Long-Term Dietary Strawberry, Spinach, or Vitamin E Supplementation Retards the Onset of Age-Related Neuronal Signal-Transduction and Cognitive Behavioral Deficits

173

133

Aging and age-related disorders such as Alzheimer's disease (AD) are usually accompanied by oxidative stress as one of the main mechanisms contributing to neurodegeneration and cognitive decline. Aging canines develop cognitive dysfunction and neuropathology similar to those seen in humans, and the use of antioxidants results in reductions in oxidative damage and in improvement in cognitive function in this canine model of human aging. In the present study, the effect of a longterm treatment with an antioxidant fortified diet and a program of behavioral enrichment on oxidative damage was studied in aged canines. To identify the neurobiological mechanisms underlying these treatment effects, the parietal cortex from 23 beagle dogs (8.1-12.4 years) were treated for 2.8 years in one of four treatment groups: i.e., control food-control behavioral enrichment (CC); control food -behavioral enrichment (CE); antioxidant food-control behavioral enrichment (CA); and enriched environment -antioxidant fortified food (EA). We analyzed the levels of the oxidative stress biomarkers, i.e., protein carbonyls, 3-nitrotyroine (3NT), and the lipid peroxidation product, 4- Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author ManuscriptNeurobiol Aging. Author manuscript; available in PMC 2009 January 1. Published in final edited form as:Neurobiol Aging. 2008 January ; 29(1): 51-70. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript hydroxynonenal (HNE), and observed a decrease in their levels on all treatments when compared to control, with the most significant effects found in the combined treatment, EA. Since EA treatment was most effective, we also carried out a comparative proteomics study to identify specific brain proteins that were differentially expressed and used a parallel redox proteomics approach to identify specific brain proteins that were less oxidized following EA. The specific protein carbonyl levels of glutamate dehydrogenase [NAD (P)], glyceraldehyde-3-phosphate dehydrogenase (GAPDH), α-enolase, neurofilament triplet L protein, glutathione S-transferase (GST) and fascin actin bundling protein were significantly reduced in brain of EA-treated dogs compared to control. We also observed significant increases in expression of Cu/Zn superoxide dismutase, fructose-bisphosphate aldolase C, creatine kinase, glutamate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase. The increased expression of these proteins and in particular Cu/Zn SOD correlated with improved cognitive function. In addition, there was a significant increas...

Section: Discussionmentioning

confidence: 97%

Section: Diet Treatmentmentioning

confidence: 99%

Proteomic identification of brain proteins in the canine model of human aging following a long-term treatment with antioxidants and a program of behavioral enrichment: Relevance to Alzheimer's disease

Opii

Joshi

Head

et al. 2008

173

133

“…The authors of this study relate the observed effects mainly to the rather unspecific antioxidant activity of catechin and other compounds contained in the preparation and fail to give further insights in the mechanisms related to the increase in mitochondrial SOD activity. Other investigators reported an attenuation of age-related decline in cognitive function and loss of behavioral deficits following long-term dietary supplementation with anthocyanidin-rich foods or plant extracts [90,91,216]. The investigators used several neuronal and behavioral parameters including dopamine-release, GTP-activity, calcium buffering in striatal synaptosomes, rod walking tasks and the water maze performance to elucidate possible mechanisms involved [90,91].…”

Section: Flavonoids: Neuroprotective Agents In Vivo and In Vitro?mentioning

confidence: 99%

MAPK signaling in neurodegeneration: influences of flavonoids and of nitric oxide

Schroeter

Boyd

Spencer

et al. 2002

302

176

Oxidative and nitrosative stress is increasingly associated with the pathology of neurodegeneration and aging. The molecular mechanisms underlying oxidative/nitrosative stress-induced neuronal damage are emerging and appear to involve a mode of death in which mitogen-activated protein kinase (MAPK) signaling pathways are strongly implicated. Thus, attention is turning towards the modulation of intracellular signaling as a therapeutic approach against neurodegeneration. Both endogenous and dietary agents have been suggested as potent modulators of intracellular signal transduction, e.g. nitric oxide and flavonoids, respectively. This review addresses recent findings on the biological effects of flavonoids and nitric oxide in neurodegeneration and aims to elucidate the rationale for their prospective use as modulators of cellular signal transduction. © 2002 Elsevier Science Inc. All rights reserved.Keywords: Apoptosis; Oxidative stress; Neuron; Flavonoids; MAP kinase; JNK; ERK; Epicatechin; Nitric oxide; Mitochondria; Redox status; Polyphenols Abbreviations: AKT, serine/threonine kinase (also known as protein kinase B); AP-1, activator protein-1; Apaf-1, apoptosis protease activating factor-1; ASK1, apoptosis signal-regulating kinase-1; Bad, Bcl-2/BclX Lassociated death promoting protein; Bax, pro-apoptotic protein of the Bcl-2 family; Bcl-2, B-cell lymphoma 2: protein with anti-apoptotic properties; BclX L , long form of Bclx: anti-apoptotic protein of the Bcl-2 family; Caspase, cysteinyl aspartic acid-protease; c-Jun, mammalian equivalent of Jun: part of the AP-1 transcription complex; CREB, cAMP response element binding protein; DIABLO/smac, mitochondria-related pro-apoptotic protein: inhibits XIAP; ERK1/2, extracellular signal-related kinase; Fas, CD95: member of the TNF receptor family; GSHST, glutathione Stransferase; JNK, c-Jun amino-terminal kinase; MAPK, mitogen-activated protein kinase; MAPKK, MAPK kinase; MAPKKK, MAPKK kinase; MEK1/2, ERK1/2-specific MAPKK; MKK4/7, JNK-specific MAPKK; MSK1, mitogen-and stress-activated kinase-1; NF-B, nuclear factor of immunoglobulin k locus in B-cells; ONOO − , peroxynitrite anion; p53, pro-apoptotic tumor suppressor gene product; PI3-kinase, phosphoinositol 3-kinase; Ras, small G-protein; RNS, reactive nitrogen species; ROS, reactive oxygen species; RSK, pp90 ribosomal S6 kinase; SAPK, stressactivated protein kinase; XIAP, X-linked inhibitor of apoptosis: inhibits the activation of caspase-9

“…Age-related declines of function have also been associated with higher levels of oxidative damage [10,23,44]. Various antioxidant treatments have been proposed in an attempt to retard deleterious changes associated with senescence [16,18,20,40].…”

Section: Introductionmentioning

confidence: 99%

Dietary melatonin selectively reverses age-related changes in cortical cytokine mRNA levels, and their responses to an inflammatory stimulus

Sharman

Yang

et al. 2002

The basal levels of expression of mRNA of cytokines, interleukin-6 (IL-6) and tumor necrosis factor (TNF-␣), in the cerebral cortex of 5 and 26 month-old male B6C3F1 mice have been compared. In addition, the responsivity of animals of differing age to an inflammatory stimulus (lipopolysaccharide, LPS) has been studied. Basal levels of both of these cytokine mRNAs were elevated in aged animals relative to the younger group. However LPS administration led to a robust increase in cytokine mRNA levels in the younger animals but in aged mice, there was either an unchanged (IL-6) or a depressed (TNF-␣) response. Administration of dietary melatonin (200 ppm) to aged mice for 6 weeks prior to sacrifice, resulted in reduction of basal levels of cytokine mRNA to values found in the younger animals. Furthermore, following administration of LPS to melatonin fed animals, cerebral cytokine mRNA levels were significantly elevated rather than being unchanged or depressed. Taken together these findings reflect a trend in the cortices of melatonin-treated aged mice, to more closely approximate the status of younger mice. For comparative purposes, parallel studies were carried out using an immunologically active organ (spleen) and a non-neural organ with a low rate of cell turnover (heart muscle). In both these tissues, basal levels of cytokine mRNAs of animals of either age were very low, and there was a marked positive response to LPS. Dietary melatonin had no effect on the responses of TNF-␣ mRNA to LPS but attenuated the reaction of splenic IL-6 mRNA, thus bringing the response closer to that of the younger mice.