and total bacteria) and conjugated linoleic acid (CLA) concentration of milk in dairy goats. Twenty female crossbred Saanen lactating goats (~35 ± 3.0 kg bodyweight) in early to mid-lactation stage were assigned to a 45-day completely randomised-design feeding experiment, with the following four forage (roughage) treatments: cut-and-carry grass (CG), grazing of grass (GG), cut-and-carry leucaena (CL) and grazing of leucaena (GL; n = 5). All animals were given concentrate equivalent to 1.5% of their bodyweight. The grass used in the study was napier Pak Chong 1 grass (Pennisetum purpureum × Pennisetum americanum hybrid). The results showed that irrespective of the type of forage, grazing goats (GG and GL) had a higher (P &amp;lt; 0.05) forage intake and, thus, total dry-matter and crude-protein intakes than did those fed indoors (CG and CL). However, the intake of C18:2n6 and particularly of C18:3n3 was generally higher for grass-fed goats than for leucaena-fed goats. Treatments did not exert significant differences on rumen fermentation characteristics. However, the populations of B. fibrisolvens, F. succinogenes and total bacteria were significantly (P &amp;lt; 0.05) higher in grazing goats (GG and GL) than in their counterparts fed with the cut-and-carry system (CG and CL). Goats in the grazing system also had a higher (P &amp;lt; 0.05) milk yield, and milk fat, c9, t11 CLA and omega-3 fatty acid concentrations than did those in the cut-and-carry system and only grazing goats produced detectable levels of t10, c12 CLA in milk. Putting the above together, it can be concluded that allowing dairy goats to outdoor grazing stimulates a higher forage intake, including that of C18:2n6 and C18:3n3, as well as enhancing population of B. fibrisolvens (involved in the synthesis of milk CLA), resulting in a higher milk yield, and enhances c9, t11 and t10, c12 CLA in goat milk.

Efecto de la especie y la edad de rebrote en el perfil de ácidos grasos de leguminosas y arbustivas tropicales

Se evaluó el efecto de tres edades de rebrote (4, 8 y 12 semanas) sobre la producción de forraje, calidad nutricional y perfil de ácidos grasos en leguminosas herbáceas: Clitoria ternatea, Pueraria phaseoloides, Canavalia brasiliensis, Centrosema molle, Centrosema macrocarpum, Alysicarpus vaginalis y Lablab purpureus; en leguminosas arbustivas: Cratylia argentea, Gliricidia sepium, Desmodium velutinum, Cajanus cajan y Leucaena leucocephala; y en una arbustiva no leguminosa: Moringa oleifera (Moringaceae). Se utilizó un diseño de parcelas divididas con bloques al azar, en el cual la parcela principal fue la especie forrajera y la subparcela la edad de rebrote. Los principales ácidos grasos presentes en las especies fueron el ácido palmítico (C16:0), ácido linolénico (C18:3) y linoleico (C18:2). Sin embargo, en las leguminosas herbáceas y arbustivas, el contenido de ácidos grasos fue diferente y disminuyó con la edad de rebrote en los dos grupos. La relación C18:2/C18:3 fue mayor en las leguminosas herbáceas que en las arbustivas, lo cual podría resultar en una mayor concentración de ácido linoleico conjugado (ALC) en la grasa de la leche. La leguminosa Cajanus cajan presentó el mayor (p&lt;0,05) contenido de ácido linolénico (C18:3) y de precursores de ALC en las tres edades de rebrote evaluadas, lo cual sugiere que su uso en la alimentación de bovinos en sistemas de doble propósito resultaría en concentraciones altas de ALC c9 t11 en la grasa de la leche, en comparación con otras especies.

Effect of diets supplemented with different conjugated linoleic acid (CLA) isomers on protein expression in C57/BL6 mice.

BackgroundThe individual genetic variations, as a response to diet, have recently caught the attention of several researchers. In addition, there is also a trend to assume food containing beneficial substances, or to supplement food with specific compounds. Among these, there is the conjugated linoleic acid (CLA), which has been demonstrated to reduce fat mass and to increase lean mass, even though its mechanism of action is still not known. We investigated the effect of CLA isomers (CLA c9,t11 and CLA t10,c12) on the proteomic profile of liver, adipose tissue, and muscle of mouse, with the aim of verifying the presence of a modification in fat and lean mass, and to explore the mechanism of action.MethodsC57/BL6 mice were fed for 2 months with different diets: (1) standard chow, (2) CLA c9,t11 diet, (3) CLA t10,c11 diet, (4) CLA isomers mixture diet, and (5) linoleic acid diet. The proteomic profile of liver, white adipose tissue, and muscle was investigated. Statistical significance of the spots with an intensity higher than twofold in expression compared to the control was tested using student’s t test (two-tail).ResultsWe found that both isomers modulate the proteomic profiles of liver, adipose tissue, and muscle by different mechanisms of action. Liver steatosis is mostly due to the isomer CLA t10,c12, since it alters the expression of lipogenetic proteins; it acts also reducing the adipose tissue and increasing fatty acid oxidation in muscle. Conversely, CLA c9,t11 has no relevant effects on liver and adipose tissue, but acts mostly on muscle, where it enhances muscular cell differentiation.ConclusionsAdministration of CLA in humans has to be carefully personalized, since even considering the presence of a species-specific effect, adverse effects might occur on long-term supplementation. Here we demonstrated that, in mouse, CLA is effective in reducing fat mass, but it also induces liver steatosis. The increase of lean mass is linked to an induction of cell proliferation, which, on long-term supplementation, might also lead to adverse effects.

Fatty acid profile and health lipid indices in the raw milk of ewes grazing part-time and hemp seed supplementation of lactating ewes

This experiment was designed to evaluate the effects of the feeding system (indoor or part-time grazing) of ewes and dietary supplementation with hemp seed (non-drug varieties of Cannabis sativa L.) on milk production and the composition of milk fatty acids (FAs). The experimental diets were constituted as a 2 x 2 factorial arrangement of feeding system (I: indoors and receiving 1400 g dry matter (DM) grass hay/d or pasture grazing (PG)–4 h/day + 700 g DM grass hay/d), and with or without hemp seed (Hs) supplementation (-Hs = no hemp seed vs. +Hs = 175 g/d hemp seed). All animals received 700 g DM/day of a concentrate for lactation. Feeding the PG diets increased raw milk production and yields of fat, protein and lactose. Feeding +Hs increased fat-corrected milk, milk fat content and fat yield significantly while the combination of +Hs and PG increased fat-corrected milk and fat yield significantly. Milk protein content was not affected by dietary factors. Feeding the I diets increased the proportion of short-chain FAs (C4:0 - C10:0), at the expense of medium-chain FAs (12 to 17 C units). Feeding +Hs decreased the proportion of short-chain FAs, medium-chain FAs and hypercholesterolaemic FA (sum of C12:0, C14:0, C16:0) and increased the trans-vaccenic acid (C18:1 t11, VA), α-linolenic acid (C18:3 n-3, ALA), conjugated linoleic acid (CLA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrations in milk fat significantly. The combination of hemp seed and part-time grazing produced the highest proportion of c9,t11 CLA, t10,c12 CLA and n-3 FA (sum of ALA, EPA, DHA) in milk fat. The polyunsaturated fatty acid (PUFA)/saturated fatty acid (SFA) ratios in the milk from ewes grazing part time were significantly higher, whereas the atherogenicity index (AI), thrombogenic index (TI) and linoleic acid (LA)/ALA ratio were significantly lower compared with the milk of indoor-fed ewes. Supplementing with +Hs has a similar effect of increasing the PUFA/SFA ratio and lowering of the AI, TI and LA/ALA ratio. It was concluded that pasture grazing combined with hemp seed had a synergistic effect on milk production and fat yield without altering the milk protein content in ewes. This combination has favourable effects on milk FA profile from the human consumer’s point of view by increasing the nutritional quality of milk.Keywords: α-linolenic acid, atherogenicitiy index, Cannabis sativa, c9,t11 CLA, n-6/n-3 FA

Dietary CLA supplementation of pigs confers higher oxidative stability to Ciauscolo and Fabriano salami produced from their meat with no negative impact on the physico‐chemical, microbiological and sensorial characteristics

It has been reported that conjugated linoleic acid (CLA) isomers are considered particularly beneficial to human health and affect the technological properties of pork meat products such as salami. The objective of this study was to evaluate the effect of 0.5% CLA supplementation of heavy pig diets on the chemical composition, total fatty acids (FA), oxidative stability, sensory and microbial properties of Ciauscolo and Fabriano salami. The incorporation of CLA into the diet did not modify the chemical, microbial or sensory descriptive analysis of the salami. The CLA dietary supplementation changed the proportions of FA, in particular leading to an increase in the proportion of saturated fatty acids and CLA in both Ciauscolo and Fabriano salami. The results of consumer testing showed a higher degree of liking by consumers when the CLA sample was accompanied by product information, demonstrating the strong influence of the label on consumer perception. The interesting finding was the increase in the oxidative stability of the salami at the end of ripening. This confirms the hypothesis that CLA can affect the saturated and monounsaturated fatty acids/monounsaturated FA ratio in meat products and possesses antioxidative properties that can be transferred, through dietary supplementation, to salami.Practical applications: Feeding a 0.5% CLA diet to finisher pigs resulted in changes in the proportions of FA and enhanced the oxidative stability of salami but did not modify the sensory properties of the products. More research is needed to find the right inclusion level of CLA to be considered optimal from the point of view of producing a high quality product with superior organoleptical, technological and potential health‐related properties.Production of value‐added meat products, such as conjugated linoleic acids (CLA) enriched Ciauscolo and Fabriano salamis, by the inclusion of the c9 t11 and t10 c12 CLA isomers in the swine diet.

CLA and EPA inhibit LPS-induced prostaglandin release from bovine endometrial cells through an NF-κB-dependent signaling mechanism

Although their action in antagonizing arachidonic acid metabolism is a key antiinflammatory effect of conjugated linoleic acid (CLA) and omega-3 polyunsaturated fatty acids (n-3 PUFA), these molecules have other antiinflammatory effects that might occur upstream of altered eicosanoid production. We examined the effects of two CLA isomers (c9,t11 and t10,c12 isomers), n-3 PUFA (EPA and DHA), and κNF-κB inhibitor (ammonium pyrrolidine dithiocarbamate (PDTC)) on lipopolysaccharide (LPS)-induced secretion of prostaglandins (PGE 2 and PGF 2a ) by bovine endometrial (BEND) cells. LPS increased PGE 2 and PGF 2a concentrations in BEND cell- conditioned media in a concentration- and time-dependent manner. The c9,t11 CLA isomer and EPA decreased prostaglandin response to LPS. Addition of PDTC, alone or in combination with c9,t11 CLA or EPA, inhibited LPS-induced eicosanoid release into the culture medium. Results indicate that the c9,t11 CLA isomer and EPA inhibit the endometrial prostaglandin release in cattle and that these molecules may act through an NF-κB signaling mechanism.

Effect of the cryopreservation method used, the embryonic stage and the use of conjugated linoleic acid isomers on the cryotolerance of in vitro-produced bovine embryos

Conjugated linoleic acid (CLA) might be able to improve the cryotolerance of in vitro-produced (IVP) embryos. The effect of two CLA isomers on the cryotolerance of bovine IVP embryos, as well as that of the stage of embryonic development and the method used for cryopreservation was evaluated by three experiments. In Experiment 1, oocytes (n = 3,917) were fertilized in vitro and cultured with 0, 50, 100, or 200 ?M trans-10, cis-12 (t10, c12 CLA). In Experiment 2, fertilized oocytes (n = 2,131) were cultured with 100 ?M t10, c12 or cis-9, trans-11 (c9, t11 CLA), or a combination of both isomers. The embryos were vitrified at the blastocyst (BL) or the expanded blastocyst (EB) stage. In Experiment 3, oocytes (n = 1,720) were fertilized and cultured with or without 100 ?M t10, c12 CLA, and the blastocysts were vitrified or frozen. Blastocyst development rate as well as the rates of re-expansion and hatching after thawing was recorded. Moreover, the mean cell number and mRNA expression of acetyl-CoA carboxylase (ACC1) and stearoyl-CoA desaturase (SCD1) as well as fatty acid synthase (FASN) multienzyme complex were determined. In Experiment 1, the highest concentration of t10, c12 CLA that did not reduce blastocyst development rate was 100 ?M. In Experiment 2, the rates of re-expansion and hatching among the EBs obtained through IVP after supplementation with t10, c12 CLA (73.1% and 57.7%), with c9, t11 CLA (80.0% and 68.6%), with the combination (78.3% and 52.2%), and with the control group (85.4% and 58.3%) were similar. At the BL stage, the rates of re-expansion and hatching were lower than those at the EB stage, and CLA combination allowed a hatching rate (8.0%) lower than that observed in the control group (40.0%). In Experiment 3, the hatching rates for vitrified EBs (vitrified control; 67.4%) and vitrified CLA EBs (65.8%) were higher than those obtained for frozen EBs, exposed (13.3%) or not exposed (28.6%) to CLA. In addition, in Experiment 3, the hatching rate was higher at the EB stage in vitrified groups, while the rates of BL and EB were similar in frozen groups, thus proving that vitrification was more efficient than freezing for IVP bovine embryos. In Experiment 3, CLA isomer t10, C12 did not influence the embryonic cell number or mRNA expression of ACC1 and SCD1 enzymes, but decreased the mRNA expression of FASN. In conclusion, 100 ?M CLA did not affect subsequent embryonic development. However, neither CLA isomer improved the cryotolerance of IVP bovine embryos.

Effect of the cryopreservation method used, the embryonic stage and the use of conjugated linoleic acid isomers on the cryotolerance of in vitro-produced bovine embryos

&lt;p&gt;Conjugated linoleic acid (CLA) might be able to improve the cryotolerance of &lt;em&gt;in vitro-&lt;/em&gt;produced (IVP) embryos. The effect of two CLA isomers on the cryotolerance of bovine IVP embryos, as well as that of the stage of embryonic development and the method used for cryopreservation was evaluated by three experiments. In Experiment 1, oocytes (n = 3,917) were fertilized &lt;em&gt;in vitro &lt;/em&gt;and cultured with 0, 50, 100, or 200 ?M &lt;em&gt;trans-&lt;/em&gt;10&lt;em&gt;, cis-&lt;/em&gt;12 (t10, c12 CLA). In Experiment 2, fertilized oocytes (n = 2,131) were cultured with 100 ?M t10, c12 or &lt;em&gt;cis-&lt;/em&gt;9&lt;em&gt;, trans-&lt;/em&gt;11 (c9&lt;em&gt;, &lt;/em&gt;t11 CLA), or a combination of both isomers. The embryos were vitrified at the blastocyst (BL) or the expanded blastocyst (EB) stage. In Experiment 3, oocytes (n = 1,720) were fertilized and cultured with or without 100 ?M t10, c12 CLA, and the blastocysts were vitrified or frozen. Blastocyst development rate as well as the rates of re-expansion and hatching after thawing was recorded. Moreover, the mean cell number and mRNA expression of acetyl-CoA carboxylase (ACC1) and stearoyl-CoA desaturase (SCD1) as well as fatty acid synthase (FASN) multienzyme complex were determined. In Experiment 1, the highest concentration of t10, c12 CLA that did not reduce blastocyst development rate was 100 ?M. In Experiment 2, the rates of re-expansion and hatching among the EBs obtained through IVP after supplementation with t10, c12 CLA (73.1% and 57.7%), with c9, t11 CLA (80.0% and 68.6%), with the combination (78.3% and 52.2%), and with the control group (85.4% and 58.3%) were similar. At the BL stage, the rates of re-expansion and hatching were lower than those at the EB stage, and CLA combination allowed a hatching rate (8.0%) lower than that observed in the control group (40.0%). In Experiment 3, the hatching rates for vitrified EBs (vitrified control; 67.4%) and vitrified CLA EBs (65.8%) were higher than those obtained for frozen EBs, exposed (13.3%) or not exposed (28.6%) to CLA. In addition, in Experiment 3, the hatching rate was higher at the EB stage in vitrified groups, while the rates of BL and EB were similar in frozen groups, thus proving that vitrification was more efficient than freezing for IVP bovine embryos. In Experiment 3, CLA isomer t10, C12 did not influence the embryonic cell number or mRNA expression of ACC1 and SCD1 enzymes, but decreased the mRNA expression of FASN. In conclusion, 100 ?M CLA did not affect subsequent embryonic development. However, neither CLA isomer improved the cryotolerance of IVP bovine embryos.&lt;/p&gt;

Conjugated linoleic acid isomers strongly improve the redox status of bovine mammary epithelial cells (BME-UV1)

Some studies have shown the protective effects of conjugated linoleic acid (CLA) isomers against oxidative stress and lipid peroxidation in animal models, but no information is available about CLA and changes in oxidative status of the bovine mammary gland. The objectives of the study were to assess in vitro the effect of CLA on the cellular antioxidant response of bovine mammary cells, to examine whether CLA isomers could play a role in cell protection against the oxidative stress, and to study the molecular mechanism involved. For the study, BME-UV1 cells, a bovine mammary epithelial cell line, were used as the experimental model. The BME-UV1 cells were treated with complete medium containing 50 µM cis-9,trans-11 CLA (c9,t11 CLA), trans-10,cis-12 CLA (t10,c12 CLA), and CLA mixture (1:1, cis-9,trans-11: trans-10,cis-12 CLA). To monitor cellular uptake of CLA isomers, cells and culture medium were collected at 0, 3, and 48h from CLA addition for lipid extraction and fatty acid analyses. To assess the cellular antioxidant response, glutathione (GSH/GSSH), NADPH, and γ-glutamyl-cysteine ligase activity was measured after 48h from addition of CLA. Cytoplasmic superoxide dismutase, glutathione peroxidase, glutathione S-transferase, and glutathione reductase activities and mRNA were also determined. Intracellular reactive oxygen species and thiobarbituric acid reactive substance production were assessed in cells supplemented with CLA isomers. Cell viability after 3h to H2O2 exposure was assessed to evaluate and to compare the potential protection of different CLA isomers against H2O2-induced oxidative stress. Mammary cells readily picked up all CLA isomers, their accumulation was time dependent, and main metabolites at 48h are two 18:3 isomers. The CLA treatment induced an intracellular GSH increase, matched by high concentration of NADPH, and an increase of γ-glutamyl-cysteine ligase activity mainly in cells treated with the t10,c12 CLA isomer. The CLA isomer treatment of bovine mammary cells increased superoxide dismutase, glutathione peroxidase, and glutathione S-transferase activity and decreased glutathione reductase activity, but no changes in gene expression of these antioxidant enzymes were observed. Cells supplemented with CLA isomers showed a reduction in intracellular reactive oxygen species and thiobarbituric acid reactive substance levels. All CLA isomers were able to enhance cell resistance against H2O2-induced oxidative stress. These suggest an antioxidant role of CLA, in particular of t10,c12 CLA, by developing a significantly high redox status in cells.

Evaluation of the Impact of Ruminant Trans Fatty Acids on Human Health: Important Aspects to Consider

The definition and evaluation of trans fatty acids (TFA) with regard to foodstuffs and health hazard are not consistent. Based on the current situation, the term should be restricted only to TFA with isolated double bonds in trans-configuration. Conjugated linoleic acids (CLA) should be separately assessed. Ideally, the origin of the consumed fat should be declared, i.e., ruminant TFA (R-TFA) and industrial TFA (non-ruminant; I-TFA). In ruminant fat, more than 50% of R-TFA consists of vaccenic acid (C18:1 t11). In addition, natural CLA, i.e., c9,t11 CLA is also present. Both are elevated in products from organic farming. In contrast to elaidic acid (t9) and t10, which occur mainly in partially hydrogenated industrial fat, t11 is partially metabolized into c9,t11 CLA via Δ9-desaturation. This is the major metabolic criterion used to differentiate between t11 and other trans C18:1. t11 indicates health beneficial effects in several studies. Moreover, CLA in milk fat is associated with the prevention of allergy and asthma. An analysis of the few studies relating to R-TFA alone makes clear that no convincing adverse physiological effect can be attributed to R-TFA. Only extremely high R-TFA intakes cause negative change in blood lipids. In conclusion, in most European countries, the intake of R-TFA is assessed as being low to moderate. Restriction of R-TFA would unjustifiably represent a disadvantage for organic farming of milk.

Milk Yield, Composition, and Fatty Acid Profile in Dairy Cows Fed a High-concentrate Diet Blended with Oil Mixtures Rich in Polyunsaturated Fatty Acids.

To evaluate the effects of feeding linseed oil or/and sunflower oil mixed with fish oil on milk yield, milk composition and fatty acid (FA) profiles of dairy cows fed a high-concentrate diet, 24 crossbred primiparous lactating dairy cows in early lactation were assigned to a completely randomized design experiment. All cows were fed a high-concentrate basal diet and 0.38 kg dry matter (DM) molasses per day. Treatments were composed of a basal diet without oil supplement (Control), or diets of (DM basis) 3% linseed and fish oils (1:1, w/w, LSO-FO), or 3% sunflower and fish oils (1:1, w/w, SFO-FO), or 3% mixture (1:1:1, w/w) of linseed, sunflower, and fish oils (MIX-O). The animals fed SFO-FO had a 13.12% decrease in total dry matter intake compared with the control diet (p<0.05). No significant change was detected for milk yield; however, the animals fed the diet supplemented with SFO-FO showed a depressed milk fat yield and concentration by 35.42% and 27.20%, respectively, compared to those fed the control diet (p<0.05). Milk c9, t11-conjugated linoleic acid (CLA) proportion increased by 198.11% in the LSO-FO group relative to the control group (p<0.01). Milk C18:3n-3 (ALA) proportion was enhanced by 227.27% supplementing with LSO-FO relative to the control group (p<0.01). The proportions of milk docosahexaenoic acid (DHA) were significantly increased (p<0.01) in the cows fed LSO-FO (0.38%) and MIX-O (0.23%) compared to the control group (0.01%). Dietary inclusion of LSO-FO mainly increased milk c9, t11-CLA, ALA, DHA, and n-3 polyunsaturated fatty acids (PUFA), whereas feeding MIX-O improved preformed FA and unsaturated fatty acids (UFA). While the lowest n-6/n-3 ratio was found in the LSO-FO, the decreased atherogenecity index (AI) and thrombogenicity index (TI) seemed to be more extent in the MIX-O. Therefore, to maximize milk c9, t11-CLA, ALA, DHA, and n-3 PUFA and to minimize milk n-6/n-3 ratio, AI and TI, an ideal supplement would appear to be either LSO-FO or MIX-O.

Gender differences in the myocardial response to dietary CLA isomers during diabetes

This study was undertaken to examine if conjugated linoleic acid (CLA) isomers c9,t11 and t10,c12, provide protection against cardiac dysfunction in diabetic male and female rats. Diabetes was induced by an intravenous injection of streptozotocin (65 mg/kg body weight) in male and female rats. Four wks after the induction of diabetes, the animals were treated daily for 4 wks with or without 0.5% of each CLA isomer by oral gavage. Eight wks diabetes was associated with elevated levels of plasma total cholesterol, HDL-cholesterol, triglycerides and glucose as well as depressed rate of cardiac relaxation (-dP/dt) in both male and female animals. However, unlike females, male diabetic rats showed an increase in heart weight: body weight ratio and decreased rates of cardiac contraction (+dP/dt) and fractional shortening (FS). Both CLA isomers improved the lipid profile in male diabetic rats, whereas only CLA c9,t11 isomer improved the lipid profile in females. CLA intervention did not affect blood glucose levels in male or female diabetic animals. While CLA c9,t11 isomer improved ± dP/dt in the male rats, a deterioration of +dP/dt and -dP/dt in the female diabetic rats was observed. Although FS was normalized by both CLA isomers in males, CLA t10,c12 isomer depressed FS in the female diabetic rats. CLA treatment normalized GLUT 4 gene expression levels, but markedly increased insulin receptor gene expression in the heart of male diabetic rats. These data suggest that, unlike females, improved myocardial function in male diabetic rats in response to CLA may be related to a favorable shift in myocardial energetics.

Trans-10,cis-12-conjugated linoleic acid worsens renal pathology and alters cyclooxygenase derived oxylipins in obesity-associated nephropathy

Dietary conjugated linoleic acid (CLA) reduces indicators of early renal disease progression and the associated elevated cyclooxygenase (COX) levels in young obese rats with obesity-associated nephropathy (OAN). Therefore, renal function and injury and COX and its metabolites were assessed in obese fa/fa Zucker rats with more advanced renal disease. Obese rats at 16weeks of age were provided with either cis(c)9, trans(t)11 (fa/fa-9,11) or t10,c12 (fa/fa-10,12) CLA for 8weeks, and compared to lean (lean-CTL) and obese (fa/fa-CTL) rats provided the control diet without CLA. Obese rats displayed significantly reduced renal function and increased renal injury compared to lean rats. In the obese rat groups, glomerular hypertrophy was reduced in both CLA-supplemented groups. While all other measures of renal function or injury were not different in fa/fa-9,11 compared to fa/fa-CTL rats, the fa/fa-10,12 rats had greater renal hypertrophy, glomerular fibrosis, fibrosis, tubular casts and macrophage infiltration compared to the fa/fa-CTL and fa/fa-9,11 groups. The fa/fa-10,12 group also had elevated levels of renal COX1, which was associated with increased levels of two oxylipins produced by this enzyme, 6-keto-prostaglandin F1α, and thromboxane B2. Renal linoleic acid and its lipoxygenase products also were lower in obese compared to lean rats, but CLA supplementation had no effect on these or any other lipoxygenase oxylipins. In summary, supplementation with c9,t11 CLA did not improve more advanced OAN and t10,c12 CLA worsened the renal pathology. Altered production of select COX1 derived oxylipins was associated with the detrimental effect of the t10,c12 isomer.

In vitro study of the bioavailability of fatty acids in cow milk containing conjugated linoleic acids produced in vivo or added in synthetic form

The intestinal absorption of fatty acids from milk, especially conjugated linoleic acids (CLA), was evaluated using an in vitro simulator. Milk was enriched with c9,t11 CLA by feeding a cow a diet containing 4% safflower oil or by emulsifying synthetic CLA in the form of free fatty acid or triacylglycerol, then standardized to 1.0% or 3.25% fat. Fatty acid bioavailability depended on chain length, presence of double bonds, and the percentage of fat. Absorption was more efficient in the presence of 1.0% fat. The bioavailability of c9,t11 CLA at 3.25% fat was 89% in the milk from the cow fed the safflower-oil diet, and 85% and 71% in milk enriched with synthetic free CLA and synthetic CLA in the form of triacylglycerol, respectively. At 1.0% fat, these values were 90%, 99% and 96%, respectively, suggesting that bioavailability of CLA in milk is affected by the percentage of fat present.