Conjugated linolenic acid is slowly absorbed in rat intestine, but quickly converted to conjugated linoleic acid

Laboratory of Food and Biomolecular Science, Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555, Japan.
Journal of Nutrition (Impact Factor: 3.88). 08/2006; 136(8):2153-9.
Source: PubMed


We showed previously that alpha-eleostearic acid (alpha-ESA; 9Z11E13E-18:3) is converted to 9Z11E-conjugated linoleic acid (CLA) in rats through a Delta13-saturation reaction. To investigate this further, we examined the absorption and metabolism of alpha-ESA in rat intestine using a lipid absorption assay in lymph from the thoracic duct. In this study, we used 4 test oils [tung oil, perilla oil, CLA-triacylglycerol (TG), and pomegranate seed oil, containing alpha-ESA, alpha-linolenic acid (LnA; 9Z12Z15Z-18:3), CLA, and punicic acid (PA; 9Z11E13Z-18:3), respectively]. Emulsions containing the test oils were administered to rats, and lymph from the thoracic duct was collected over 24 h. The positional and geometrical isomerism of CLA produced by PA metabolism was determined using GC-electron impact (EI)-MS and (13)C-NMR, respectively; the product was confirmed to be 9Z11E-CLA. A part of alpha-ESA and PA was converted to 9Z11E-CLA 1 h after administration; therefore the lymphatic recoveries of alpha-ESA and PA were modified by the amount of recovered CLA. Cumulative recovery of CLA, alpha-ESA, and PA was lower than that of LnA only during h 1 (P < 0.05), and cumulative recovery of alpha-ESA and PA was significantly lower than that of LnA and CLA for 8 h (P < 0.05). Therefore, the absorption rate was LnA > CLA > alpha-ESA = PA. The conversion ratio of alpha-ESA to 9Z11E-CLA was higher than that of PA to 9Z11E-CLA over 24 h (P < 0.05). These results indicated that alpha-ESA and PA are slowly absorbed in rat intestine, and a portion of these fatty acids is quickly converted to 9Z11E-CLA.

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    • "Inside in vivo system however , the action of CLnAs largely depends on its permeability across GI tract which directly implies its bioavailabilty . Moreover , transport of CLnA across GI tract is very slow and involves quick conversion into conjugated linoleic acid ( CLA ) ( Tsuzuki et al . 2006 ) thereby limiting its efficacy . The absorption of CLnA can be improved significantly by converting the lipid fractions comprising them into nanoemulsions due to : i ) the presence of surfactants which enhances penetration across cellular membranes due to its amphiphilicity ( Kreilgaard 2002 ) ; ii ) uptake of hydrophobic bioactive age"
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    ABSTRACT: The present work entailed perspicacious fabrication of Bitter Gourd Seed Oil Nanoemulsion (BGO-NE) for increasing bioavailability of CLnA in oxidative stress induced in vivo system. The BGO-NE was characterized and evaluated for dimensional as well as rheological changes periodically during a 12 week storage period. BGO comprising ∼50 % α-eleostearic acid, was assessed in conventional and NE formulation at different doses, for its ability to stimulate antioxidative enzyme marker paradigm comprising SOD, GPx, CAT and GSH, inherent to the subjects under study. The formulated BGO-NE (d < 100 nm) was found to be stable for 12 weeks compared to BGO-CE as was determined by particle size characterization and associated parameters. Diet supplementation of 0.5 % (w/v) BGO-NE formulation exhibited maximum efficiency in countering oxidative stress as compared to 1 % BGO-NE formulation and equivalent doses of BGO-CE. Higher efficacy at very low dose of the nano-sized formulation was thus, also established. Histopathological data from liver, pancreas and kidney sections corroborated the above findings. The present study with formulated BGO-NE and BGO-CE evaluates and confirms the implications of a NE formulation of a bioactive lipid - conjugated linolenic acid (CLnA), targeting specific in vivo processes to counter the negative influence of excess ROS (Reactive Oxygen Species) in the system. It, thus presents itself as a potent nutraceutical against diabetes mellitus in an optimized delivery system.
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    • "Other health potentials of CLA are antiathergenic, antidiabetogenic and immune modulating properties [13]. They are the only conjugated fatty acids that can be prepared in large quantities from natural sources [14]. Conjugated linolenic acids (CLnA) are octadecatrienoic acids with three conjugated double bonds. "
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    ABSTRACT: Essential fatty acids (EFA) are a group of unsaturated fatty acids which are not produced in humans, but are necessary for the proper functioning of the human body. It is mostly found in vegetable oils, seeds and nuts. They have shown diverse medicinal properties and potential beneficial effects on diseases such as cancer, insulin resistance, skin permeability, cardiovascular disease and depression. Fatty acids have the potential to inhibit the fatty acid biosynthetic machinery of Plasmodium falciparum parasite. In the present work, in vitro antiplasmodial activity of linoleic and linolenic acids using PLDH assay, against D10 and Dd2 strains of the parasite was <10 µg/ml. Linolenic and linoleic acids inhibited parasites growth by 70% and 64% respectively, against P.berghei using the 4-day suppressive test. The two compounds when used in combination inhibited the parasites by 96% on day 4 of treatment. No significant difference was observed between the free acids and their methyl esters.
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    • "Interestingly, CLnA can be converted to CLA; e.g. c9,t11,t13-CLnA and c9,t11,c13-CLnA to c9,t11-CLA in rats [17] and c9,t11,c13-CLnA to c9,t11-CLA in humans [18]. "
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    ABSTRACT: Conjugated fatty acids (CFAs) exhibit growth inhibitory effects on colon cancer in vitro and in vivo. To investigate whether the anticancerogenic potency depends on number or configuration of the conjugated double bonds, the effect of conjugated linoleic acid (CLA; C18:2) isomers and conjugated linolenic acid (CLnA; C18:3) isomers on viability and growth of HT-29 cells were compared. Low concentrations of CLnAs (<10μM) yielded a higher degree of inhibitory effects compared to CLAs (40μM). All trans-CFAs were more effective compared to cis/trans-CFAs as follows: t9,t11,t13-CLnA≥c9,t11,t13-CLnA>t11,t13-CLA≥t9,t11-CLA>c9,t11-CLA. The mRNA expression analysis of important genes associated with fatty acid metabolism showed an absence of ∆5-/∆6-desaturases and elongases in HT-29 cells, which was confirmed by fatty acid analysis. Using time- and dose-dependent stimulation experiments several metabolites were determined. Low concentrations of all trans-CFAs (5-20μM) led to dose-dependent increase of conjugated t/t-C16:2 formed by β-oxidation of C18 CFAs, ranging from 1-5% of total FAME. Importantly, it was found that CLnA is converted to CLA and that CLA is inter-converted (t11,t13-CLA is metabolized to c9,t11-CLA) by HT-29 cells. In summary, our study shows that growth inhibition of human cancer cells is associated with a specific cellular transcriptomic and metabolic profile of fatty acid metabolism, which might contribute to the diversified ability of CFAs as anti-cancer compounds.
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