Dietary blueberry before and/or after stressor exposure attenuates neuroinflammation, oxidative stress, and cognitive deficits in rats

Authors: CAHOON, DANIELLE - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; Fisher, Derek; ZHENG, TONG - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; RABIN, BERNARD - University Of Maryland; Shukitt-Hale, Barbara

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/31/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Blueberries (BB), rich in antioxidant and anti-inflammatory polyphenols, have been shown to reduce inflammation, oxidative stress (OS), and cognitive deficits when administered before pathogenic stressors such as ionizing radiation (IR). However, little is known about the therapeutic value of BBs consumed after inflammatory and OS-inducing stressors. The objective of this research was to evaluate the differential effects of a BB-supplemented diet fed pre- and/or post-stressor on neuro-inflammation, OS, and cognitive deficits using IR (56Fe) as a model stressor. Male Sprague-Dawley rats (n=120, 5/group) were fed a 2% BB-supplemented diet for 45 days before and/or after receiving 0cGy or 150cGy of 56Fe radiation, in one of four diet conditions (no BB, pre-rad BB, post-rad BB, pre-/post-rad BB). Following radiation, the novel object recognition (NOR) test was performed to assess recognition memory. Protein levels of biomarkers for inflammation (e.g., inducible nitric oxide synthase [iNOS], cyclooxygenase-2 [COX-2]) and OS (e.g., NADPH oxidase [NOX2]) were assessed in the hippocampus and frontal cortex using Western blot. Results showed that percent time with the novel object was greater than 50% for all groups except irradiated rats on the control diet (p < 0.05), indicating that all BB treatment periods (pre-, post- and pre-/post-BB) significantly attenuated IR-induced deficits in recognition memory, with no differences between BB groups (p < 0.05). HZE particle irradiation increased neuroinflammation, OS, and glial activation in the frontal cortex and hippocampus and all dietary BB treatments attenuated these increases (p < 0.05). Changes in neuroinflammation, OS, and glial activation were positively correlated with each other and negatively correlated with recognition memory function. Overall, our findings support the use of dietary post-treatments to reduce the risk of neurodegeneration following neuroinflammatory/OS-inducing stressors, such as HZE particle irradiation, and potentially other unpredictable insults involving neuro-inflammation and OS such as stroke and traumatic brain injury.