Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2006-4-25
pubmed:abstractText
The mechanisms by which foods, such as fruit, are able to reduce the risk of chronic disease are still unclear. Several fruit products, including apples and apple juice, that are flavonoid-rich are reported to increase antioxidant levels in human subjects. This is supported by the finding from our previous studies that the chronic consumption of apple juice by human subjects reduced ex vivo low-density lipoprotein (LDL) oxidation; we hypothesized that this was due to the flavonoid in the apple juice, which, as we reported earlier, reduced in vitro LDL oxidation. To further explore whether the mixture of flavonoids and other phytochemicals in apples are biologically relevant antioxidants, we tested the effects of this flavonoid-rich apple extract (AE) on oxidant-related pathways in a model of the endothelium: human umbilical vascular endothelial cells (HU-VECs). The effects of AE on oxidant-responsive (i.e., tumor necrosis factor [TNF]-alpha-induced) nuclear factor (NF)- kappaB signaling in cell culture were assessed in transfected HUVECs by using a construct that expressed luciferase under the control of NF-kappaB. Incubation of HUVEC for 24 hrs with up to 10 mM (as gallic acid equivalents) of AE demonstrated no cytotoxicity, as determined by lactate dehydrogenase release, caspase 3 activation, and apoptosis marker-based FACS analysis. AE after a 24-hr incubation period at either 200 or 2000 nM showed a complex pattern of decreased basal and TNF-alpha-stimulated NF-kappaB signaling (63% maximal decrease) as assessed by luciferase activity in the transfected HUVECs, as well as by reduced levels of IkappaBalpha protein phosphorylation detected by Western blot analysis. We suggest that AE downregulates NF-kappaB signaling and that this is indicative of an antioxidant effect of the flavonoids present in AE.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1535-3702
pubmed:author
pubmed:issnType
Print
pubmed:volume
231
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
594-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Effect of apple extracts on NF-kappaB activation in human umbilical vein endothelial cells.
pubmed:affiliation
Department of Nutrition, University of California at Davis, 451 East Health Sciences Drive, Suite 6510, Davis, CA 95616, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't