Novel HPLC analysis of tocopherols, tocotrienols, and cholesterol in tissue

Natural aging is accompanied by a dysregulation of the host immune response that has well-known clinical consequences but poorly defined underlying causes. It has previously been reported that advancing age is associated with an increase in membrane cholesterol level in T cells. The aim of this study was to investigate whether high-density lipoprotein (HDL) can modulate the age-related accumulation of membrane cholesterol in T cells and impact on their subsequent responsiveness. Our data reveal that cholesterol metabolism, influx, and efflux are altered in T cells with aging, which may in part explain the increase in membrane cholesterol level observed in T cells in elderly individuals. HDL was unable to promote reverse cholesterol transport in T cells from elderly subjects with the same efficiency as was observed in T cells from young subjects besides unchanged ABCA-1 and SR-BI expressions. HDL exhibited a short-acting co-stimulatory effect by enhancing T cell production of interleukin-2 (IL-2). Moreover, HDL from healthy normolipemic individuals exerted differential effects on T cell proliferation that depended on the age of the HDL donor. Finally, HDL modulated TCR/CD28 activation by inducing sustained signaling through pLck, pERK, and pAkt. These data suggest that HDL has immunomodulatory effects on T cells that are influenced by age.

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“…We used the HPLC method described by de Mello et al (2004) and Katsanidis and Addis (1999) with some modifications (Larbi et al 2006a).…”

Section: Membrane Cholesterol and Fluidity Measurementmentioning

confidence: 99%

Immunomodulatory role of high-density lipoproteins: impact on immunosenescence

Larbi

Fortin

Dupuis

et al. 2014

AGE

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“…The tocopherols were quantified by the HPLC method (Katsanidis, 1999), which consisted of a Knauer pump and a knauer and smartline 2500 UV detector (Advanced Scientific Instrument, Berlin, Germany). Acorn oil samples were dissolved in n-hexane 0.36% (w/v), 20 µL of the solution was injected into a silica column (thermoQuest, 10 µ particle size, 4.0 mm ID × 30 cm).…”

Section: Tocopherols Analysismentioning

confidence: 99%

Characterization of Acorn Fruit Oils Extracted from Selected Mediterranean Quercus Species

Al-Rousan¹,

Ajo²,

Al‐Ismail³

et al. 2013

Grasas y Aceites

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El presente estudio tuvo como objetivo identificar la composición de aceites de bellota de tres especies del grupo del roble blanco del Mediterráneo, Quercus Aegilops (QA), Quercus infectoria (QI) y Quercus calliprinus (QC). Las muestras fueron evaluadas por el contenido de aceite, pará-metros físico-químicos del aceite, perfil de ácidos grasos, tocoferoles, compuestos fenólicos y esteroles. El contenido de aceite, expresado en peso seco encontrado fue de 3,40 a 7,51%. Las constantes físico-químicas fueron: densidad 0,912-0,922, índice de refracción 1,4529 a 1,4645, extinción específica a 232 nm 2,497-2,536 y a 270 nm 1,495-2,037, índice de yodo 75,2-87,6, e índice de saponificación 192,6-219,4. Las composiciones de ácidos grasos se determinaron por GC como ésteres metilicos. Los ácidos grasos más abundantes fueron oleico 53,3-56,1%, linoleico 21,3-23,4%, palmítico 17,8-18,7%, linolénico 1.5-1.6% y esteárico 1,02-1,60%. El contenido de tocoferoles fue alto: 1440-1783 mg kg -1 , constituyendo el γ-tocoferol entre el 84-91% de los tocoferoles totales. Los compuestos fenólicos estaban presentes en cantidades notables en las tres especies 84-109 mg de ácido gálico kg -1 aceite. El contenido total de esteroles fue de 2040-2480 mg kg -1 de aceite, siendo el β-sitosterol el componente principal que comprende de 77,2-84,6%, seguido de la Δ5-avenasterol 5.8-11.4, campesterol 3.6-4.5%, y estigmasterol 2.6-3.8%.El contenido de colesterol fue relativamente alto (0,42-0,55%). PALABRAS CLAVE: Aceite de bellota -Compuestos fenólicos -Esteroles -Perfil de ácidos grasos -Quercus spp. -Tocoferoles. SUMMARY Characterization of Acorn Fruit Oils Extracted from Selected Mediterranean Quercus SpeciesThe present study is aimed to identifying the acorn fruit oil composition of three Mediterranean white oak group species, Quercus aegilops (QA), Quercus infectoria (QI), and Quercus calliprinus (QC). Samples were estimated for the oil contents of acorn fruits, oil chemical and physical constants, fatty acid profile, tocopherols, phenolic compounds, and sterols.The oil content, expressed as dry weight, was found to be 3.40-7.51%. The physical and chemical constants included specific gravity 0.912-0.922, refractive index 1.4529-1.4645, specific extinction at 232 nm 2.497-2.536 and at 270 nm 1.495-2.037, iodine value 75.2-87.6, and saponification value 192.6-219.4. The fatty acid compositions were determined by GC as methyl esters. The most abundant fatty acids were oleic (53.3-56.1%), linoleic 21.3-23.4%, palmitic 17.8-18.7%, linolenic 1.5-1.6% and stearic acid 1.02-1.60%. The Tocopherol content was high in the range of 1440-1783 mg kg -1 , γ-tocopherol constituted 84-91% of total tocopherols. Phenolic compounds were in remarkable amounts in all the three species 84-109 mg gallic acid kg -1 oil. Total sterol contents were between 2040-2480 mg kg -1 oil, with β-sitosterol being the main component comprising of 77.20-84.61%, followed by Δ 5 -avenasterol (5.8-11.4%), campesterol (3.6-4.5%), and stigmasterol (2.6-3.8). The cholesterol content wa...

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“…Extraction of lipids from tissue specimens was carried out with Hara and Radin (1978) according to what Katsanidis and Addis (1999) reported. One section of lipid extraction phase which was divided into two sections was put into tubes with caps and 5% KOH solution was added (KOH solution was prepared in 100% ethanol).…”

Section: Lipid Extractionmentioning

confidence: 99%