title: Dietary broccoli mildly improves neuroinflammation in aged mice but does not reduce lipopolysaccharide-induced sickness behavior.
abstract: Aging is associated with oxidative stress and heightened inflammatory response to infection. Dietary interventions to reduce these changes are therefore desirable. Broccoli contains glucoraphanin, which is converted to sulforaphane (SFN) by plant myrosinase during cooking preparation or digestion. Sulforaphane increases antioxidant enzymes including NAD(P)H quinone oxidoreductase and heme oxygenase I and inhibits inflammatory cytokines. We hypothesized that dietary broccoli would support an antioxidant response in brain and periphery of aged mice and inhibit lipopolysaccharide (LPS)-induced inflammation and sickness. Young adult and aged mice were fed control or 10% broccoli diet for 28 days before an intraperitoneal LPS injection. Social interactions were assessed 2, 4, 8, and 24 hours after LPS, and mRNA was quantified in liver and brain at 24 hours. Dietary broccoli did not ameliorate LPS-induced decrease in social interactions in young or aged mice. Interleukin-1β (IL-1β) expression was unaffected by broccoli consumption but was induced by LPS in brain and liver of adult and aged mice. In addition, IL-1β was elevated in brain of aged mice without LPS. Broccoli consumption decreased age-elevated cytochrome b-245 β, an oxidative stress marker, and reduced glial activation markers in aged mice. Collectively, these data suggest that 10% broccoli diet provides a modest reduction in age-related oxidative stress and glial reactivity, but is insufficient to inhibit LPS-induced inflammation. Thus, it is likely that SFN would need to be provided in supplement form to control the inflammatory response to LPS.
authors.affiliation: Division of Nutritional Sciences, University of Illinois, 1201 West Gregory Dr, Urbana, IL 61801, USA.
authors.forename: Brigitte E
authors.initials: BE
authors.lastname: Townsend
authors.affiliation: Department of Food Science and Human Nutrition, University of Illinois, 1201 West Gregory Dr, Urbana, IL 61801, USA.
authors.forename: Yung-Ju
authors.initials: YJ
authors.lastname: Chen
authors.affiliation: Division of Nutritional Sciences, University of Illinois, 1201 West Gregory Dr, Urbana, IL 61801, USA; Department of Food Science and Human Nutrition, University of Illinois, 1201 West Gregory Dr, Urbana, IL 61801, USA.
authors.forename: Elizabeth H
authors.initials: EH
authors.lastname: Jeffery
authors.affiliation: Division of Nutritional Sciences, University of Illinois, 1201 West Gregory Dr, Urbana, IL 61801, USA; Integrative Immunology and Behavior Program, University of Illinois, 1201 West Gregory Dr, Urbana, IL 61801, USA; Department of Animal Sciences, University of Illinois, 1201 West Gregory Dr, Urbana, IL 61801, USA. Electronic address: rwjohn@illinois.edu.
authors.forename: Rodney W
authors.initials: RW
authors.lastname: Johnson
mesh_terms: D000375:Aging; D000818:Animals; D001522:Behavior, Animal; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D001937:Brassica / Q000737:chemistry*; D000073883:CX3C Chemokine Receptor 1; D005904:Glial Fibrillary Acidic Protein / Q000235:genetics / Q000378:metabolism; D055809:Illness Behavior; D053583:Interleukin-1beta / Q000378:metabolism; D008070:Lipopolysaccharides / Q000008:administration & dosage* / Q000009:adverse effects*; D008099:Liver / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D017628:Microglia / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D019707:Receptors, Chemokine / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D000073883:CX3C Chemokine Receptor 1; C471885:Cx3cr1 protein, mouse; D005904:Glial Fibrillary Acidic Protein; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D012333:RNA, Messenger; D019707:Receptors, Chemokine
keywords: Aging; BALB/c mice; Broccoli; Inflammation; LPS; Sulforaphane