Animal Science Building Rm 256
675 Observatory Drive
Madison, WI 53706
Biochemical & Molecular Nutrition
Principal Research Interest:
Flavonoids and other phytochemicals in animal and human health and nutrition
Flavonoids are common constituents in foods and feeds of plant origin. There are 14 subclasses of flavonoids, but flavonols, anthocyanins and proanthocyanidins (PA) are most common. Evidence that flavonoids protect against coronary artery disease and cancer has been demonstrated through in vitro studies, animal models and studies with human subjects. However, the results are often circumstantial because the studies are done using in vitro models or using whole foods and beverages that contain complex mixtures of flavonoids, polyphenols and other phytochemicals. Research on the role of flavonoids in health and nutrition is severely constrained by the lack of analytical methods that relate the complexity of mixtures and the degree of variation that are found in foods and beverages to their biomedical effects.
Our laboratory does research to determine quantitative and qualitative composition of flavonoids in human food and animal feeds. We also study the absorption and excretion of flavonoid metabolites through in vivo and in vitro experiments. Our current research is focussed on the effects of flavonoids on the development of atherosclerosis, using swine as a model species for humans. Oxidized low density lipoprotein (LDL) is a causative factor in the development of atherosclerosis. In collaboration with Prof. Wiebe of the Medical School, we have found that flavonoid fractions from food sources differ in their ability to protect LDL from oxidation. Fractions that contain PA have the greatest inhibition of Cu+2 induced in vitro LDL oxidation (figure).
Figure: Inhibition of LDL oxidation by proanthocyanidins (Fractions 5 and 6).
Metzger BT, Barnes DM, Reed JD. Insoluble fraction of buckwheat (Fagopyrum esculentum Moench) protein possessing cholesterol-binding properties that reduce micelle cholesterol solubility and uptake by Caco-2 cells. J Agric Food Chem. 2007 Jul 25;55(15):6032-8.
Reed JD, Krueger CG, Vestling MM. MALDI-TOF mass spectrometry of oligomeric food polyphenols. Phytochemistry. 2005 Sep;66(18):2248-63.
Afaq F, Saleem M, Krueger CG, Reed JD, Mukhtar H. Anthocyanin- and hydrolyzable tannin-rich pomegranate fruit extract modulates MAPK and NF-kappaB pathways and inhibits skin tumorigenesis in CD-1 mice. Int J Cancer. 2005 Jan 20;113(3):423-33.
Krueger CG, Vestling MM, Reed JD. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of heteropolyflavan-3-ols and glucosylated heteropolyflavans in sorghum [Sorghum bicolor (L.) Moench]. J Agric Food Chem. 2003 Jan 29;51(3):538-43.