Birgit Holst
Nestlé
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Publication
Featured researches published by Birgit Holst.
Natural Product Reports | 2004
Birgit Holst; Gary Williamson
Glucosinolates (GLSs) are relatively inert (Z)-N-hydroximinosulfate esters, possessing a sulfur-linked beta-D-glucopyranose moiety and a variable side chain, found almost exclusively in cruciferous vegetables. Following cell disruption, they are hydrolysed by plant myrosinases, forming a group of chemically reactive and biologically active compounds. There is considerable evidence that these breakdown products, when consumed in the diet, may affect the risk of developing chronic diseases. However, in order for any compound to exert an activity in vivo, it is necessary to reach the site of action in an appropriate form and sufficient concentration. Deleterious and toxic effects may be observed at high concentrations: hence, bioavailability is a key factor defining the physiological, beneficial dose window of GLS hydrolysis products (GLS-HPs). For some GLS-HPs, this window can be rather narrow, and therefore is a critical parameter to be considered. In this review we critically evaluate the present state of knowledge on all factors that affect bioavailability of GLS-HPs. This includes liberation from the plant material, absorption from the digestive system, distribution around the body, metabolism and excretion.
Chimia | 2014
Kornél Nagy; Beatriz Lobo; Marie-Claude Courtet-Compondu; Sophie Braga-Lagache; Laura Ramos; Valentí Puig-Diví; Fernando Azpiroz; Juan R. Malagelada; Maurice Beaumont; Julie Moulin; Simone Acquistapace; Laurent Sagalowicz; Martin Kussmann; Javier Santos; Birgit Holst; Gary Williamson
We determined the bioavailability of vitamin E from self-assembly structures in patients with diagnosed chronic pancreas insufficiency. Vitamin E solubilized in dispersed inverted bicontinuous cubic phase and in micellar formulation was delivered directly to the small intestine by tube-feeding. A cross-over study with randomization of 6 subjects and 2 treatments including a combined dose of 18 mg (27 IU) of vitamin E (RRR-[5,7-methyl-((2)H6)]-α-tocopherol) and 27 mg (27 IU) vitamin E acetate (RRR-[5-methyl-(2)H3]-α-tocopheryl acetate) was applied over a time period of 1 h. Plasma samples were collected for 56 h and analyzed by liquid chromatography-mass spectrometry. Appearance of labeled tocopherols originating from the treatment started at 25 h and reached Cmax (0.6-4.6 μM depending on subject) in the 7-9 h window. From the Tmax onwards, both forms of tocopherols diminished slowly to 30-50% of their maxima within 56 h. Strong inter-individual variation was observed in the plasma appearance curves (relative standard deviation varied between 38-45%). No significant discrimination was found between the absorption of free or acetylated forms of deuterated α-tocopherol confirming that application of acetylated α-tocopherol provides the same bioavailability as free α-tocopherol. This observation is valid in both dispersed inverted bicontinuous cubic phase and micellar formulations. Furthermore, since the area-under-the-curve values from cubic phase and from micellar formulations are similar, the cubic phase formulation could represent an alternative delivery system for lipophilic micronutrients in conditions or studies where polysorbate-based micelles cannot be generated.
Current Opinion in Biotechnology | 2008
Birgit Holst; Gary Williamson
Drug Metabolism and Disposition | 2003
Niclas Petri; Christer Tannergren; Birgit Holst; Fred A. Mellon; Yongping Bao; Geoff W. Plumb; Jim Bacon; Karen A. O'Leary; Paul A. Kroon; Lars Knutson; Patrik Forsell; Thomas Eriksson; Hans Lennernäs; Gary Williamson
Analytical Biochemistry | 2002
Fred A. Mellon; Richard N. Bennett; Birgit Holst; Gary Williamson
British Journal of Nutrition | 2008
Gary Williamson; Birgit Holst
Archive | 2006
Laurent Sagalowicz; Martin E. Leser; Martin Michel; Heribert Watzke; Simone Acquistapace; Raymond Bertholet; Birgit Holst; Fabien Robert
Mass Spectrometry Reviews | 2007
Martin Kussmann; Michael Affolter; Kornél Nagy; Birgit Holst; Laurent B. Fay
Analytical Chemistry | 2007
Kornél Nagy; Marie-Claude Courtet-Compondu; Birgit Holst; Martin Kussmann
Journal of Labelled Compounds and Radiopharmaceuticals | 2001
Nikolai Kuhnert; Birgit Holst; Gary Williamson