Effect of Antioxidants on Ocular Blood Flow, Endothelial Function, and Cytokine Levels in LPS Induced Inflammatory Model in Humans.

Effect of Antioxidants on Ocular Blood Flow, Endothelial Function, and Cytokine Levels in LPS Induced Inflammatory Model in Humans.

Effect of Antioxidants on Ocular Blood Flow, Endothelial Function, and Cytokine Levels in LPS Induced Inflammatory Model in Humans.

Oxidative stress, which refers to cellular damage caused by reactive oxygen intermediates, has been implicated in many disease processes, especially age-related disorders. Many trials investigating use of antioxidants in protecting different tissues against oxidative stress have been conducted, but the results are ambiguous. Inflammation is generally associated with enhanced oxidative stress and widespread endothelial dysfunction. In the present study, the infusion of LPS, which is a cell wall component of Gram-negative bacteria and a major mediator in the pathogenesis of septic shock, will be used as a standardized experimental model of systemic inflammatory response in humans. The assessment of outcome parameters will include measurements of ocular blood flow, forearm blood flow and plasma concentration of cytokines. Measurements of ocular hemodynamics provide an unique chance to investigate local blood flow in humans non-invasively. Moreover, the retina is especially susceptible to oxidative stress because of its high consumption of oxygen, its high polyunsaturated fatty acid content, and its exposure to visible light. Evidence from literature clearly supports a role for oxidative stress in pathophysiology of several ocular diseases including diabetic retinopathy and age-related macular degeneration. To investigate the retinal vascular reactivity we will use systemic hyperoxia as a stimulus. The measurement of forearm blood flow will be use to assess endothelial function. The main study objective is to investigate the effect of oral vitamins and minerals supplementation on impaired retinal vascular reactivity after LPS administration.

dose: 4 tablets daily for two weeks vitamin A 7160 IU, vitamin C 113mg, vitamin E 100IU, zinc 17.4mg, copper 0.4mg

Inclusion Criteria: Men aged between 18 and 35 years, nonsmokers Body mass index between 15th and 85th percentile Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant Normal laboratory values unless the investigator considers an abnormality to be clinically irrelevant Normal ophthalmic findings, ametropia < 3 Dpt Exclusion Criteria: Regular use of medication, abuse of alcoholic beverages, participation in a clinical trial in the 3 weeks preceding the study Treatment in the previous 3 weeks with any drug, vitamins and minerals supplements as well Symptoms of a clinically relevant illness in the 3 weeks before the first study day History of hypersensitivity to the trial drug or to drugs with a similar chemical structure History or presence of gastrointestinal, liver or kidney disease, or other conditions known to interfere with, distribution, metabolism or excretion of study drugs Blood donation during the previous 3 weeks

Pemp B, Polska E, Karl K, Lasta M, Minichmayr A, Garhofer G, Wolzt M, Schmetterer L. Effects of antioxidants (AREDS medication) on ocular blood flow and endothelial function in an endotoxin-induced model of oxidative stress in humans. Invest Ophthalmol Vis Sci. 2010 Jan;51(1):2-6. doi: 10.1167/iovs.09-3888. Epub 2009 Aug 13.