Nicolas Cardinault

Simple method for clinical determination of 13 carotenoids in human plasma using an isocratic high-performance liquid chromatographic method.

We report a reversed-phase high-performance liquid chromatography method which resolves 13 identified carotenoids and nine unknown carotenoids from human plasma. A Nucleosil C18 column and a Vydac C18 column in series are used with an isocratic solvent system of acetonitrile-methanol containing 50 mM acetate ammonium-dichloromethane-water (70:15:10:5, v/v/v/v) as mobile phase at a flow-rate of 2 ml/min. The intra-day (4.5-8.3%) and inter-day (1.3-12.7%) coefficients of variation are suitable for routine clinical determinations.

Short-term supplementation with lutein affects biomarkers of lutein status similarly in young and elderly subjects.

There is evidence that lutein may protect against age-related macular degeneration, cataract, cancers and cardiovascular diseases, but no data have been published on the effect of age on lutein status. The purpose of this work was to determine whether there are major differences in the status of this carotenoid between young and elderly subjects. Initial lutein status and the effect of a 5-week lutein supplementation (9 mg/d) on the most common markers of lutein status were compared in 12 young (26.9+/-0.8yr) and 17 older subjects (67.3+/-1.1yr). Lutein was measured by HPLC in fasting serum, adipose tissue and buccal mucosa cells (BMC) before and after supplementation. Macular pigment optical density (MPOD), which partly depends on retina lutein concentration, was measured by reflectometry before and after supplementation. Initial lutein status was not significantly different between the two groups, irrespective of the lutein status marker. Plasma and BMC lutein concentrations significantly increased in both groups after lutein supplementation, but not MPOD or adipose tissue lutein. Plasma and BMC responses to lutein supplementation (percent variation from initial values) were not significantly different between the two groups. These results suggest that there is no major effect of age on lutein status in healthy subjects.

Increased concentrations of circulating vitamin E in carriers of the apolipoprotein A5 gene −1131T>C variant and associations with plasma lipids and lipid peroxidation

The aim of this study was to investigate the effects of the apolipoprotein A5 (APOA5) 1131T>C gene variant on vitamin E status and lipid profile. The gene variant was determined in 297 healthy nonsmoking men aged 20–75 years and recruited in the VITAGE Project. Effects of the genotype on vitamin E in plasma, LDL, and buccal mucosa cells (BMC) as well as on cholesterol and triglyceride (TG) concentrations in plasma and apolipoprotein A-I (apoA-I), apoB, apoE, apoC-III, and plasma fatty acids were determined. Plasma malondialdehyde concentrations as a marker of in vivo lipid peroxidation were determined. C allele carriers showed significantly higher TG, VLDL, and LDL in plasma, higher cholesterol in VLDL and intermediate density lipoprotein, and higher plasma fatty acids. Plasma α-tocopherol (but not γ-tocopherol, LDL α- and γ-tocopherol, or BMC total vitamin E) was increased significantly in C allele carriers compared with homozygote T allele carriers (P = 0.02), but not after adjustment for cholesterol or TG. Plasma malondialdehyde concentrations did not differ between genotypes. In conclusion, higher plasma lipids in the TC+CC genotype are efficiently protected against lipid peroxidation by higher α-tocopherol concentrations. Lipid-standardized vitamin E should be used to reliably assess vitamin E status in genetic association studies.

Bee Pollen Improves Muscle Protein and Energy Metabolism in Malnourished Old Rats through Interfering with the Mtor Signaling Pathway and Mitochondrial Activity

Although the management of malnutrition is a priority in older people, this population shows a resistance to refeeding. Fresh bee pollen contains nutritional substances of interest for malnourished people. The aim was to evaluate the effect of fresh bee pollen supplementation on refeeding efficiency in old malnourished rats. Male 22-month-old Wistar rats were undernourished by reducing food intake for 12 weeks. The animals were then renourished for three weeks with the same diet supplemented with 0%, 5% or 10% of fresh monofloral bee pollen. Due to changes in both lean mass and fat mass, body weight decreased during malnutrition and increased after refeeding with no between-group differences (p < 0.0001). Rats refed with the fresh bee pollen-enriched diets showed a significant increase in muscle mass compared to restricted rats (p < 0.05). The malnutrition period reduced the muscle protein synthesis rate and mTOR/p70S6kinase/4eBP1 activation, and only the 10%-pollen diet was able to restore these parameters. Mitochondrial activity was depressed with food restriction and was only improved by refeeding with the fresh bee pollen-containing diets. In conclusion, refeeding diets that contain fresh monofloral bee pollen improve muscle mass and metabolism in old, undernourished rats.

Does aging affect the response of vitamin E status to vitamin E depletion and supplementation

Abstract: A vitamin E depletion/supplementation study was conducted in 100 healthy 20‐75‐year‐old volunteers. The responses of vitamin E status to 3‐week dietary vitamin E restriction to approximately 25% of recommended intake and 2‐month unrestricted dietary intake plus 800 IU/d of RRR‐α‐tocopherol were studied as a function of age. Plasma α‐tocopherol concentrations were closely related to cholesterol concentrations, which increased with age (P < 0.001). Upon dietary restriction, plasma α‐tocopherol concentrations decreased significantly (P < 0.001) but independently of age. Plasma α‐tocopherol responses to supplementation increased significantly with age, but this effect disappeared after standardization for cholesterol. γ‐Tocopherol concentrations decreased to less than 30% of baseline.