Simultaneous Measurement of Carotenoids and Vitamins A and E in Human Serum by High Performance Liquid Chromatography (HLPC) and the Effect of Consuming Eggs on Serum Carotenoid and Lipid Concentrations and Macular Degeneratio

The aims of this project were to: (1) develop a simultaneous measurement and identification of carotenoids, tocopherols, and retinol concentrations in human serum using a new C30 ProntoSlL Column by High Performance Liquid Chromatography (HPLC); (2) determine if the consumption of 12 store-bought eggs per week for 1 year will raise serum lutein and zeaxanthin levels and MPOD while preventing the progression of AMD in individuals with early to intermediate stages of Dry AMD; (3) determine if the consumption of 12 store-bought eggs per week for 1 year will raise serum lipid, lipoprotein cholesterol, and other cardiovascular disease (CVD) related biochemical concentrations in these individuals; and (4) determine if the consumption of a meal containing high amounts of lutein and zeaxanthin, which may occur with the consumption of 12 eggs per 1 week, alters the serum concentration of other important carotenoids as well as vitamins A and E.;Previously, HPLC instruments utilizing a C18 300 x 4.6 mm column was needed to separate and identify the various isomers of carotenoids from human serum. In the first experiment, an HPLC method utilizing a new C30 ProntoSIL 250 x 4.6 mm column, at 22°C, a flow rate of 0.5 mL/min, and an injection volume of 30 microL with an 80 minute running time was optimized for the determination of the various carotenoid isomers, tocopherols, and retinol simultaneously in human serum. A diode array detector (DAD) was used to measure serum carotenoids (set at a wavelength of 450 nm) and retinol (set at a wavelength of 325 rim) while a fluorescent detector was used to measure tocol (internal standard) and various tocopherols (set at an excitation wavelength of 290 nm and an emission wavelength of 330 nm).;The next phase of the project involved identifying if the consumption of 12 eggs per week for 1 year produces changes in serum lutein and zeaxanthin concentrations and on MPOD and the progression of AMD in patients previously diagnosed with early AMD. Forty-five adults were randomized to the intervention (n=27) or control (n=18) group. Serum lutein, zeaxanthin and MPOD for both eyes were measured at 0 and 12 months. Results showed greater increases in lutein (52% vs. 6%) and zeaxanthin (83% vs. 0%) in the intervention group compared to the control group, however only serum zeaxanthin concentrations changed significantly.;Since recent studies have suggested that eating 1 or more eggs daily may increase risk of death from cardiovascular disease nearly as much as smoking, the third experiment examined the effects of consuming 12 eggs per week for 1 year on serum concentration of lipids, lipoprotein cholesterol, C-reactive protein (CRP), apolipoprotein (Apo)-A1 and B, and glucose. Results showed greater increases in HDL and LDL, 6.25% and 3.3% respectively, in the intervention group. The intervention group's apolipoprotein Al, C-reactive protein, total cholesterol, and triglycerides levels increased, while apolipoprotein ratio (B/A1) and lipoprotein (a) levels decreased.;Lastly, it is possible that eating a meal or a supplement containing a high concentration of certain individual carotenoids (polar vs nonpolar) may cause a reduction in the other carotenoids in the serum simultaneously. This experiment investigated how a diet of 12 eggs per week for 1 year influenced the serum alpha-cryptoxanthin, beta-cryptoxanthin, lycopene, alpha-carotene, beta-carotene, alpha-tocopherol, and retinol concentrations in the subjects. A group of 45 adults were randomized to intervention (n=27) and control (n=18) groups. Serum carotenoid and vitamin levels were obtained at the beginning and at the end of the 12-months trial period. Results showed a statistically significant 18% increase in alpha-carotene level in the control group, and no significant increase in serum levels of any other carotenoid, tocopherol, or retinol in both control and intervention groups. In addition, beta-carotene levels decreased in control and intervention groups, - 9% and -18% respectively.