Conjugated linoleic acid and atherosclerosis in rabbits

Effect of pomegranate seed oil on egg production, egg quality and yolk fatty acid deposition in laying hen

BACKGROUND

Pomegranate seed oil (PSO) contains punicic acid as well as conjugated linolenic acid isomers, including α-eleostearic and catalpic acids, along with phytosterols, especially β-sitosterol, campesterol and stigmasterol, with lipotropic impact and egg fortifying effect in laying hens.

OBJECTIVES

The present experiment was designed to examine the effects of PSO on egg production, egg quality, blood lipids and yolk fatty acid deposition in laying hens.

METHODS

A total of 360 Hy-line laying hens (w-80), at 25 weeks of age, were randomly allotted to five dietary treatments in a completely randomized design during a 10-week period. Experimental treatments consisted of a basal diet or supplementation of 1, 2, 3 and 4 g PSO/kg to basal diet. Performance indicators and fatty acid composition of egg yolk were evaluated during different experimental periods. Blood lipid attributes were evaluated at the end of the experiment.

RESULTS

Dietary supplementation of 4 g PSO/kg feed increased daily feed intake and egg production rate of laying hens (p < 0.05). There was not any significant influence of experimental treatments on egg quality, whereas an increasing trend observed in egg yolk colour of hens received dietary graded levels of PSO. Dietary supplemental 4 g/kg PSO increased the proportion of yolk poly-unsaturated fatty acid (PUFA) concentration (p < 0.05). Furthermore, the PUFA to saturated fatty acid ratio increased after dietary supplementation of 1 or 4 g/kg PSO (p < 0.05). Serum concentration of cholesterol, triacylglycerol and low-density lipoprotein decreased in response to the supplementation of more than 3 g PSO/kg in the feed (p < 0.05).

CONCLUSIONS

In conclusion, dietary supplementation with 4 g/kg PSO improved production rate and decreased blood lipids in laying hens. Moreover, dietary supplemental PSO modified yolk fatty acid deposition without detrimental effects on the egg quality.

Conjugated Linoleic Acid-Mediated Connexin-43 Remodeling and Sudden Arrhythmic Death in Myocardial Infarction

Connexin 43 (Cx43) is expressed in the left and right ventricles and is primarily responsible for conducting physiological responses in microvasculature. Studies have demonstrated that NADPH oxidase (NOX) enzymes are essential in cardiac redox biology and are responsible for the generation of reactive oxygen species (ROS). NOX2 is linked to left ventricular remodeling following myocardial infarction (MI). It was hypothesized that conjugated linoleic acid (cLA) treatment increases NOX-2 levels in heart tissue and disrupts connexins between the myocytes in the ventricle. Data herein demonstrate that cLA treatment significantly decreases survival in a murine model of MI. The observance of cLA-induced ventricular tachyarrhythmia's (VT) led to the subsequent investigation of the underlying mechanism in this MI model. Mice were treated with cLA for 12 h, 24 h, 48 h, or 72 h to determine possible time-dependent changes in NOX and Cx43 signaling pathways in isolated left ventricles (LV) extracted from cardiac tissue. The results suggest that ROS generation, through the stimulation of NOX2 in the LV, triggers a decrease in Cx43 levels, causing dysfunction of the gap junctions following treatment with cLA. This cascade of events may initiate VT and subsequent death during MI. Taken together, individuals at risk of MI should use caution regarding cLA consumption.

Multiple biological activities and biosynthesis mechanisms of specific conjugated linoleic acid isomers and analytical methods for prospective application

Conjugated linoleic acid (CLA) is a collective term for the octadecadienoic acid isomers containing conjugated double bonds. This article reviewed CLA isomers from biological activities, biosynthesis mechanisms and analytical methods. The biological activities of CLA isomers in anti-obesity, cardiovascular protection, diabetes management and anti-cancer in vitro and in vivo were mainly reviewed. More attention has been paid to the production of the specific CLA isomer due to its biological activity. The biosynthesis methods of CLA isomers, such as dietary modification in ruminants and fermentation by microorganisms & enzymes, were systematically introduced. A rapid, accurate and economic analysis method will promote the research in both biological activities and biosynthesis mechanisms of CLA isomers. The merits of UV spectrometry, GC, HPLC, MS and CE used in the analysis of CLA isomers were also compared in detail. This paper aims to put into perspective the current status and future trends on CLA isomers.

Conjugated Linoleic Acids Have Anti-Inflammatory Effects in Cultured Endothelial Cells

Conjugated linoleic acid (CLA) isomers may have a role in preventing atherosclerosis through the modulation of inflammation, particularly of the endothelium. However, whether low concentrations of CLAs are able to affect basal unstimulated endothelial cell (EC) responses is not clear. The aim of this study was to evaluate the effects of two CLAs (cis-9, trans-11 (CLA9,11) and trans-10, cis-12 (CLA10,12)) on the basal inflammatory responses by ECs. EA.hy926 cells (HUVEC lineage) were cultured under standard conditions and exposed to individual CLAs for 48 h. Both CLAs were incorporated into ECs in a dose-dependent manner. CLA9,11 (1 μM) significantly decreased concentrations of MCP-1 (p < 0.05), IL-6 (p < 0.05), IL-8 (p < 0.01) and RANTES (p < 0.05) in the culture medium. CLA10,12 (10 μM) decreased the concentrations of MCP-1 (p < 0.05) and RANTES (p < 0.05) but increased the concentration of IL-6 (p < 0.001). At 10 μM both CLAs increased the relative expression of the NFκβ subunit 1 gene (p < 0.01 and p < 0.05, respectively), while decreasing the relative expression of PPARα (p < 0.0001), COX-2 (p < 0.0001) and IL-6 (p < 0.0001) genes. CLA10,12 increased the relative expression of the gene encoding IκK-β at 10 μM compared with CLA9,11 (p < 0.05) and increased the relative expression of the gene encoding IκBα at 1 and 10 μM compared with linoleic acid (both p < 0.05). Neither CLA affected the adhesion of monocytes to ECs. These results suggest that low concentrations of both CLA9,11 and CLA10,12 have modest anti-inflammatory effects in ECs. Thus, CLAs may influence endothelial function and the risk of vascular disease. Nevertheless, at these low CLA concentrations some pro-inflammatory genes are upregulated while others are downregulated, suggesting complex effects of CLAs on inflammatory pathways.

Dietary supplements for obesity

Obesity and associated complications including diabetes, cardiometabolic dysfunction, disability, malignancy and premature mortality are considered epidemic. Research on obesity is therefore of worldwide importance. The development of obesity is a multifactorial phenomenon with contributions from biological, behavioral, genetic and environmental factors. Obesity and its associated issues require various lifestyle modifications and treatment options such medication, exercise, diet, surgery, pharmacological therapy and dietary supplements. Dietary supplements are considered an attractive alternative to traditional therapy due to their low toxicity profile and their accessibility to the general population. Dietary supplements may include one or more dietary ingredients. In this narrative review, we analyze the effects on obesity and obesity-related issues of various natural components. For example, there are a myriad of supplements that have been used as dietary supplements for weight loss such as minerals, vitamins, amino acids, metabolites, herbs, and plant extracts. This narrative review aims to present the benefits and side-effects of several ingredients of dietary supplements for weight loss and treatment of obesity. In particular, the mechanism of action, results of clinical trials, and possible side effects will be presented for the following ingredients: β-Glucans, bitter orange, calcium, vitamin D, chitosan, chromium, cocoa, coleus forskohlii, conjugate linoleic acid, ephedra sinica, fucoxanthin, garcinia cambogia, glucomannan, green coffee, green tea, guar gum, raspberry, hoodia gordonii, irvingia gabonensis, phenylpropylamine, pyruvate, white kidney bean.

Pre-Partum Supplementation with Polyunsaturated Fatty Acids on Colostrum Characteristics and Lamb Immunity and Behavior after a Mild Post-Weaning Aversive Handling Period

We studied the effect of pre-natal supplementation with n-3 α-linolenic acid (ALA) combined with a tannin-rich forage on colostrum composition and immunological quality and whether these changes had advantageous effects on lambs’ survival and stress reaction to a post-weaning stressor. Forty-eight Latxa ewes were fed during the last five weeks of pregnancy with two experimental diets: a control diet based on a neutral concentrate and forage (tall fescue hay; CO-FES), and a supplemented diet based on polyunsaturated (PUFA)-rich concentrate and tanniferous forage (sainfoin; ALA-SAIN). After parturition, twenty ewes had their blood and colostrum sampled, and their lambs were monitored until post-weaning. Lambs were afterwards subjected to (i) an aversive handling period (AHP) followed by a behavioral assessment and (ii) inflammatory and lymphocyte proliferation challenge. Feeding ALA-SAIN resulted in changes in colostrum fatty acid composition, specifically higher α-linoleic acid (p < 0.001), conjugate linoleic acid (p = 0.005), vaccenic acid (p = 0.006) and long-chain n-3 PUFA (p = 0.004). Pre-partum nutrition did not affect lamb immunoglobulin (Ig) G apparent efficacy absorption, but circulating IgG tended to be higher (p = 0.054) in ALA-SAIN lambs. ALA-SAIN lambs interacted more frequently with other lambs (p = 0.002), whereas ALA-SAIN females spent more time closer to other lambs (p < 0.001). Plasma cortisol was higher (p = 0.047) and plasma interleukin (IL)-2 lower (p = 0.003) in CO-FES lambs. This research highlights the importance of prenatal nutrition on the immune system stimulation and lambs’ behavior as a strategy to improve lambs’ health and welfare during early life.

Differential Inflammatory Responses in Cultured Endothelial Cells Exposed to Two Conjugated Linoleic Acids (CLAs) under a Pro-Inflammatory Condition

Conjugated linoleic acid (CLA) isomers have been shown to possess anti-atherosclerotic properties, which may be related to the downregulation of inflammatory pathways in different cell types, including endothelial cells (ECs). However, whether different CLA isomers have different actions is not entirely clear, with inconsistent reports to date. Furthermore, in cell culture studies, CLAs have often been used at fairly high concentrations. Whether lower concentrations of CLAs are able to affect EC responses is not clear. The aim of this study was to evaluate the effects of two CLAs (cis-9, trans-11 (CLA9,11) and trans-10, cis-12 (CLA10,12)) on the inflammatory responses of ECs. ECs (EA.hy926 cells) were cultured under standard conditions and exposed to CLAs (1 to 50 μM) for 48 h. Then, the cells were cultured for a further 6 or 24 h with tumour necrosis factor alpha (TNF-α, 1 ng/mL) as an inflammatory stimulant. ECs remained viable after treatments with 1 and 10 μM of each CLA, but not after treatment with 50 μM of CLA10,12. CLAs were incorporated into ECs in a concentration-dependent manner. CLA10,12 increased the levels of ICAM-1, IL-6, and RANTES in the culture medium, while CLA9,11 had null effects. Both CLAs (1 μM) decreased the appearance of NFκB1 mRNA, but only CLA9,11 maintained this downregulation at 10 μM. CLA10,12 had no effect on THP-1 cell adhesion to ECs while significantly decreasing the percentage of ECs expressing ICAM-1 and also levels of ICAM-1 expression per cell when used at 10 µM. Although CLA9,11 did not have any effect on ICAM-1 cell surface expression, it reduced THP-1 cell adhesion to the EA.hy926 cell monolayer at both concentrations. In summary, CLA10,12 showed some pro-inflammatory effects, while CLA9,11 exhibited null or anti-inflammatory effects. The results suggest that each CLA has different effects in ECs under a pro-inflammatory condition, highlighting the need to evaluate the effects of CLA isomers independently.

Suppression of amyloid-β secretion from neurons by cis-9, trans-11-octadecadienoic acid, an isomer of conjugated linoleic acid

Two common conjugated linoleic acids (LAs), cis-9, trans-11 CLA (c9,t11 CLA) and trans-10, cis-12 CLA (t10,c12 CLA), exert various biological activities. However, the effect of CLA on the generation of neurotoxic amyloid-β (Aβ) protein remains unclear. We found that c9,t11 CLA significantly suppressed the generation of Aβ in mouse neurons. CLA treatment did not affect the level of β-site APP-cleaving enzyme 1 (BACE1), a component of active γ-secretase complex presenilin 1 amino-terminal fragment, or Aβ protein precursor (APP) in cultured neurons. BACE1 and γ-secretase activities were not directly affected by c9,t11 CLA. Localization of BACE1 and APP in early endosomes increased in neurons treated with c9,t11 CLA; concomitantly, the localization of both proteins was reduced in late endosomes, the predominant site of APP cleavage by BACE1. The level of CLA-containing phosphatidylcholine (CLA-PC) increased dramatically in neurons incubated with CLA. Incorporation of phospholipids containing c9,t11 CLA, but not t10,c12 CLA, into the membrane may affect the localization of some membrane-associated proteins in intracellular membrane compartments. Thus, in neurons treated with c9,t11 CLA, reduced colocalization of APP with BACE1 in late endosomes may decrease APP cleavage by BACE1 and subsequent Aβ generation. Our findings suggest that accumulation of c9,t11 CLA-PC/LPC in neuronal membranes suppresses production of neurotoxic Aβ in neurons.

Punicic Acid Triggers Ferroptotic Cell Death in Carcinoma Cells

Plant-derived conjugated linolenic acids (CLnA) have been widely studied for their preventive and therapeutic properties against diverse diseases such as cancer. In particular, punicic acid (PunA), a conjugated linolenic acid isomer (C18:3 c9t11c13) present at up to 83% in pomegranate seed oil, has been shown to exert anti-cancer effects, although the mechanism behind its cytotoxicity remains unclear. Ferroptosis, a cell death triggered by an overwhelming accumulation of lipid peroxides, has recently arisen as a potential mechanism underlying CLnA cytotoxicity. In the present study, we show that PunA is highly cytotoxic to HCT-116 colorectal and FaDu hypopharyngeal carcinoma cells grown either in monolayers or as three-dimensional spheroids. Moreover, our data indicate that PunA triggers ferroptosis in carcinoma cells. It induces significant lipid peroxidation and its effects are prevented by the addition of ferroptosis inhibitors. A combination with docosahexaenoic acid (DHA), a known polyunsaturated fatty acid with anticancer properties, synergistically increases PunA cytotoxicity. Our findings highlight the potential of using PunA as a ferroptosis-sensitizing phytochemical for the prevention and treatment of cancer.

A Systematic Review of Dietary Supplements and Alternative Therapies for Weight Loss

OBJECTIVE

Dietary supplements and alternative therapies are commercialized as a panacea for obesity/weight gain as a result of the minimal regulatory requirements in demonstrating efficacy. These products may indirectly undermine the value of guideline-driven obesity treatments. Included in this study is a systematic review of the literature of purported dietary supplements and alternative therapies for weight loss.

METHODS

A systematic review was conducted to evaluate the efficacy of dietary supplements and alternative therapies for weight loss in participants aged ≥18 years. Searches of Medline (PubMed), Cochrane Library, Web of Science, CINAHL, and Embase (Ovid) were conducted. Risk of bias and results were summarized qualitatively.

RESULTS

Of the 20,504 citations retrieved in the database search, 1,743 full-text articles were reviewed, 315 of which were randomized controlled trials evaluating the efficacy of 14 purported dietary supplements, therapies, or a combination thereof. Risk of bias and sufficiency of data varied widely. Few studies (n = 52 [16.5%]) were classified as low risk and sufficient to support efficacy. Of these, only 16 (31%) noted significant pre/post intergroup differences in weight (range: 0.3-4.93 kg).

CONCLUSIONS

Dietary supplements and alternative therapies for weight loss have a limited high-quality evidence base of efficacy. Practitioners and patients should be aware of the scientific evidence of claims before recommending use.

Draft genome sequence of Lactobacillus delbrueckii subsp. bulgaricus LBP UFSC 2230: a tool for preliminary identification of enzymes involved in CLA metabolism

Several Lactobacillus ssp. are recognized as potential conjugated linoleic acid (CLA) producers. We have previously reported the ability of a range of Lactobacillus delbrueckii subsp. bulgaricus strains to produce CLA in fermented milk, being a potential candidate for the fermented dairy food chain. This study reports the draft genome sequence of L. bulgaricus strain LBP UFSC 2230, isolated from Italian Grana Padano cheese. Draft genome sequence originated in a total of 4,310,842 paired-end reads that were quality trimmed and assembled into 135 contigs with a total length of 604,745,873 bp, including 2086 protein coding genes and an average GC content of 49.7%. Draft genome sequence represents an important tool to identify the enzymes involved in this strain's CLA metabolism. We identified a gene encoding an enzyme involved in biohydrogenation of linoleic acid pathway, oleate hydratase.

Conjugated Fatty Acids in Muscle Food Products and Their Potential Health Benefits: A Review

Conjugated fatty acids (CFAs) are a group of positional and geometric isomers of polyunsaturated fatty acids (PUFAs) with conjugated double bonds. There are several subgroups of CFAs including conjugated linoleic acids (CLAs), conjugated linolenic acids (CLNAs), conjugated eicosapentaenoic acids (CEPAs), and conjugated docosahexaenoic acids (CDHAs). CFAs, especially CLAs, have been studied in recent years both for their health benefits and factors that affect their level in muscle food products. CFAs have been reported in numerous studies as having antitumor, antiobesity, antidiabetes, anticardiovascular disease, and modulating immune system effects. These biological activies are involved in changes of lipid peroxidation and energy expenditure, as well as inhibitory effects on the hormone receptor, lipid metabolism, lipoprotein lipase activity, and adiponectin production. A large body of studies has revealed that the diet, processing, storage conditions, slaughter season, and age are common factors that affect CFA content in muscle food products, as detailed in this review. Recommendations are made regarding animal farming and meat product processing to obtain high CFA content meat products and to optimize the benefits of CFA for health promotion.

Effects of Combined Supplementation of Conjugated Linoleic Acid, Methionine Chromium, Betaine, and Cysteamine on Meat Tenderness of Rats

A systemic design was carried out to investigate the optimal combination of BET, Met-Cr, CLA, and CS for improving the meat tenderness in rats. A total of 104 six-week old male Sprague-Dawley rats were randomly assigned to 13 treatments with 4 replicates of 2 rats each. The experiments lasted for 5 weeks. The results showed that inclusion of Met-Cr decreased the contents of intramuscular fat (IMF), fat among muscle cells, and lipid droplets inside muscle cells (P < 0.05), and inclusion of CLA or Met-Cr increased the contents of IMF, fat among muscle cells, and lipid droplets inside muscle cells (P < 0.05). CS increased the contents of total collagen (TC) and soluble collagen (SC), and CLA decreased the contents of TC and SC (P < 0.05). The combination of BET and CLA increased IMF and SC contents and decreased TC contents (P < 0.05). The combination of BET and CS could increase fat contents among muscle cells and decrease TC and SC contents (P < 0.05). The combination of CLA and Met-Cr decreased IMF contents (P < 0.05). The combination of CLA and CS, as well as Met-Cr and CS, decreased fat contents among muscle cells (P < 0.05). These combinations may regulate lipogenesis and decrease the deposition of fat in muscles. There existed a significant positive correlation between IMF and SC content, which might indicate that IMF content improves meat's tenderness partly by increasing SC content in muscle.

Spruce Galactoglucomannan-Stabilized Emulsions Enhance Bioaccessibility of Bioactive Compounds

The increasing public awareness of health and sustainability has prompted the development of functional foods rich in health-promoting ingredients. Processing technologies and sustainable multifunctional ingredients are needed for structuring these formulations. Spruce galactoglucomannan (GGM), the main hemicelluloses in softwood cell walls, are an abundantly available, emerging sustainable food hydrocolloid that have the ability to efficiently emulsify and stabilize oil-in-water emulsions. In this study, we illustrate how this lignocellulosic stabilizer affects the digestion of polyunsaturated fatty acids (PUFAs) in vitro. A 100% decrease in the initial TAG content was observed during the in vitro digestion, suggesting that complete hydrolysis of the TAGs was achieved by the digestive enzymes. Besides, no release of mono-, di-, and oligosaccharides or phenolic compounds from GGM was detected. Our results demonstrate that the GGM-stabilized emulsion could potentially deliver lipophilic bioactive ingredients and enhance their bioaccessibility. In addition, this bio-stabilizer itself would remain stable in the upper gastrointestinal track and serve as a prebiotic for gut microbiota. We anticipate GGM to complement or even replace many of the conventional carriers of bioactive components in future health care products and functional foods.

Trans-10, cis-12 conjugated linoleic acid reduces milk fat content and lipogenic gene expression in the mammary gland of sows without altering litter performance

Trans-10, cis-12 conjugated linoleic acid (CLA) decreases milk fat synthesis in lactating sows and involves, at least in part, the down-regulation of lipogenic genes. The objective was to evaluate the effect of CLA on milk composition and lipogenic gene expression. Twenty multiparous sows were randomly assigned to one of the two treatments for 18 d (from day 7 to day 25 of lactation): (1) control (no CLA added) and (2) 1 % of CLA mixed into the ration. CLA treatment decreased milk fat and protein content by 20 % (P = 0·004) and 11 % (P = 0·0001), respectively. However, piglet weight did not differ between treatments (P = 0·60). Dietary CLA increased the concentration of SFA in milk fat by 16 % (P < 0·0001) and decreased MUFA by 17·6 % (P < 0·0001). In the mammary gland, CLA reduced gene expression of acetyl-CoA carboxylase-α by 37 % (P = 0·003), fatty acid synthase by 64 % (P = 0·002), stearoyl-CoA desaturase 1 by 52 % (P = 0·003), lipoprotein lipase by 26 % (P = 0·03), acyl glycerol phosphate acyltransferase 6 by 15 % (P = 0·02) and diacylglycerol acyltransferase 1 by 27 % (P = 0·02), whereas the expression of fatty acid binding protein 3 was not altered by CLA treatment (P = 0·09). Mammary expression of casein-β and α-lactalbumin was reduced by CLA by 68 % (P = 0·0004) and 62 % (P = 0·005), respectively. Additionally, CLA had no effect on the expression of lipogenic genes evaluated in adipose tissue. In summary, CLA reduced milk fat content without negatively affecting litter performance and it affected mammary expression of genes involved in all lipogenic pathways studied.

Nutrigenomic effect of conjugated linoleic acid on growth and meat quality indices of growing rabbit

Conjugated linoleic acid was detected in rabbit caecotrophs, due to the presence of microbial lipid activity in rabbit cecum. However, the effect of CLA as a functional food in growing rabbit is not well established. Therefore, this study was conducted to determine the effect of CLA on production, meat quality, and its nutrigenomic effect on edible parts of rabbit carcass including skeletal muscle, liver, and adipose tissue. Therefore, seventy five weaned V-Line male rabbits, 30 days old, were randomly allocated into three dietary treatments receiving either basal control diet, diet supplemented with 0.5% (CLAL), or 1% CLA (CLAH). Total experimental period (63 d) was segmented into 7 days adaptation and 56 days experimental period. Dietary supplementation of CLA did not alter growth performance, however, the fat percentage of longissimus lumborum muscle was decreased, with an increase in protein and polyunsaturated fatty acids (PUFA) percentage. Saturated fatty acids (SFA) and mono unsaturated fatty acids (MUFA) were not increased in CLA treated groups. There was tissue specific sensing of CLA, since subcutaneous adipose tissue gene expression of PPARA was downregulated, however, CPT1A tended to be upregulated in liver of CLAL group only (P = 0.09). In skeletal muscle, FASN and PPARG were upregulated in CLAH group only (P ≤0.01). Marked cytoplasmic vacuolation was noticed in liver of CLAH group without altering hepatocyte structure. Adipocyte size was decreased in CLA fed groups, in a dose dependent manner (P <0.01). Cell proliferation determined by PCNA was lower (P <0.01) in adipose tissue of CLA groups. Our data indicate that dietary supplementation of CLA (c9,t11-CLA and t10,c12- CLA) at a dose of 0.5% in growing rabbit diet produce rabbit meat rich in PUFA and lower fat % without altering growth performance and hepatocyte structure.

Tissue-dependent effects of cis-9,trans-11- and trans-10,cis-12-CLA isomers on glucose and lipid metabolism in adult male mice

Mixtures of the two major conjugated linoleic acid (CLA) isomers trans-10,cis-12-CLA and cis-9,trans-11-CLA are used as over the counter supplements for weight loss. Because of the reported adverse effects of CLA on insulin sensitivity in some mouse studies, we sought to compare the impact of dietary t10c12-CLA and c9t11-CLA on liver, adipose tissue, and systemic metabolism of adult lean mice. We fed 8 week-old C57Bl/6J male mice with low fat diets (10.5% Kcal from fat) containing 0.8% t10c12-CLA or c9t11-CLA for 9 or 38 days. Diets containing c9t11-CLA had minimal impact on the endpoints studied. However, 7 days after starting the t10c12-CLA diet, we observed a dramatic reduction in fat mass measured by NMR spectroscopy, which interestingly rebounded by 38 days. This rebound was apparently due to a massive accumulation of lipids in the liver, because adipose tissue depots were visually undetectable. Hepatic steatosis and the disappearance of adipose tissue after t10c12-CLA feeding was associated with elevated plasma insulin levels and insulin resistance, compared to mice fed a control diet or c9t11-CLA diet. Unexpectedly, despite being insulin resistant, mice fed t10c12-CLA had normal levels of blood glucose, without signs of impaired glucose clearance. Hepatic gene expression and fatty acid composition suggested enhanced hepatic de novo lipogenesis without an increase in expression of gluconeogenic genes. These data indicate that dietary t10c12-CLA may alter hepatic glucose and lipid metabolism indirectly, in response to the loss of adipose tissue in mice fed a low fat diet.

Conjugated Linoleic Acid Effects on Cancer, Obesity, and Atherosclerosis: A Review of Pre-Clinical and Human Trials with Current Perspectives

Obesity and its comorbidities, including type 2 diabetes and cardiovascular disease, are straining our healthcare system, necessitating the development of novel strategies for weight loss. Lifestyle modifications, such as exercise and caloric restriction, have proven effective against obesity in the short term, yet obesity persists because of the high predilection for weight regain. Therefore, alternative approaches to achieve long term sustainable weight loss are urgently needed. Conjugated linoleic acid (CLA), a fatty acid found naturally in ruminant animal food products, has been identified as a potential anti-obesogenic agent, with substantial efficacy in mice, and modest efficacy in obese human populations. Originally described as an anti-carcinogenic fatty acid, in addition to its anti-obesogenic effects, CLA has now been shown to possess anti-atherosclerotic properties. This review summarizes the pre-clinical and human studies conducted using CLA to date, which collectively suggest that CLA has efficacy against cancer, obesity, and atherosclerosis. In addition, the potential mechanisms for the many integrative physiological effects of CLA supplementation will be discussed in detail, including an introduction to the gut microbiota as a potential mediator of CLA effects on obesity and atherosclerosis.

Comparison of adipose‑ and bone marrow‑derived stem cells in protecting against ox‑LDL‑induced inflammation in M1‑macrophage‑derived foam cells

Adipose‑derived stem cells (ADSCs) and bone marrow‑derived stem cells (BMSCs) are considered to be prospective sources of mesenchymal stromal cells (MSCs), that can be used in cell therapy for atherosclerosis. The present study investigated whether ADSCs co‑cultured with M1 foam macrophages via treatment with oxidized low‑density lipoprotein (ox‑LDL) would lead to similar or improved anti‑inflammatory effects compared with BMSCs. ADSCs, peripheral blood monocytes, BMSCs and ox‑LDL were isolated from ten coronary heart disease (CHD) patients. After three passages, the supernatants of the ADSCs and BMSCs were collected and systematically analysed by liquid chromatography‑quadrupole time‑of‑flight‑mass spectrometry (6530; Agilent Technologies, Inc., Santa Clara, CA, USA). Cis‑9, trans‑11 was deemed to be responsible for the potential differences in the metabolic characteristics of ADSCs and BMSCs. These peripheral blood monocytes were characterized using flow cytometry. Following peripheral blood monocytes differentiation into M1 macrophages, the formation of M1 foam macrophages was achieved through treatment with ox‑LDL. Overall, 2x106 ADSCs, BMSCs or BMSCs+cis‑9, trans‑11 were co‑cultured with M1 foam macrophages. Anti‑inflammatory capability, phagocytic activity, anti‑apoptotic capability and cell viability assays were compared among these groups. It was demonstrated that the accumulation of lipid droplets decreased following ADSCs, BMSCs or BMSCs+cis‑9, trans‑11 treatment in M1 macrophages derived from foam cells. Consistently, ADSCs exhibited great advantageous anti‑inflammatory capabilities, phagocytic activity, anti‑apoptotic capability activity and cell viability over BMSCs or BMSCs+cis‑9, trans‑11. Additionally, BMSCs+cis‑9, trans‑11 also demonstrated marked improvement in anti‑inflammatory capability, phagocytic activity, anti‑apoptotic capability activity and cell viability in comparison with BMSCs. The present results indicated that ADSCs would be more appropriate for transplantation to treat atherosclerosis than BMSCs alone or BMSCs+cis‑9, trans‑11. This may be an important mechanism to regulate macrophage immune function.

Microbial Production of Conjugated Linoleic Acid and Conjugated Linolenic Acid Relies on a Multienzymatic System

Conjugated linoleic acids (CLAs) and conjugated linolenic acids (CLNAs) have gained significant attention due to their anticarcinogenic and lipid/energy metabolism-modulatory effects. However, their concentration in foodstuffs is insufficient for any therapeutic application to be implemented. From a biotechnological standpoint, microbial production of these conjugated fatty acids (CFAs) has been explored as an alternative, and strains of the genera Propionibacterium, Lactobacillus, and Bifidobacterium have shown promising producing capacities. Current screening research works are generally based on direct analytical determination of production capacity (e.g., trial and error), representing an important bottleneck in these studies. This review aims to summarize the available information regarding identified genes and proteins involved in CLA/CLNA production by these groups of bacteria and, consequently, the possible enzymatic reactions behind such metabolic processes. Linoleate isomerase (LAI) was the first enzyme to be described to be involved in the microbiological transformation of linoleic acids (LAs) and linolenic acids (LNAs) into CFA isomers. Thus, the availability of lai gene sequences has allowed the development of genetic screening tools. Nevertheless, several studies have reported that LAIs have significant homology with myosin-cross-reactive antigen (MCRA) proteins, which are involved in the synthesis of hydroxy fatty acids, as shown by hydratase activity. Furthermore, it has been suggested that CLA and/or CLNA production results from a stress response performed by the activation of more than one gene in a multiple-step reaction. Studies on CFA biochemical pathways are essential to understand and characterize the metabolic mechanism behind this process, unraveling all the gene products that may be involved. As some of these bacteria have shown modulation of lipid metabolism in vivo, further research to be focused on this topic may help us to understand the role of the gut microbiota in human health.

Uncommon Fatty Acids and Cardiometabolic Health

Cardiovascular disease (CVD) is a major cause of mortality. The effects of several unsaturated fatty acids on cardiometabolic health, such as eicosapentaenoic acid (EPA) docosahexaenoic acid (DHA), α linolenic acid (ALA), linoleic acid (LA), and oleic acid (OA) have received much attention in past years. In addition, results from recent studies revealed that several other uncommon fatty acids (fatty acids present at a low content or else not contained in usual foods), such as furan fatty acids, n-3 docosapentaenoic acid (DPA), and conjugated fatty acids, also have favorable effects on cardiometabolic health. In the present report, we searched the literature in PubMed, Embase, and the Cochrane Library to review the research progress on anti-CVD effect of these uncommon fatty acids. DPA has a favorable effect on cardiometabolic health in a different way to other long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs), such as EPA and DHA. Furan fatty acids and conjugated linolenic acid (CLNA) may be potential bioactive fatty acids beneficial for cardiometabolic health, but evidence from intervention studies in humans is still limited, and well-designed clinical trials are required. The favorable effects of conjugated linoleic acid (CLA) on cardiometabolic health observed in animal or in vitro cannot be replicated in humans. However, most intervention studies in humans concerning CLA have only evaluated its effect on cardiometabolic risk factors but not its direct effect on risk of CVD, and randomized controlled trials (RCTs) will be required to clarify this point. However, several difficulties and limitations exist for conducting RCTs to evaluate the effect of these fatty acids on cardiometabolic health, especially the high costs for purifying the fatty acids from natural sources. This review provides a basis for better nutritional prevention and therapy of CVD.

Comparative Rice Bran Metabolomics across Diverse Cultivars and Functional Rice Gene⁻Bran Metabolite Relationships

Rice (Oryza sativa L.) processing yields ~60 million metric tons of bran annually. Rice genes producing bran metabolites of nutritional and human health importance were assessed across 17 diverse cultivars from seven countries using non-targeted metabolomics, and resulted in 378–430 metabolites. Gambiaka cultivar had the highest number and Njavara had the lowest number of metabolites. The 71 rice bran compounds of significant variation by cultivar included 21 amino acids, seven carbohydrates, two metabolites from cofactors and vitamins, 33 lipids, six nucleotides, and two secondary metabolites. Tryptophan, α-ketoglutarate, γ-tocopherol/β-tocopherol, and γ-tocotrienol are examples of bran metabolites with extensive cultivar variation and genetic information. Thirty-four rice bran components that varied between cultivars linked to 535 putative biosynthetic genes using to the OryzaCyc 4.0, Plant Metabolic Network database. Rice genes responsible for bran composition with animal and human health importance is available for rice breeding programs to utilize in crop improvement.

10,12 Conjugated Linoleic Acid-Driven Weight Loss Is Protective against Atherosclerosis in Mice and Is Associated with Alternative Macrophage Enrichment in Perivascular Adipose Tissue

The dietary fatty acid 10,12 conjugated linoleic acid (10,12 CLA) promotes weight loss by increasing fat oxidation, but its effects on atherosclerosis are less clear. We recently showed that weight loss induced by 10,12 CLA in an atherosclerosis-susceptible mouse model with characteristics similar to human metabolic syndrome is accompanied by accumulation of alternatively activated macrophages within subcutaneous adipose tissue. The objective of this study was to evaluate whether 10,12 CLA-mediated weight loss was associated with an atheroprotective phenotype. Male low-density lipoprotein receptor deficient (Ldlr^−/−) mice were made obese with 12 weeks of a high-fat, high-sucrose diet feeding (HFHS: 36% fat, 36% sucrose, 0.15% added cholesterol), then either continued on the HFHS diet with or without caloric restriction (CR), or switched to a diet with 1% of the lard replaced by either 9,11 CLA or 10,12 CLA for 8 weeks. Atherosclerosis and lipid levels were quantified at sacrifice. Weight loss in mice following 10,12 CLA supplementation or CR as a weight-matched control group had improved cholesterol and triglyceride levels, yet only the 10,12 CLA-treated mice had improved en face and aortic sinus atherosclerosis. 10,12 CLA-supplemented mice had increased lesion macrophage content, with enrichment of surrounding perivascular adipose tissue (PVAT) alternative macrophages, which may contribute to the anti-atherosclerotic effect of 10,12 CLA.

Cholesterol-Lowering Nutraceuticals Affecting Vascular Function and Cardiovascular Disease Risk

PURPOSE OF REVIEW

The aim of this review is to provide an update on the effects of the dietary supplementation with cholesterol-lowering nutraceuticals and nutraceutical combinations affecting vascular function and CV risk in clinical interventional studies.

RECENT FINDINGS

Current evidence supports the mild-to-moderate cholesterol-lowering efficacy of red yeast rice, berberine, plant sterols, fibers, and some nutraceutical combinations whereas data on the individual cholesterol-lowering action of other nutraceuticals are either less striking or even inconclusive. There is also promising evidence on the vascular protective effects of some of the aforementioned nutraceuticals. However, except for red yeast rice, clinical interventional studies have not investigated their impact on CV outcomes. Evidence of both cholesterol-lowering and vascular protection is a prerogative of few single nutraceuticals and nutraceutical combinations, which may support their clinical use; however, caution on their uncontrolled adoption is necessary as they are freely available on the market and, therefore, subject to potential misuse.

Duodenal infusion of conjugated linoleic acid mixture influences milk fat synthesis and milk CLA content in dairy cows

Conjugated linoleic acids (CLA) are potent anticarcinogens secreted into the milk of ruminants. The present study was carried out to detect the post–ruminal effects of a duodenally infused commercial CLA product on milk–fat synthesis and fatty acid pattern in lactating cows. Four Holstein cows, fistulated with duodenal cannulae, were infused with 200 g of a CLA mixture daily into the duodenum over a period of 5 days (period II), while no application of CLA acted as controls in period I and III. In contrast to the marginal effect of the CLA application on milk yield, an obvious decrease of milk fat content of 40% was measured. The fat yield decreased during the infusion period to about half of the control period, whereas protein and lactose content in milk was not significantly influenced. The CLA percentage of milk fat increased sevenfold during infusion of the CLA supplement. The data demonstrate that duodenal infusion of CLA inhibits the milk fat synthesis, resulting in the decrease of milk fat content and fat yield. It can be concluded, that CLA supplements increase the CLA concentration in milk fat, which probably has to be rumen protected for oral administration.

Beneficial effect of ghee consumption over mustard oil on lipid profile: A study in North Indian adult population

Background

Ghee (G) is attributed with numerous health benefits in Ayurveda. However, due to the high saturated fat content, it has been predicted to increase the cardiovascular disease risk. Hence, the current study was performed to evaluate the effect of G consumption as compared to mustard oil (MO) on lipid profile.

Methods

Two hundred (100 males) apparently healthy adults (≥40 years) were randomly selected out of the total individuals interviewed in a house-to-house survey. They were divided into three groups based on G and MO consumption: (A) MO >1 L/month, G<0.5 kg/month; (B) MO 1–0.5 L/month, G 1.25–0.5 kg/month; and (C) MO <0.5–0.2 L/month, G>1.25 kg/month. Serum lipid parameters were compared among the groups.

Results

Group C had the significantly lowest triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), TC/HDL and LDL/HDL and highest high-density lipoprotein (HDL). A similar finding was found when analysis was done separetely for male and female.

Conclusions

A favorable lipid profile might suggest a possible beneficial effect of predominantly G consumption over MO.

Effects of flaxseed and chia seed on ruminal fermentation, nutrient digestibility, and long-chain fatty acid flow in a dual-flow continuous culture system

Flaxseed (FS) and chia seed (CS) are oilseeds rich in omega-3 fatty acids, which may change meat and milk composition when added to ruminants' diets and may have health benefits for humans. Literature on the effects of CS supplementation on ruminal metabolism is nonexistent. A dual-flow continuous culture fermenter system consisting of 6 fermenters was used to assess the effect of FS and CS supplementation in an alfalfa hay-based diet on ruminal fermentation, nutrient digestibility, microbial protein synthesis, and long-chain fatty acid flow. Diets were randomly assigned to fermenters in a replicated 3 × 3 Latin square design, with 3 consecutive periods of 10 d each, consisting of 7 d for diet adaptation and 3 d for sample collection. Each fermenter was fed a total of 72 g of DM/d divided in 6 equal portions. Treatments were 1) alfalfa hay + calcium soaps of palm oil fatty acid (MEG; 69.3 g DM/d of alfalfa hay plus 2.7 g DM/d of calcium soaps of palm oil fatty acid), 2) alfalfa hay + FS (FLAX; 68.4 g DM/d of alfalfa hay plus 3.6 g DM/d of ground FS), and 3) alfalfa hay + CS (CHIA; 68.04 g DM/d of alfalfa hay plus 3.96 g DM/d of ground CS). Dietary treatments had similar amounts of total fat, and fat supplements were ground to 2-mm diameter. Effluents from the last 3 d of incubation were composited for analyses. Data were analyzed using the MIXED procedure of SAS. Ruminal apparent and true nutrient digestibility of all nutrients did not differ ( > 0.05) among treatments. Compared with MEG, FLAX and CHIA increased the flows of C18:3 -3, C20:4 -6, and total PUFA ( < 0.01). Both CHIA and FLAX treatments had greater ruminal concentrations of C18:0, indicating that both CS and FS fatty acids were extensively biohydrogenated in the rumen. The NH-N concentration, microbial N flow, and efficiency of microbial protein synthesis were not affected ( > 0.05) by treatments. Lastly, there were no differences ( > 0.05) among diets for total VFA concentration and molar proportions of individual VFA. Results from this study indicate that FS and CS supplementation did not impair ruminal fermentation, digestibility, microbial efficiency, and ruminal N metabolism. Overall, CS appears to be as effective as FS as a fat source when added to ruminants' diets using a dual-flow continuous culture system.

Physiological Properties of Conjugated Linoleic Acid and Implications for Human Health

Conjugated linoleic acid (CLA) refers to a mixture of positional and geometric dienoic isomers of linoleic acid found naturally in animal products of ruminant sources. Recent interest in CLA research stems from the well-documented anticarcinogenic, antiatherogenic, antidiabetic, and antiobesity properties of CLA in rodents. However, there has been very little published human research on CLA. This review discusses the physiologic properties of CLA and their potential implications for human health.

The effect of commercial conjugated linoleic acid products on experimental periodontitis and diabetes mellitus in Wistar rats

OBJECTIVE

The aim of present study was to determine the effects of conjugated linoleic acid enriched milk on alveolar bone loss, hyperglycaemia, oxidative stress and apoptosis in ligature-induced periodontal disease in diabetic rat model.

METHODS

Wistar rats were divided into six experimental groups: 1; non-ligated (NL, n = 6) group, 2; ligature only (LO, n = 6) group, 3; streptozotocin only (STZ, n = 8) group, 4; STZ and ligature (STZ + L, n = 8) group, 5; ligature and conjugated linoleic acid (CLA) (L + CLA, n = 8) group, 6; STZ, ligature and CLA group (STZ + L + CLA, n = 8) group. Diabetes mellitus was induced by 60 mg/kg streptozotocin. Rats were fed with CLA enriched milk for four weeks. Silk ligatures were placed at the gingival margin of lower first molars of mandibular quadrant. The study duration was four weeks after diabetes induction and the animals were sacrificed at the end of this period. Changes in alveolar bone levels were clinically measured and tissues were histopathologically examined. Inducible nitric oxide synthase (iNOS) and Bax protein expressions, serum interleukin-1β (IL-1β), low-density lipoprotein (LDL), high-density lipoprotein (HDL) and triglyceride levels and tartrate resistant acid phosphatase (TRAP)+ osteoclast numbers were also evaluated.

RESULTS

At the end of four weeks, alveolar bone loss was significantly higher in the STZ + LO group compared to the other groups (p < .05). CLA decreased alveolar bone loss in L + CLA and STZ + L + CLA groups. CLA significantly decreased TRAP + osteoclast numbers and increased osteoblastic activity compared to the STZ + L group (p < .05). Diabetes and CLA increased Bax protein levels (p < .05) however CLA had no effect on iNOS expression (p > .05).

CONCLUSION

Within the limits of this study, commercial CLA product administration in addition to diet significantly reduced alveolar bone loss, increased osteoblastic activity and decreased osteoclastic activity in the diabetic Wistar rats.

Detection of goat body fat adulteration in pure ghee using ATR-FTIR spectroscopy coupled with chemometric strategy

Ghee forms an important component of the diet of human beings due to its rich flavor and high nutritive value. This high priced fat is prone to adulteration with cheaper fats. ATR-FTIR spectroscopy coupled with chemometrics was applied for determining the presence of goat body fat in ghee (@1, 3, 5, 10, 15 and 20% level in the laboratory made/spiked samples). The spectra of pure (ghee and goat body fat) and spiked samples were taken in the wavenumber range of 4000-500 cm^-1. Separated clusters of pure ghee and spiked samples were obtained on applying principal component analysis at 5% level of significance in the selected wavenumber range (1786-1680, 1490-919 and 1260-1040 cm^-1). SIMCA was applied for classification of samples and pure ghee showed 100% classification efficiency. The value of R² was found to be >0.99 for calibration and validation sets using partial least square method at all the selected wavenumber range which indicate that the model was well developed. The study revealed that the spiked samples of goat body fat could be detected even at 1% level in ghee.

Lipid Peroxidation Inhibitory Effects of Hizikia Fusiformis Methanolic Extract on Fish Oil and Linoleic Acid

The lipid peroxidation inhibitory effects of Hizikia fusiformis methanolic extract (HME) on fish oil and linoleic acid were studied by means of peroxide value (PV), thiobarbituric acid-reactive substances (TBARS), conjugated diene hydroperoxides (CDH) and weight gaining assays. Heat and UV light stability were determined by DPPH assay. HME significantly (p<0.05) reduced the lipid peroxidation in a dosedependent manner. Increasing the level of HME from 0.01 to 0.1% caused a higher antioxidative effect than the one produced by butylated hydroxytoluene (BHT) (BHT reported the best effect compared to -tocopherol and butylated hydroxyanisole). HME reduced the formation of primary oxidation products as showed by the lower CDH values compared to its control counterpart. HME reduced also the addition of oxygen to form lipid peroxyl radicals that indicated a low weight gaining in HME-treated oils. Moreover, it could reduce the formation of lipid peroxide. Furthermore, it diminished the total lipid peroxidation resulting in low TBARS values. The heat and UV light study showed that H. fusiformis contained heat- and UV-light resistant antioxidants. These results indicated that the H. fusiformis antioxidants could be useful in preventing oxidative damages of food oils.

Effect of double-muscling in Belgian Blue young bulls on the intramuscular fatty acid composition with emphasis on conjugated linoleic acid and polyunsaturated fatty acids

The effect of double-muscling (DM) genotype (double-muscling, mh/mh; heterozygous, mh/+; normal, +/+) of Belgian Blue (BB) young bulls on the intramuscular fatty acid composition, in particular conjugated linoleic acid (CLA) and polyunsaturated fatty acids (PUFA) was examined in five different muscles. The relative fatty acid composition showed only minor differences between muscles within genotypes. However, the DM genotype had a large effect on both the intramuscular total fatty acid content and on the relative fatty acid composition. Across muscles, the mh/mh animals had a lower total fatty acid content compared with the +/+animals (907 v: 2656 mg/100 g muscle;P< 0·01) and a higher PUFA proportion in total fatty acids (27·5 v 11·3 g/100 g total fatty acids;P< 0001), resulting in a higher PUFA/saturated fatty acid ratio (0·55 v 0·18;P< 0·01) and a lower n-6/n-3 ratio (5·34 v. 6·17;P< 0·01). The heterozygous genotype was intermediate between the two homozygous genotypes. The relative CLA content was similar in the mh/mh and +/+ genotypes and approximated 0·4 to 0·5 g/100 g total fatty acids. From the data it is further suggested that differences in the metabolism of the n-3 and n-6 fatty acids could exist between DM genotypes.

Effect of dietary lipid on the content of conjugated linoleic acid (CLA) in beef muscle

We have examined the effect of dietary fats containing n-3 polyunsaturated fatty acids on the conjugated linoleic acid (CLA) content of beef m. longissimus lumborum. Four groups of eight Charolais steers were given, for 120 days, grass silage plus a barley/sugar-beet feed concentrate containing one of four fat supplements: Megalac (saturated), linseed (high 18: 3),fish oil (high 20: 5 n-3, eicosapentenoic acid and 22: 6 n-3, docosahexaenoic acid) or linseed plus fish oil. The concentrates supplied 400 g/kg dry-matter (DM) intake and were designed to supply 45 g/kg of the total dietary fat calculated to be 60 g/kg of DM and to contain similar amounts of linoleic acid. Muscle from steers given the Megalac supplement contained 11·3 mg CLA per 100 g muscle and this was increased two- to three-fold in animals given the more unsaturated fat supplements. The increased deposition of CLA was similar for both linseed and fish oil supplements although the concentrations of total n-3 polyunsaturated fatty acids in the fish oil diet were much less than in the linseed diet. This suggests potent inhibition of conversion of CLA to trans vaccenic acid by fish oil fatty acids or their rumen metabolites.

Effects of conjugated linoleic acid on the performance of laying hens, lipid composition of egg yolk, egg flavor, and serum components

OBJECTIVE

This experiment investigated the effects of dietary supplementation with conjugated linoleic acid (CLA) on the serum components, laying hen productivity, lipid composition of egg yolk, egg flavor and egg quality.

METHODS

Healthy 28-week-old Hy-Line white laying hens (n = 480) were divided randomly into 4 groups, 6 replicates/group, 20 birds/replicate. The 30-day experimental diets included 0% (control), 0.4%, 0.8%, and 1.6% CLA. Some serum indices of the birds, and egg production, quality, fatty acid composition, egg quality were measured.

RESULTS

The dietary supplementation with 0.4%, 0.8%, and 1.6% CLA did not significantly affect the laying rate and feed intake, as well as calcium ion and phosphorus ion concentration in serum (p>0.05). However, the CLA had significantly increased the strength of eggshell, decreased the odor, flavor, and taste of egg yolk, deepened the color of egg yolk, increased saturated fatty acids and polyunsaturated fatty acids, and reduced the monounsaturated fatty acids (p<0.05). On the other hand, the dietary supplementation with 1.6% CLA had significant effects on feed/gain, and improved serum hormones. Dietary supplementation with 0.4% and 0.8% CLA can significantly enhance the activity of alkaline phosphates.

CONCLUSION

CLA has no effect on production performance, but does enhance the lipid content of the egg yolk and the strength of the eggshell.

Effects of dietary conjugated linoleic acid on cytotoxicity of peripheral blood lymphocytes in piglets

The aim of this study was to investigate the effects of dietary conjugated linoleic acid (CLA) on the cytotoxicity of peripheral blood lymphocytes in piglets. A total of forty 21-d-old Duroc × Large White × Landrace weaned piglets were randomly allocated into two treatment groups and fed with control diet or 2% CLA diet for 6 weeks. Dietary CLA significantly increased the number of peripheral blood CD8+ T lymphocytes (P < 0.05). Compared with the control group, cytotoxicity, perforin, and granzyme B mRNA expression of peripheral blood lymphocytes in piglets from the CLA-supplementation group increased by 29.98% (P < 0.01), 32.87% (P < 0.01), and 43.36% (P < 0.05), respectively. The piglets on the CLA diet had higher mRNA expression of Lck and Fyn in peripheral blood lymphocytes (P < 0.05). The content of C16:0 significantly increased in piglets from the dietary CLA-supplementation group (P < 0.05), whereas the content of C18:1 significantly decreased (P < 0.05). The CLA content of peripheral blood lymphocytes in piglets in the CLA diet group ranged up to 0.24% (P < 0.01). These results suggest that dietary CLA enhanced cytotoxicity of peripheral blood lymphocytes perhaps through changing its fatty acid composition.

Atheroprotective effects of conjugated linoleic acid

Atherosclerosis, the underlying cause of heart attack and strokes, is a progressive dyslipidaemic and inflammatory disease where monocyte-derived macrophage cells play a pivotal role. Although most of the mechanisms that contribute to the progression of atherosclerosis have been identified, there is limited information on those governing regression. Conjugated linoleic acid (CLA) is a generic term denoting a group of naturally occurring isomers of linoleic acid (18:2, n6) that differ in the position or geometry (i.e. cis or trans) of their double bonds. The most predominant isomers in ruminant fats are cis-9, trans-11 CLA (c9,t11-CLA), which accounts for more than 80% of CLA isomers in dairy products and trans-10, cis-12 CLA (t10,c12-CLA). Dietary administration of a blend of the two most abundant isomers of CLA has been shown to inhibit the progression and induce the regression of pre-established atherosclerosis. Studies investigating the mechanisms involved in CLA-induced atheroprotective effects are continually emerging. The purpose of this review is to discuss comprehensively the effects of CLA on monocyte/macrophage function in atherosclerosis and to identify possible mechanisms through which CLA mediates its atheroprotective effects.

Effects of dietary conjugated linoleic acids on cellular immune response of piglets after cyclosporin A injection

The present study investigated the effects of dietary conjugated linoleic acid (CLA) on the cellular immune response of piglets after cyclosporin A (CsA) treatment. The experimental study had a 2×2 factorial design, and the main factors consisted of diets (0% or 2% CLA) and immunosuppression treatments (CsA or saline injection). CsA injection significantly increased feed : gain (F : G) of piglets (P<0.05); however, dietary CLA significantly decreased F : G of piglets (P<0.05). Dietary CLA partly ameliorated the deterioration of the feed conversion rate caused by CsA treatment (P<0.01). CsA treatment significantly decreased the percentages of CD4+ and CD8+ T lymphocytes in the thymus (P<0.01). Dietary CLA increased the percentages of CD4+ CD8+ double-positive and CD8+ single-positive T lymphocytes in the thymus (P<0.05), and had the trend to inhibit the decrease of CD4+ T lymphocytes in the thymus after CsA injection (P=0.07). CsA treatment significantly depleted the peripheral blood CD3+, CD4+ and CD8+ T lymphocytes (P<0.01). Dietary CLA significantly increased the number of peripheral blood CD8+ T lymphocytes and interleukin-2 (IL-2) production (P<0.05), and inhibited the decreases of peripheral blood CD3+, CD4+ and CD8+ T lymphocytes counts (P<0.01) as well as IL-2 production (P<0.05) after CsA treatment. Dietary CLA partly rescued the decrease of lymphocyte proliferation after CsA injection (P<0.05). In summary, dietary CLA effectively ameliorated CsA-induced cellular immunosuppression in piglets.

Anti-obesity and anti-diabetic effects of a standardized potato extract in ob/ob mice

The potato (Solanum tuberosum) has been cultivated globally for food for millenia. Potato contains proteinase inhibitor II, which catalyzes the release of cholecystokinin (CCK), leading to delayed gastric emptying in humans. The present study investigated the anti-obesity effects of Slendesta™ Potato Extract (SLD), a standardized potato extract containing 5% proteinase inhibitor II, in the ob/ob obese mice. Three doses of SLD (50, 150 or 300 mg/kg) were orally administered to ob/ob mice once a day for 28 days, whereas control mice were administered distilled water. Four weeks after SLD treatment, the changes in body weight, food consumption, epididymal fat weight, serum chemistry, insulin, leptin and adiponectin contents, and fat histopathology were determined and compared with ob/ob mice treated with 750 mg/kg conjugate linoleic acid. As a result of SLD treatment in the obese mice, body weight, food consumption, epididymal fat, serum biochemistry, histomorphological changes of fat and pancreas were significantly and dose-dependently decreased compared with ob/ob control mice. These obesity and type 2 diabetes associated alterations were significantly inhibited after SLD treatment for 28 days. Thus, the present results indicate that SLD has potential as an alternative therapeutic agent for obesity.