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Human Low-density Lipoprotein (human + low-density_lipoprotein)
Selected AbstractsImmunological Detection of in Vitro Formed Phosphatidylethanol,An Alcohol Biomarker,With Monoclonal AntibodiesALCOHOLISM, Issue 6 2008Antti E. Nissinen Background:, Phosphatidylethanol (PEth) is a promising new marker for detecting long-term alcohol abuse with excellent sensitivity and specificity. Current methods are based on the high performance liquid chromatography,mass spectrometric method and therefore require high levels of expertise and expensive instrumentation. This study was designed to generate PEth-specific monoclonal antibodies for PEth immunoassay development. Methods:, C57/BL6 mice were immunized with PEth in 3 different carriers, mouse serum albumin, mouse high-density lipoproteins, and human low-density lipoprotein (LDL). Mouse splenocytes were fused with a mouse myeloma cell line using the hybridoma technique. Mouse IgM-producing cell lines were selected by limiting dilutions. Binding characteristics of the anti-PEth antibodies were studied using luminometric immunoassays and sequence analysis of the variable region mRNA sequences of the antibodies. Produced antibodies were purified by chromatographic methods. PEth was detected with these antibodies in fluorescence immunoassay and flow cytometric analysis. Results:, We generated monoclonal cell lines (2B1 and 2E9) that produce IgM antibodies binding specifically to PEth but not to structurally or chemically similar phospholipids, such as phosphatidylcholine, phosphatidic acid, and cardiolipin. We show here that these anti-PEth antibodies can be used to detect PEth in a fluorescent PEth assay and FACS analysis of human red blood cell samples spiked with PEth. Conclusions:, The present study shows that PEth-specific monoclonal antibodies can be generated using traditional hybridoma technique. Immunogenicity of PEth was enhanced using human LDL as an immunization carrier. The generated monoclonal anti-PEth antibodies, 2B1 and 2E9 bind to PEth in fluid phase and in biological membranes. [source] Berry anthocyanins: isolation, identification and antioxidant activities,JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2003Marja P Kähkönen Abstract Anthocyanins from bilberry, blackcurrant and cowberry were isolated for antioxidant evaluation. Individual compounds were identified and quantified using HPLC and HPLC/ESI,MS techniques. Antioxidant and radical-scavenging capacities of the isolates were studied in emulsified methyl linoleate and human low-density lipoprotein (LDL) in vitro and in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test. The total anthocyanin contents in the phenolic extracts of bilberry, blackcurrant and cowberry were 6000, 2360 and 680 mg kg,1 fresh weight respectively. There were four dominant compounds in blackcurrant (glucosides and rutinosides of cyanidin and delphinidin), three in cowberry (monoglycosides of cyanidin) and 15 in bilberry (monoglycosides of cyanidin, delphinidin, malvidin, peonidin and petunidin). Quantification as cyanidin-3-glucoside equivalents gave markedly lower results regarding the total anthocyanin concentration and the content of individual delphinidin and malvidin compounds compared with quantification based on corresponding standard compounds. Berry anthocyanins were highly active radical scavengers in the DPPH test and effective antioxidants in emulsion and human LDL. Copyright © 2003 Society of Chemical Industry [source] Antioxidative activity and ameliorative effects of memory impairment of sulfur-containing compounds in Allium speciesBIOFACTORS, Issue 2 2006Hiroyuki Nishimura Abstract The antioxidative activity and ameliorative effects on memory impairment by sulfur-containing compounds which occur in Allium vegetables such as onion and garlic were investigated. The antioxidative activities of S-alk(en)yl-L-cysteines and their sulfoxides, volatile alk(en)yl disulfides and trisulfides, and vinyldithiins were examined by using human low-density lipoprotein. It was elucidated that the alk(en)yl substituents and the number of sulfur atoms in the compounds were important for the antioxidative activities. To demonstrate the ameliorative effects on memory impairment, onion extract and synthesized di-n-propyl trisulfide were administered to senescence-accelerated mouse P8. The behavioral experiments showed that onion extract and di-n-propyl trisulfide had highly ameliorative effect of memory impairment. Furthermore, it was found that the hippocampus lipid hydroperoxide in senescence-accelerated mouse P8 was decreased by the administration of di-n-propyl trisulfide. These results suggest that di-n-propyl trisulfide contained in onion ameliorates memory impairment in SAMP8 mouse by its antioxidant effect. [source] Antioxidative activity of sulfur-containing compounds in Allium species for human LDL oxidation in vitroBIOFACTORS, Issue 1-4 2004Hiroyuki Nishimura Abstract Sulfur-containing compounds contributing to health promotion in Allium species are produced via enzymic and thermochemical reactions. Sulfur-containing amino acids and volatile organosulfur compounds were prepared for an antioxidative assay. The inhibitory activity of S-alk(en)yl-L-cysteines and their sulfoxides, volatile alk(en)yl disulfides and trisulfides, and vinyldithiins in Allium species against lipid hydroperoxide (LOOH) formation in human low-density lipoprotein (LDL) was examined. It was elucidated that the alk(en)yl substituents (methyl, propyl, and allyl) and the number of sulfur atoms in the compounds were important for the antioxidative activity. 3,4-Dihydro-3-vinyl-1,2-dithiin, which is produced by a thermochemical reaction of allyl 2-propenethiosulfinate, exhibited the highest antioxidative activity of human LDL among sulfur-containing compounds. [source] Ascorbic acid improves the antioxidant activity of European grape juices by improving the juices' ability to inhibit lipid peroxidation of human LDL in vitroINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 7 2001Anne-Katrine Landbo Antioxidant activities of red and white European grape juices towards copper induced lipid oxidation of human low-density lipoproteins (LDL) were examined in vitro. LDL lipid peroxidation was assessed spectrophotometrically by monitoring the development of conjugated lipid hydroperoxides at 234 nm. Red grape juice concentrate inhibited lipid peroxidation of LDL by prolonging the lag phase by 2.7 times relative to a control when evaluated at a total phenolic concentration of 10 ,M gallic acid equivalents (GAE). Both red grape juices tested blocked lipid peroxidation of LDL at 20 ,M GAE. White grape juice exerted prooxidant activity at 5,20 ,M GAE. The antioxidant activity, inhibition of lipid peroxidation of LDL in vitro, was correlated with the juices' levels of total phenols (r > 0.98, P < 0.01), anthocyanins (r > 0.99, P < 0.01), flavan-3-ols (r > 0.97, P < 0.05), and hydroxybenzoates (r > 0.96, P < 0.05) when the phenolic composition of each grape juices was analysed by HPLC. 5 ,M ascorbic acid alone did not exert antioxidant activity towards LDL, but combinations of 5 ,M ascorbic acid with 5 ,M GAE juice phenols eliminated the prooxidant activity of white grape juice, and significantly improved the antioxidant activities of red grape juices. [source] Storage affects the phenolic profiles and antioxidant activities of cherries (Prunus avium L) on human low-density lipoproteinsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2004Berta Gonçalves Abstract Four sweet cherry cultivars (cvs), Burlat, Saco, Summit and Van, were analysed at harvest and after storage at 2 and 15 °C for 30 and 6 days respectively. Phenolic profiles in methanolic extracts of freeze-dried samples of the fresh and differently stored cherries were quantified by high-performance liquid chromatography. Hydroxycinnamates dominated in all samples and represented 60,74% by weight of the phenols in the fresh and stored samples of the cvs Saco, Summit and Van, and 45% by weight of the phenols in the cv Burlat samples, which were richer in anthocyanins. The relative and total levels of hydroxycinnamates, anthocyanins, flavonols and flavan-3-ols varied among cultivars and during storage. Storage at 15 °C increased the phenol levels, particularly the cyanidin-3-rutinoside concentration. Cold storage induced decreased total phenol levels in the cvs Summit and Van but increased total phenol levels in the cvs Burlat and Saco. Phenolic cherry extracts inhibited low-density lipoprotein oxidation in vitro in a dose-dependent manner. Extracts of freshly harvested cherries exhibited significantly higher antioxidant activities than extracts of stored samples. The cv Summit samples had the highest antioxidant activity. Differences in the antioxidant effects of the cherry samples were positively correlated with their levels of p -coumaroylquinic acid (p < 0.1) but negatively correlated with their cyanidin-3-rutinoside levels (p < 0.05). Copyright © 2004 Society of Chemical Industry [source] | ||||||||||