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Blueberry supplementation lowers iNOS but not COX‐2 expression in LPS challenged rats
Author(s) -
GottschallPass Katherine,
Wark Michelle,
Yeung Horace,
Pass Eric,
Purcell Sarah,
MacPhee Robyn,
Sweeney Marva
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a367-a
Subject(s) - saline , inflammation , western blot , medicine , endocrinology , analysis of variance , chemistry , biochemistry , gene
Inflammation has been implicated in a number of chronic diseases including cardiovascular disease and aging. We examined whether supplementation with blueberry extracts would decrease LPS‐induced inflammation in vivo . Male Wistar rats (125–150 g) were fed control (AIN‐93G) or supplemented (0.02% post C18 blueberry extract) diet for 4 weeks. Feed intake was monitored daily and weight gain weekly. Animals (n=9) were subjected to LPS or saline injections (5 mg/kg i.p.); after 3 hours they were anesthetized with sodium pentobarbital (60 mg/kg) and blood was collected by cardiac puncture. Liver, lungs, brain and kidneys were collected, flash frozen in liquid nitrogen and stored at −80°C until analysis. One‐way ANOVA revealed no differences in feed intake (p=0.653), weight gain (p=0.563) or feed efficiency (p=0.868) among the three groups. Analysis of serum inflammatory markers by ELISA demonstrated a significant increase in TNFα (p=0.000) and IL‐1β (p=0.016) but not IL‐6 (p=0.241) in LPS treated animals when compared to saline treated controls. Supplementation with blueberries failed to significantly ameliorate these increases. Assessment of liver COX‐2 protein level by Western blot showed no differences among groups. Conversely, liver iNOS levels were increased with LPS treatment; blueberry supplementation reduced these levels to control. Analysis of COX‐2 and iNOS gene expression by real‐time PCR revealed no changes in COX‐2 among groups. Blueberry treatment failed to ameliorate the LPS‐induced increase in iNOS expression. Our results suggest that the anti‐inflammatory effects of blueberries may work through reduction in nitric oxide production by iNOS. Support by NSERC and AIF grants to KGP and MS.