Enhanced bioavailability of zeaxanthin in a milk-based formulation of wolfberry (Gou Qi Zi;Fructus barbarum L.)

The carotenoid zeaxanthin is concentrated within the macula. Increased macular zeaxanthin is suggested to lower the risk of age-related macular degeneration. The small red berry, wolfberry (Fructus barbarum L.; Gou Qi Zi and Kei Tze), is one of the richest natural sources of zeaxanthin. However, carotenoid bioavailability is low, and food-based products with enhanced bioavailability are of interest. The present study investigated zeaxanthin bioavailability from three wolfberry formulations. Berries were homogenised in hot (80°C) water, warm (40°C) skimmed milk and hot (80°C) skimmed milk, with freeze drying of each preparation into a powdered form. A zeaxanthin-standardised dose (15mg) of each was consumed, in randomised order, together with a standardised breakfast by twelve healthy, consenting subjects in a cross-over trial, with a 3-5-week washout period between treatments. Blood samples were taken via a venous cannula immediately before (fasting) and 2, 4, 6, 7, 8 and 10h post-ingestion. Zeaxanthin concentration in the triacylglycerol-rich lipoprotein fraction of plasma was measured by HPLC. Results showed that triacylglycerol-rich lipoprotein zeaxanthin peaked at 6h post-ingestion for all formulations. Zeaxanthin bioavailability from the hot milk formulation was significantly higher (p<0·001) than from the others. Mean area under the curve (n 12) results were 9·73 (sem 2·45), 3·24 (sem 0·72) and 3·14 (sem 1·09) nmol×h/l for the hot milk, warm milk and hot water formulations, respectively. Results showed clearly that homogenisation of wolfberry in hot skimmed milk results in a formulation that has a 3-fold enhanced bioavailability of zeaxanthin compared with both the ‘classical' hot water and warm skimmed milk treatment of the berrie

Antioxidant power of angiotensin-converting enzyme inhibitors in vitro

Aims. There is controversy regarding the potential antioxidant effect of captopril, therefore this study was performed to compare the in vitro antioxidant power of captopril with other angiotensin-converting enzyme (ACE) inhibitors. Methods. Antioxidant power of captopril, enalapril, fosinopril, perindopril, quinapril and ramipril in aqueous solution was measured using the ferric reducing (antioxidant) power (FRAP) assay; captopril was also measured in ethanolic solution. Results. Only captopril showed significant antioxidant power, demonstrating a stoichiometric factor of 1.0 in this assay. Concentration-related antioxidant power was seen in both aqueous and ethanolic solutions. Conclusions. Captopril shows antioxidant activity in vitro. This property could be relevant in vivo if captopril is concentrated in membranes, lipoproteins or at other important sites.Department of Health Technology and Informatic

Herbal and traditional medicine.

Rev. ed. of: Herbal and traditional medicine / edited by Lester Packer, Choon Nam Ong, Barry Halliwell. c2004.Includes bibliographical references and index.Book fair 2012xxi, 473 p. :"Responding to the increased popularity of herbal medicines and other forms of complementary or alternative medicine in countries around the world, this reference reviews and evaluates various safety, toxicity, and quality-control issues related to the use of traditional and herbal products for health maintenance and disease prevention and treatment. With over 3,550 current references, the book highlights the role of herbal medicine in national health care while providing case studies of widely used herbal remedies and their effects on human health and wellness and the need for the design and performance of methodologically sound clinical trials for the plethora of herbal medicines"--Provided by publisher

The Ferric Reducing Ability of Plasma (FRAP) as a measure of antioxidant power: The FRAP assay.

destroy potential oxidants, and to scavenge ROS. Thus, A simple, automated test measuring the ferric reduc-oxidative stress-induced tissue damage is minimized. ing ability of plasma, the FRAP assay, is presented as However, an absolute or relative deficiency of antioxia novel method for assessing &apos;&apos;antioxidant power.&apos;&apos; Fer-dant defenses may lead to a situation of increased oxiric to ferrous ion reduction at low pH causes a colored dative stress, and this may be associated with both ferrous-tripyridyltriazine complex to form. FRAP val-the causes and consequences of a variety of disorders, ues are obtained by comparing the absorbance change including coronary heart disease and cancer (6-13). at 593 nm in test reaction mixtures with those con- Tests which measure the combined antioxidant effect taining ferrous ions in known concentration. Ab-of the nonenzymatic defenses in biological fluids may sorbance changes are linear over a wide concentration be useful in providing an index of ability to resist oxidarange with antioxidant mixtures, including plasma, tive damage (13-19). Most tests of &apos;&apos;total antioxidant and with solutions containing one antioxidant in puri-power&apos;&apos; used to date have measured the ability of fied form. There is no apparent interaction between plasma to withstand the oxidative effects of reactive antioxidants. Measured stoichiometric factors of Tro-species purposefully generated in the reaction mixture