Potent inhibitory effect of trans9, trans11 isomer of conjugated linoleic acid on the growth of human colon cancer cells

The omega-3 postbiotic trans-10-cis-15-octadecadienoic acid attenuates contact hypersensitivity in mice through downregulation of vascular endothelial growth factor A

Intestinal bacteria metabolize dietary substances to produce bioactive postbiotics, among which some are recognized for their role in promoting host health. We here explored the postbiotic potential of two omega-3 α-linolenic acid-derived metabolites: trans-10-cis-15-octadecadienoic acid (t10,c15-18:2) and cis-9-cis-15-octadecadienoic acid (c9,c15-18:2). Dietary intake of lipids rich in omega-3 α-linolenic acid elevated levels of t10,c15-18:2 and c9,c15-18:2 in the serum and feces of mice, an effect dependent on the presence of intestinal bacteria. Notably, t10,c15-18:2 mitigated skin inflammation in mice that became hypersensitive after exposure to 2,4-dinitrofluorobenzene, an experimental model for allergic contact dermatitis. In particular, t10,c15-18:2-but not c9,c15-18:2-attenuated ear swelling and edema, characteristic symptoms of contact hypersensitivity. The anti-inflammatory effects of t10,c15-18:2 were due to its ability to suppress the release of vascular endothelial growth factor A from keratinocytes, thereby mitigating the enhanced vascular permeability induced by hapten stimulation. Our study identified retinoid X receptor as a functional receptor that mediates the downregulation of skin inflammation upon treatment with t10,c15-18:2. Our results suggest that t10,c15-18:2 holds promise as an omega-3 fatty acid-derived postbiotic with potential therapeutic implications for alleviating the skin edema seen in allergic contact dermatitis-induced inflammation.

Levels of lipid-derived gut microbial metabolites differ among plant matrices in an in vitro model of colon fermentation

This study explored differences in microbial lipid metabolites among sunflower seeds, soybeans, and walnuts. The matrices were subjected to in vitro digestion and colonic fermentation. Defatted digested materials and fiber/phenolics extracted therefrom were added to sunflower oil (SO) and also fermented. Targeted and untargeted lipidomics were employed to monitor and tentatively identify linoleic acid (LA) metabolites. Walnut fermentation produced the highest free fatty acids (FFAs), LA, and conjugated LAs (CLAs). Defatted digested walnuts added to SO boosted FFAs and CLAs production; the addition of fibre boosted CLAs, whereas the addition of phenolics only increased 9e,11z-CLA and 10e,12z-CLA. Several di-/tri-hydroxy-C18-FAs, reported as microbial LA metabolites for the first time, were annotated. Permutational multivariate analysis of variance indicated significant impacts of food matrix presence and type on lipidomics and C18-FAs. Our findings highlight how the food matrices affect CLA production from dietary lipids, emphasizing the role of food context in microbial lipid metabolism.

Unveiling the anticancer potentiality of single cell oils produced by marine oleaginous Paradendryphiella sp. under optimized economic growth conditions

Bioprospecting about new marine oleaginous fungi that produce advantageous bioproducts in a green sustainable process is the key of blue bioeconomy. Herein, the marine Paradendryphiella sp. was utilized for single cell oils (SCOs) production economically, via central composite design, the lipid content enhanced 2.2-fold by 5.5 g/L lipid yeild on seawater-based media supplemented with molasses concentration 50 g/L, yeast extract, 2.25 g/L at initial pH value (5.3) and 8 days of static incubation. Subsequently, the fatty acid methyl esters profiles of SCOs produced on optimized media under different abiotic conditions were determined; signifying qualitative and quantitative variations. Interestingly, the psychrophilic-prolonged incubation increased the unsaturation level of fatty acids to 59.34%, while ω-6 and ω-3 contents representing 23.53% and 0.67% respectively. Remarkably, it exhibited the highest EC100 dose by 677.03 µg/mL on normal human lung fibroblast Wi-38 cells. Meanwhile, it showed the highest inhibiting proliferation potential on cancer cell lines of A549, MDA-MB 231 and HepG-2 cells by 372.37, 417.48 and 365.00 µg/mL, respectively. Besides, it elevated the oxidative stress, the expression of key apoptotic genes and suppressed the expression of key oncogenes (NF-κB, BCL2 and cyclin D); implying its promising efficacy in cancer treatment as adjuvant drug. This study denoted the lipogenesis capacity of Paradendryphiella sp. under acidic/alkaline and psychrophilic/mesophilic conditions. Hereby attaining efficient and economic process under seasonal variation with different Egyptian marine sources to fill the gap of freshwater crisis and simultaneously preserve energy.

Consuming almonds with chocolate or lettuce influences oral processing behaviour, bolus properties and consequently predicted lipid release from almonds

Lipids in almonds are naturally encapsulated by cell walls which may reduce the actual metabolizable energy content of almonds. Oral processing increases the accessibility of lipids to digestive enzymes by grinding the almond matrix. This study aimed to investigate the effect of adding accompanying foods (chocolate and iceberg lettuce) to almonds on oral processing behaviour, bolus properties and predicted lipid release. Natural chewing times of four almond model foods including one almond (1.3 g), four almonds (4.6 g), one almond with chocolate (4.3 g) and one almond with iceberg lettuce (4.3 g) were collected from n = 59 participants in duplicate. Expectorated boli at the moment of swallowing were characterized for number and mean area of almond bolus particles. Predicted lipid bioaccessibility was estimated using a previously validated model. At similar bite size (4.3-4.6 g), the addition of chocolate and iceberg lettuce to almonds significantly decreased (p < 0.05) chewing time and significantly increased (p < 0.05) eating rate compared to consumption of almonds alone. Almond bolus particle sizes were similar for almonds consumed alone (one and four almonds) and with chocolate, while consuming almonds with lettuce generated significantly fewer and larger almond bolus particles (p < 0.05). Predicted lipid bioaccessibility of almonds consumed with iceberg lettuce was significantly lower (p < 0.05) than for almonds consumed alone (one and four almonds) and almonds consumed with chocolate. Eating rate correlated significantly and positively with the mean area of bolus particles and significantly and negatively with predicted lipid release. In conclusion, combining almonds with other foods such as chocolate and lettuce influences oral processing behaviour and bolus properties and consequently predicted lipid bioaccessibility of almonds, highlighting the impact of food matrix and consumption context on these aspects.

Zanthoxylum bungeanum seed oil inhibits tumorigenesis of human melanoma A375 by regulating CDC25A/CyclinB1/CDK1 signaling pathways in vitro and in vivo

Background:Zanthoxylum bungeanum seed oil (ZBSO) is extracted from the seeds of the traditional Chinese medicine Z. bungeanum Maxim, which has been shown to have anti-melanoma effects. However, the specific mechanisms are not illustrated adequately.

Aims: To further investigate the mechanism by which ZBSO inhibits melanoma and to provide scientific evidence to support ZBSO as a potential melanoma therapeutic candidate.

Methods: CCK-8 assays were used to detect the function of ZBSO on A375 cells. Based on transcriptomics analyses, Western blot analysis was applied to determine whether an association existed in ZBSO with the CDC25A/CyclinB1/CDK1 signaling pathway. In addition, RT-qPCR and immunohistochemistry analysis validated that ZBSO has the anti-melanoma effect in a nude mouse xenograft model of human melanoma. Then, 16S rRNA sequencing was used to detect the regulation of gut microbes.

Results: Cellular assays revealed that ZBSO could inhibit A375 cell viability by regulating the cell cycle pathway. Further studies presented that ZBSO could constrain CDC25A/CyclinB1/CDK1 signaling pathway in vitro and in vivo models of melanoma. ZBSO did not produce toxicity in mice, and significantly reduced tumor volume in xenotransplants of A375 cells. Genome analysis indicated that ZBSO successfully altered specific gut microbes.

Conclusion: ZBSO inhibited the growth of A375 cells by regulating CDC25A/cyclinB1/CDK1 signaling pathway both in vitro and in vivo, suggesting that ZBSO may be a novel potential therapeutic agent.

Insights into gut microbiota metabolism of dietary lipids: the case of linoleic acid

It has been recognized that, next to dietary fibre and proteins, gut microbiota can metabolize lipids producing bioactive metabolites. However, the metabolism of dietary lipids by human gut microbiota has been poorly explored so far. This study aimed to examine the change in lipids, particularly linoleic acid (LA), induced by the chemical form of lipids and the presence of the plant matrix. Short-chain fatty acid (SCFA) production was monitored to get an insight into microbial activity. Free LA, glyceryl trilinoleate and soybean oil as well as digested intact (DS) and broken (BS) soybean cells were subjected to in vitro fermentation using human faecal inoculums. Confocal microscopy was used to visualize the soybean cell integrity. Three LA metabolites, including two conjugated fatty acids (CLAs, 9z,11e and 9e,11e) and 12hydroxy, 9z C18:1, were identified and monitored. Free LA addition improved the LA metabolite production but reduced SCFA concentrations compared to trilinoleate and soybean oil. Breaking cell integrity had impacts on CLA, hydroxy C18:1 and SCFA production and free fatty acid release within the first 24 h of fermentation, but this effect vanished with time. In contrast, soybean oil only increased free LA release and hydroxy C18:1 production. The content of several FAs decreased during fermentation suggesting a substantial conversion in microbial metabolites. Besides, LA metabolites were also identified in the fermentation pellets suggesting the incorporation of microbial FA metabolites into bacterial cells. This study expands our understanding of microbial metabolism of dietary lipids with a special emphasis on the role of food- and diet-related factors.

Bioactive compounds: Application of albumin nanocarriers as delivery systems

Enriched products with bioactive compounds (BCs) show the capacity to produce a wide range of possible health effects. Most BCs are essentially hydrophobic and sensitive to environmental factors; so, encapsulation becomes a strategy to solve these problems. Many globular proteins have the intrinsic ability to bind, protect, encapsulate, and introduce BCs into nutraceutical or pharmaceutical matrices. Among them, albumins as human serum albumin (HSA), bovine serum albumin (BSA), ovalbumin (OVA) and α-lactalbumin (ALA) are widely abundant, available, and applied in many industrial sectors, becoming promissory materials to encapsulate BCs. Therefore, this review focuses on researches about the main groups of natural origin BCs (namely phenolic compounds, lipids, vitamins, and carotenoids), the different types of nanostructures based on albumins to encapsulate them and the main fields of application for BCs-loaded albumin systems. In this context, phenolic compounds (catechins, quercetin, and chrysin) are the most extensively BCs studied and encapsulated in albumin-based nanocarriers. Other extensively studied subgroups are stilbenes and curcuminoids. Regarding lipids and vitamins; terpenes, carotenoids (β-carotene), and xanthophylls (astaxanthin) are the most considered. The main application areas of BCs are related to their antitumor, anti-inflammatory, and antioxidant properties. Finally, BSA is the most used albumin to produced BCs-loaded nanocarriers.

Probiotic Properties of Lactic Acid Bacteria with High Conjugated Linoleic Acid Converting Activity Isolated from Jeot-Gal, High-Salt Fermented Seafood

Conjugated linoleic acid (CLA) isomers are potent health-promoting fatty acids. This study evaluated the probiotic properties of 10 strains of high CLA-producing lactic acid bacteria (LAB) isolated from Jeot-gal, a high-salt, fermented seafood. Two isolates, Lactiplantibacillus plantarum JBCC105683 and Lactiplantibacillus pentosus JBCC105676, produced the largest amounts of CLA (748.8 and 726.9 μg/mL, respectively). Five isolates, L. plantarum JBCC105675, L. pentosus JBCC105676, L. pentosus JBCC105674, L. plantarum JBCC105683, and Lactiplantibacillus paraplantarum JBCC105655 synthesized more cis-9, trans-11-CLA than trans-10, cis-12-CLA (approximately 80:20 ratio). All the strains survived severe artificial acidic environments and showed antimicrobial activity and strong adhesion capability to Caco-2 cells as compared to the commercial strain Lactocaseibacillus rhamnosus GG. Among them, Pediococcus acidilactici JBCC105117, L. paraplantarum JBCC105655, and L. plantarum JBCC105683 strongly stimulated the immunological regulatory gene PMK-1 and the host defense antimicrobial peptide gene clec-60 in Caenorhabditis elegans. Moreover, three strains showed a significant induction of tumor necrosis factor-α, interleukin (IL)-1β, IL-6, IL-12, and IL-10 production in RAW 264.7 macrophages, indicating that they were promising candidates for probiotics with high CLA-converting activity. Our results indicate that the newly isolated CLA-producing LAB might be useful as a functional probiotic with beneficial health effects that modulate the immune system.

A review on engineered magnetic nanoparticles in Non-Small-Cell lung carcinoma targeted therapy

There are growing appeals forthe design of efficacious treatment options for non-small-cell lung carcinoma (NSCLC) as it accrues to ~ 85% cases of lung cancer. Although platinum-based doublet chemotherapy has been the main therapeutic intervention in NSCLC management, this leads to myriad of problems including intolerability to the doublet regimens and detrimental side effects due to high doses. A new approach is therefore needed and warrants the design of targeted drug delivery systems that can halt tumor proliferation and metastasis by targeting key molecules, while exhibiting minimal side effects and toxicity. This review aims to explore the rational design of magnetic nanoparticles for the development of tumor-targeting systems for NSCLC. In the review, we explore the anticancer merits of conjugated linoleic acid (CLA) and provide a concise incursion into its application for the invention of functionalized magnetic nanoparticles in the targeted treatment of NSCLC. Recent nanoparticle-based targeted chemotherapies for targeting angiogenesis biomarkers in NSCLC will also be reviewed to further highlight versatility of magnetic nanoparticles. These developments through molecular tuning at the nanoscale and supported by comprehensive pre-clinical studies could lead to the establishment of precise nanosystems for tumor-homing cancer therapy.

In vitro gastrointestinal digestion and cytotoxic effect of ovalbumin-conjugated linoleic acid nanocomplexes

The aim of this work was to examine the behavior of conjugated linoleic acid (CLA) delivery systems based on ovalbumin (OVA) and their derived nanoparticles (OVA_n1 and OVA_n2), under static in vitro gastrointestinal digestion model. In addition, potential cytotoxic effect of these inclusion complexes on a human colon cancer cell line (HT-29) was evaluated. OVA was resistant to gastric and intestinal digestion, while OVA nanoparticles were very susceptible to digestive enzymes hydrolysis. Particle size distribution (PDS) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) for OVA evidenced the presence of a protein fragment of similar size after simulated digestive process. Conversely, for nanoparticles, partial and total hydrolysis in gastric and intestinal phases, respectively, was evidenced. After in vitro gastrointestinal digestion, released CLA (R_CLA) was assayed. In case of OVA, as CLA carrier, R_CLA was 37%, while for OVA nanoparticles, lower R_CLA values (~10-20%) were obtained. From cytotoxic assays, it was observed that CLA molecule was responsible for cell death, whereas OVA or their derived nanoparticles were not cytotoxic on HT-29 cells. On the other hand, flow cytometry analysis revealed that main death mechanism for CLA, and their inclusion complexes was apoptosis. OVA-CLA and OVA_n1-CLA inclusion complexes displayed the highest potential cytotoxic activity and apoptotic index. Information derived from this work could be relevant for the design of CLA delivery systems as promising nanosupplements for production of new functional and excipient foods for both prevention and control of colon cancer.

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.

Maternal Linoleic Acid Overconsumption Alters Offspring Gut and Adipose Tissue Homeostasis in Young but Not Older Adult Rats

Maternal n-6 polyunsaturated fatty acids (PUFA) consumption during gestation and lactation can predispose offspring to the development of metabolic diseases such as obesity later in life. However, the mechanisms underlying the potential programming effect of n-6 PUFA upon offspring physiology are not yet all established. Herein, we investigated the effects of maternal and weaning linoleic acid (LA)-rich diet interactions on gut intestinal and adipose tissue physiology in young (3-month-old) and older (6-month-old) adult offspring. Pregnant rats were fed a control diet (2% LA) or an LA-rich diet (12% LA) during gestation and lactation. At weaning, offspring were either maintained on the maternal diet or fed the other diet for 3 or 6 months. At 3 months of age, the maternal LA-diet favored low-grade inflammation and greater adiposity, while at 6 months of age, offspring intestinal barrier function, adipose tissue physiology and hepatic conjugated linoleic acids were strongly influenced by the weaning diet. The maternal LA-diet impacted offspring cecal microbiota diversity and composition at 3 months of age, but had only few remnant effects upon cecal microbiota composition at 6 months of age. Our study suggests that perinatal exposure to high LA levels induces a differential metabolic response to weaning diet exposure in adult life. This programming effect of a maternal LA-diet may be related to the alteration of offspring gut microbiota.

The dietary c9,t11-conjugated linoleic acid enriched from butter reduces breast cancer progression in vivo

The c9,t11-conjugated linoleic acid (CLA), which is the minor polyunsaturated fatty acid (PUFA) naturally present in butter, has gained attention due to its important preventive effect against breast cancer in vitro. In this paper, the enrichment of c9,t11-CLA from butter was optimized and the preventive effect of dietary c9,t11-CLA against breast cancer in vivo was investigated. Results showed that the concentration of c9,t11-CLA increased more than 10 times via a one-step urea complexation. Furthermore, the dietary c9,t11-CLA showed obvious preventive effect against breast cancer in decreasing the tumor weight and volume, and reducing the tumor incidence up to 50%. In addition, the expression of progesterone receptor and Ki-67 decreased significantly with the treatment of c9,t11-CLA. In conclusion, the dietary c9,t11-CLA enriched from butter showed a preventive effect against breast cancer in vivo via the inhibition of the hormonal receptor and cell proliferation. PRACTICAL APPLICATIONS: This paper provided new insight into the preparation of specific c9,t11-CLA isomer. It can be enriched from butter in large-scale with low-cost by urea complexation. Meanwhile, the enriched dietary c9,t11-CLA can be further processed into cancer prevention functional foods.

Lipase Catalyzed Acidolysis for Efficient Synthesis of Phospholipids Enriched with Isomerically Pure cis-9,trans-11 and trans-10,cis-12 Conjugated Linoleic Acid

The production of phospholipid (PL) conjugates with biologically active compounds is nowadays an extensively employed approach. This type of phospholipids conjugates could improve bioavailability of many poorly absorbed active compounds such as isomers of conjugated linoleic acid (CLA), which exhibit versatile biological effects. The studies were carried out to elaborate an efficient enzymatic method for the synthesis of phospholipids with pure (>90%) cis-9,trans-11 and trans-10,cis-12 CLA isomers. For this purpose, three commercially available immobilized lipases were examined in respect to specificity towards CLA isomers in acidolysis of egg-yolk phosphatidylcholine (PC). Different incorporation rates were observed for the individual CLA isomers. Under optimal conditions: PC/CLA molar ratio 1:6; Rhizomucor miehei lipase loading 24% wt. based on substrates; heptane; DMF, 5% (v/v); water activity (aw), 0.11; 45 °C; magnetic stirring, 300 rpm; 48 h., effective incorporation (EINC) of CLA isomers into PC reached ca. 50%. The EINC of CLA isomers was elevated for 25–30% only by adding a water mimic (DMF) and reducing aw to 0.11 comparing to the reaction system performed at aw = 0.23. The developed method of phosphatidylcholine acidolysis is the first described in the literature dealing with isometrically pure CLA and allow to obtain very high effective incorporation.

Trans10,cis12 conjugated linoleic acid inhibits proliferation and migration of ovarian cancer cells by inducing ER stress, autophagy, and modulation of Src

The goal of this study was to investigate the anti-cancer effects of Trans10,cis12 conjugated linoleic acid (t10,c12 CLA). MTT assays and QCM™ chemotaxis 96-wells were used to test the effect of t10,c12 CLA on the proliferation and migration and invasion of cancer cells. qPCR and Western Blotting were used to determine the expression of specific factors. RNA sequencing was conducted using the Illumina platform and apoptosis was measured using a flow cytometry assay. t10,c12 CLA (IC50, 7 μM) inhibited proliferation of ovarian cancer cell lines SKOV-3 and A2780. c9,t11 CLA did not attenuate the proliferation of these cells. Transcription of 165 genes was significantly repressed and 28 genes were elevated. Genes related to ER stress, ATF4, CHOP, and GADD34 were overexpressed whereas EDEM2 and Hsp90, genes required for proteasomal degradation of misfolded proteins, were downregulated upon treatment. While apoptosis was not detected, t10,c12 CLA treatment led to 9-fold increase in autophagolysosomes and higher levels of LC3-II. G1 cell cycle arrest in treated cells was correlated with phosphorylation of GSK3β and loss of β-catenin. microRNA miR184 and miR215 were upregulated. miR184 likely contributed to G1 arrest by downregulating E2F1. miR215 upregulation was correlated with increased expression of p27/Kip-1. t10,c12 CLA-mediated inhibition of invasion and migration correlated with decreased expression of PTP1b and decreased Src activation by inhibiting phosphorylation at Tyr416. Due to its ability to inhibit proliferation and migration, t10,c12 CLA should be considered for treatment of ovarian cancer.

Dietary fatty acids modulation of human colon cancer cells: mechanisms and future perspectives

Colorectal cancer (CRC) is one of the most common malignancies worldwide and its pathogenesis is proven to be related with dietary patterns, namely dietary fatty acid (FA) intake. We reviewed the evidences regarding the effect of different dietary FAs on human CRC cell lines proliferation and apoptosis. Altogether, the results obtained from in vitro studies show that monounsaturated FAs lack evidence regarding both proliferation and apoptosis, whereas there is a consensus about the anti-proliferative and pro-apoptotic effects, involving different intracellular targets, of n-3 polyunsaturated FAs, while n-6 series show a similar effect or no effects. The response to these dietary components depends on the cell type as well as the amount and duration of exposure. These results highlight the importance of identifying molecular targets for dietary components aiming to interfere with one of the main risk factors related with CRC incidence and prevalence.

Characterization of the liver X receptor-dependent regulatory mechanism of goat stearoyl-coenzyme A desaturase 1 gene by linoleic acid

Stearoyl-coenzyme A desaturase 1 (SCD1) is a key enzyme in the biosynthesis of palmitoleic and oleic acid. Although the transcriptional regulatory mechanism of SCD1 via polyunsaturated fatty acids (PUFA) has been extensively explored in nonruminants, the existence of such mechanism in ruminant mammary gland remains unknown. In this study, we used goat genomic DNA to clone and sequence a 1,713-bp fragment of the SCD1 5' flanking region. Deletion assays revealed a core region of the promoter located between -415 and -109 bp upstream of the transcription start site, and contained the highly conserved PUFA response region. An intact PUFA response region was required for the basal transcriptional activity of SCD1. Linoleic acid reduced endogenous expression of SCD1 and sterol regulatory element binding factor-1 (SREBF1) in goat mammary epithelial cells. Further analysis indicated that both the sterol response element (SRE) and the nuclear factor Y (NF-Y) binding site in the SCD1 promoter were responsible for the inhibition effect by linoleic acid, whereas the effect was abrogated once NF-Y was deleted. In addition, SRE and NF-Y were partly responsible for the transcriptional activation induced via the liver X receptor agonist T 4506585 (Sigma-Aldrich, St. Louis, MO). When goat mammary epithelial cells were cultured with linoleic acid, addition of T 4506585 markedly increased SCD1 transcription in controls, but had no effect on cells with a deleted SRE promoter. These results demonstrated that linoleic acid can regulate SCD1 expression at the transcriptional level through SRE and NF-Y in a liver X receptor-dependent fashion in the goat mammary gland.

Bifidobacterium breve with α-linolenic acid alters the composition, distribution and transcription factor activity associated with metabolism and absorption of fat

This study focused on the mechanisms that fatty acid conjugating strains - Bifidobacterium breve NCIMB 702258 and Bifidobacterium breve DPC 6330 - influence lipid metabolism when ingested with α-linolenic acid (ALA) enriched diet. Four groups of BALB/c mice received ALA enriched diet (3% (w/w)) either alone or in combination with B. breve NCIMB 702258 or B. breve DPC 6330 (10⁹ CFU/day) or unsupplemented control diet for six weeks. The overall n-3 PUFA score was increased in all groups receiving the ALA enriched diet. Hepatic peroxisomal beta oxidation increased following supplementation of the ALA enriched diet with B. breve (P < 0.05) and so the ability of the strains to produce c9t11 conjugated linoleic acid (CLA) was identified in adipose tissue. Furthermore, a strain specific effect of B. breve NCIMB 702258 was found on the endocannabinoid system (ECS). Liver triglycerides (TAG) were reduced following ALA supplementation, compared with unsupplemented controls (P < 0.01) while intervention with B. breve further reduced liver TAG (P < 0.01), compared with the ALA enriched control. These data indicate that the interactions of the gut microbiota with fatty acid metabolism directly affect host health by modulating n-3 PUFA score and the ECS.

Bacterial production of conjugated linoleic and linolenic Acid in foods: a technological challenge

Conjugated linoleic acid (CLA) and conjugated linolenic acid (CLNA) isomers are present in foods derived from ruminants as a result of the respective linoleic acid (LA) and α-linolenic acid (LNA) metabolism by ruminal microorganisms and in animals' tissues. CLA and CLNA have isomer-specific, health-promoting properties, including anticarcinogenic, antiatherogenic, anti-inflammatory, and antidiabetic activity, as well as the ability to reduce body fat. Besides ruminal microorganisms, such as Butyrivibrio fibrisolvens, many food-grade bacteria, such as bifidobacteria, lactic acid bacteria (LAB), and propionibacteria, are able to convert LA and LNA to CLA and CLNA, respectively. Linoleate isomerase activity, responsible for this conversion, is strain-dependent and probably related to the ability of the producer strain to tolerate the toxic effects of LA and LNA. Since natural concentrations of CLA and CLNA in ruminal food products are relatively low to exert their health benefits, food-grade bacteria with linoleate isomerase activity could be used as starter or adjunct cultures to develop functional fermented dairy and meat products with increased levels of CLA and CLNA or included in fermented products as probiotic cultures. However, results obtained so far are below expectations due to technological bottlenecks. More research is needed to assess if bacterial production kinetics can be increased and can match food processing requirements.

The impact of technical cashew nut shell liquid on thermally-induced trans isomers in edible oils

The effects of technical cashew nut shell liquid (TCNSL) on the trans isomerization of edible oils during heating are investigated. Edible oils were subjected to thermal treatment at various heating times and temperatures. Our results show that the addition of TCNSL to edible oils at the appropriate concentration during heating suppresses trans fatty acid formation and induces formation of conjugated linoleic acid (CLA) isomers. A concentration of 0.2 % TCNSL demonstrates the best ability to inhibit formation of trans-oleic acid, trans-linoleic acid, and trans-linolenic acid isomers as well as increase the formation of 9 t,11 t-CLA and 10 t,12 t-CLA isomers. Our analysis indicates that the presence of 0.2 % TCNSL in corn oil does not significantly reduce the acid value, but may significantly lower the peroxide value. TCNSL is also observed to have better function compared to Vitamin E (VE) and tertiary butylhydroquinone (TBHQ), indicating that it may be considered an effective additive in edible oils.

Anti-cancer activities of ω-6 polyunsaturated fatty acids

The ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) are two major families of PUFAs present as essential cellular components which possess diverse bioactivities. The ω-3s, mainly found in seafood, are associated with many beneficial effects on human health, while the ω-6s are more abundant in our daily diet and could be implicated in many pathological processes including cancer development. Increasing evidence suggests that the adverse effects of ω-6s may be largely attributed to arachidonic acid (AA, a downstream ω-6) and the metabolite prostaglandin E2 (PGE2) that stems from its cyclooxygenase (COX)-catalyzed lipid peroxidation. On the other hand, two of AA's upstream ω-6s, γ-linolenic acid (GLA) and dihomo-γ-linolenic acid (DGLA), are shown to possess certain anti-cancer activities, including inducing cell apoptosis and inhibiting cell proliferation. In this paper, we review the documented anti-cancer activities of ω-6 PUFAs, including the recent findings regarding the anti-cancer effects of free radical-mediated DGLA peroxidation. The possible mechanisms and applications of DGLA (and other ω-6s) in inducing anti-cancer activity are also discussed. Considering the wide availability of ω-6s in our daily diet, the study of the potential beneficial effect of ω-6 PUFAs may guide us to develop an ω-6-based diet care strategy for cancer prevention and treatment.

Effect of trans, trans CLA egg enrichment from CLA-rich soy oil on yolk fatty acid composition, viscosity and physical properties

CLA egg accumulation studies using cis, trans (c,t) isomers have been effective, but they reported adverse egg quality. trans, trans (t,t) CLA isomers have shown superior nutritional effects in rodent studies, but reports of t,t CLA-rich yolks are limited. The objectives were to determine the effect of t,t CLA-rich soy oil in feed on egg yolk viscosity, and yolk quality during refrigerated storage. Yolk fatty acids, viscosity, weight, index, moisture, pH, and vitelline membrane strength (VMS) were determined at 0, 20, and 30 storage days. CLA had minimal effect on fatty acid profiles, relative to c,t reports. CLA-rich yolk viscosity was greater than controls, and CLA yolks maintained higher viscosities during storage. Yolk weight and index were not affected by t,t CLA-rich soy oil. Yolks with the greatest CLA concentrations had the greatest VMS after 20 days of storage, and yolks containing lower CLA levels maintained greater VMS throughout 30 days of storage, relative to controls.

Phosphatidylcholine with cis-9,trans-11 and trans-10,cis-12 Conjugated Linoleic Acid Isomers: Synthesis and Cytotoxic Studies

Novel phosphatidylcholines and lysophosphatidylcholines with cis-9,trans-11 and trans-10,cis-12 conjugated linoleic acid (CLA) were synthesized in high yields (75–99 %). The in vitro cytotoxic activities of these compounds against three human cancer cell lines (HL-60, MCF-7, and HT-29) were evaluated. The results revealed that there are differences in the activity between phosphatidylcholine with cis-9,trans-11 and trans-10,cis-12 CLA acyl groups. 1,2-Di(9Z,11E)-octadecadienoyl-sn-glycero-3-phosphocholine was the most potent cytotoxic agent among all tested CLA derivatives and its IC50 (concentration of a compound that inhibits the proliferation of 50 % of the cancer cell population) was 29.4 µM against HL-60. Moreover, phosphatidylcholines with CLA acyls exhibited much lower cytotoxicity against non-cancer cells (Balb/3T3) than free CLA isomers.

Genes regulating lipid and protein metabolism are highly expressed in mammary gland of lactating dairy goats

Dairy goats serve as an important source of milk and also fulfill agricultural and economic roles in developing countries. Understanding the genetic background of goat mammary gland is important for research on the regulatory mechanisms controlling tissue function and the synthesis of milk components. We collected tissue at four different stages of goat mammary gland development and generated approximately 25 GB of data from Illumina de novo RNA sequencing. The combined reads were assembled into 51,361 unigenes, and approximately 60.07 % of the unigenes had homology to other proteins in the NCBI non-redundant protein database (NR). Functional classification through eukaryotic Ortholog Groups of Protein (KOG), gene ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed that the unigenes from goat mammary glands are involved in a wide range of biological processes and metabolic pathways, including lipid metabolism and lactose metabolism. The results of qPCR revealed that genes encoding FABP3, FASN, SCD, PLIN2, whey proteins (LALBA and BLG), and caseins (CSN1S1, CSN1S2, CSN2 and CSN3) at 100 and 310 days postpartum increased significantly compared with the non-lactating period. In addition to their role in lipid and protein synthesis, the higher expression at 310 days postpartum could contribute to mammary cell turnover during pregnancy. In conclusion, this is the first study to characterize the complete transcriptome of goat mammary glands and constitutes a comprehensive genomic resource available for further studies of ruminant lactation.

Improved fatty acid analysis of conjugated linoleic acid rich egg yolk triacylglycerols and phospholipid species

Reports from chicken conjugated linoleic acid (CLA) feeding trials are limited to yolk total fatty acid composition, which consistently described increased saturated fatty acids and decreased monounsaturated fatty acids. However, information on CLA triacylglycerol (TAG) and phospholipid (PL) species is limited. This study determined the fatty acid composition of total lipids in CLA-rich egg yolk produced with CLA-rich soy oil, relative to control yolks using gas chromatography with flame ionization detection (GC-FID), determined TAG and PL fatty acid compositions by thin-layer chromatography-GC-FID (TLC-GC-FID), identified intact PL and TAG species by TLC-matrix-assisted laser desorption/ionization mass spectrometry (TLC-MALDI-MS), and determined the composition of TAG and PL species in CLA and control yolks by direct flow infusion electrospray ionization MS (DFI ESI-MS). In total, 2 lyso-phosphatidyl choline (LPC) species, 1 sphingomyelin species, 17 phosphatidyl choline species, 19 TAG species, and 9 phosphatidyl ethanolamine species were identified. Fifty percent of CLA was found in TAG, occurring predominantly in C52:5 and C52:4 TAG species. CLA-rich yolks contained significantly more LPC than did control eggs. Comprehensive lipid profiling may provide insight on relationships between lipid composition and the functional properties of CLA-rich eggs.

The anti-proliferative and pro-apoptotic effects of the trans9, trans11 conjugated linoleic acid isomer on MCF-7 breast cancer cells are associated with LXR activation

Conjugated linoleic acids (CLA), naturally found in dairy products and ruminant meat, are positional and geometric isomers (trans: t or cis: c) of linoleic acid, and have been widely reported to possess anti-tumoral activity against breast cancer both in vitro and in vivo. CLA isomer t9,t11 was recently proposed as an agonist of the transcriptional factor LXR, which is known for inducing genes implicated in cholesterol efflux. In this study, the growth inhibitory effect of three CLA isomers (c9,t11-CLA, t9,t11-CLA and t10,c12-CLA) was investigated on MCF-7 breast cancer cells, as well as their effect on LXR target genes. Our results revealed that t9,t11-CLA was the most efficient isomer by decreasing MCF-7 proliferation, inhibiting migration, and inducing apoptosis after 24h of treatment. t9,t11-CLA treatment led to an increase in the mRNA levels of LXR target genes involved in cholesterol efflux (ABCG1 and ARL7), as well as an increase of HMG-CoA-reductase which is the rate-limiting step of cholesterol biosynthesis. Interestingly, confocal microscopy analysis showed that t9,t11-CLA treatment remarkably reduced the intracellular and membrane-associated cholesterol levels. LXR activation through t9,t11-CLA isomer could lead to cholesterol cell deprivation by stimulating its efflux, which results in the inhibition of cell proliferation and stimulation of apoptosis.

Synthesis of Phosphatidylcholine with Conjugated Linoleic Acid and Studies on Its Cytotoxic Activity

Phospholipids with conjugated linoleic acid (CLA), which are potential lipid prodrugs, were synthesised. CLA was obtained by the alkali-isomerisation of linoleic acid and was subsequently used in the synthesis of 1,2-di(conjugated)linoleoyl-sn-glycero-3-phosphocholine in good (82 %) yield. 1-Palmitoyl-2-(conjugated)linoleoyl-sn-glycero-3-phosphocholine was obtained by a two-step synthesis in 87 % yield. All the compounds were tested in an in vitro cytotoxicity assay against two human cancer cell lines, HL-60 and MCF-7, and a mouse fibroblast cell line, Balb/3T3. The free form of CLA exhibited the highest activity against all cancer cell lines. Results obtained for the Balb/3T3 line proved that phosphatidylcholine derivatives decreased the cytotoxic effect of CLA against healthy cell lines.

Antitumor efficacy of a novel CLA-PTX microemulsion against brain tumors: in vitro and in vivo findings

BACKGROUND

Considering the observations that linoleic acid conjugated with paclitaxel (CLA-PTX) possesses antitumor activity against brain tumors, is able to cross the blood-brain barrier, but has poor water solubility, the purpose of this study was to prepare a novel CLA-PTX microemulsion and evaluate its activity against brain tumors in vitro and in vivo.

METHODS

The in vitro cytotoxicity of a CLA-PTX microemulsion was investigated in C6 glioma cells. The in vivo antitumor activity of the CLA-PTX microemulsion was evaluated in tumor-bearing nude mice and rats. The pharmacokinetics of the CLA-PTX microemulsion were investigated in rats, and its safety was also evaluated in mice.

RESULTS

The average droplet size of the CLA-PTX microemulsion was approximately 176.3 ± 0.8 nm and the polydispersity index was 0.294 ± 0.024. In vitro cytotoxicity results showed that the IC(50) of the CLA-PTX microemulsion was 1.61 ± 0.83 μM for a C6 glioma cell line, which was similar to that of free paclitaxel and CLA-PTX solution (P > 0.05). The antitumor activity of the CLA-PTX microemulsion against brain tumors was confirmed in our in vivo C6 glioma tumor-bearing nude mice as well as in a rat model. In contrast, Taxol(®) had almost no significant antitumor effect in C6 glioma tumor-bearing rats, but could markedly inhibit growth of C6 tumors in C6 glioma tumor-bearing nude mice. The pharmacokinetic results indicated that CLA-PTX in solution has a much longer circulation time and produces higher drug plasma concentrations compared with the CLA-PTX microemulsion. The results of the acute toxicity study showed that the LD(50) of CLA-PTX solution was 103.9 mg/kg. In contrast, the CLA-PTX microemulsion was well tolerated in mice when administered at doses up to 200 mg/kg.

CONCLUSION

CLA-PTX microemulsion is a novel formulation with significant antitumor efficacy in the treatment of brain tumors, and is safer than CLA-PTX solution.

Cis-9,trans-11-conjugated linoleic acid affects lipid raft composition and sensitizes human colorectal adenocarcinoma HT-29 cells to X-radiation

BACKGROUND

Investigations concerned the mechanism of HT-29 cells radiosensitization by cis-9,trans-11-conjugated linoleic acid (c9,t11-CLA), a natural component of human diet with proven antitumor activity.

METHODS

The cells were incubated for 24h with 70μM c9,t11-CLA and then X-irradiated. The following methods were used: gas chromatography (incorporation of the CLA isomer), flow cytometry (cell cycle), cloning (survival), Western blotting (protein distribution in membrane fractions), and pulse-field gel electrophoresis (rejoining of DNA double-strand breaks). In parallel, DNA-PK activity, γ-H2AX foci numbers and chromatid fragmentation were estimated. Gene expression was analysed by RT-PCR and chromosomal aberrations by the mFISH method. Nuclear accumulation of the EGF receptor (EGFR) was monitored by ELISA.

RESULTS AND CONCLUSIONS

C9,t11-CLA sensitized HT-29 cells to X-radiation. This effect was not due to changes in cell cycle progression or DNA-repair-related gene expression. Post-irradiation DSB rejoining was delayed, corresponding with the insufficient DNA-PK activation, although chromosomal aberration frequencies did not increase. Distributions of cholesterol and caveolin-1 in cellular membrane fractions changed. The nuclear EGFR translocation, necessary to increase the DNA-PK activity in response to oxidative stress, was blocked. We suppose that c9,t11-CLA modified the membrane structure, thus disturbing the intracellular EGFR transport and the EGFR-dependent pro-survival signalling, both functionally associated with lipid raft properties.

GENERAL SIGNIFICANCE

The results point to the importance of the cell membrane interactions with the nucleus after injury inflicted by X -rays. Compounds like c9,t11-CLA, that specifically alter membrane properties, could be used to develop new anticancer strategies.

Effects of conjugated linoleic acid and high oleic acid safflower oil in the treatment of children with HPV-induced laryngeal papillomatosis: a randomized, double-blinded and crossover preliminary study

BACKGROUND

Surgery is the mainstay therapy for HPV-induced laryngeal papillomatosis (LP) and adjuvant therapies are palliative at best. Research revealed that conjugated-linoleic acid (CLA) may improve the outcome of virally-induced diseases. The effects of Clarinol™ G-80 (CLA) and high oleic safflower oil (HOSF) on children with LP (concomitant with surgery) were evaluated.

DESIGN

A randomized, double-blinded, crossover and reference-oil controlled trial was conducted at a South African medical university. Study components included clinical, HPV type/load and lymphocyte/cytokine analyses, according to routine laboratory methods.

PARTICIPANTS

Overall: ten children enrolled; eight completed the trial; five remained randomized; seven received CLA first; all treatments remained double-blinded.

INTERVENTION

Children (4 to 12 years) received 2.5 ml p/d CLA (8 weeks) and 2.5 ml p/d HOSF (8 weeks) with a washout period (6 weeks) in-between. The one-year trial included a post-treatment period (30 weeks) and afterwards was a one-year follow-up period.

MAIN OUTCOME MEASURES

Changes in numbers of surgical procedures for improved disease outcome, total/anatomical scores (staging system) for papillomatosis prevention/viral inhibition, and lymphocyte/cytokine counts for immune responses between baselines and each treatment/end of trial were measured.

FINDINGS

After each treatment all the children were in remission (no surgical procedures); after the trial two had recurrence (surgical procedures in post-treatment period); after the follow-up period three had recurrence (several surgical procedures) and five recovered (four had no surgical procedures). Effects of CLA (and HOSF to a lesser extent) were restricted to mildly/moderately aggressive papillomatosis. Children with low total scores (seven/less) and reduced infections (three/less laryngeal sub-sites) recovered after the trial. No harmful effects were observed. The number of surgical procedures during the trial (n6/available records) was significantly lower [(p 0.03) (95% CI 1.1; 0)]. Changes in scores between baselines and CLA treatments (n8) were significantly lower: total scores [(p 0.02) (95% CI -30.00; 0.00)]; anatomical scores [(p 0.008) (95% CI -33.00: -2.00)]. Immune enhancement could not be demonstrated.

CONCLUSIONS

These preliminary case and group findings pave the way for further research on the therapeutic potential of adjuvant CLA in the treatment of HPV-induced LP.