ABSTRACT
This study determined if 18 days of supplementation with blueberries (BL) compared to placebo (PL) could mitigate muscle soreness and damage and improve inflammation resolution in untrained adults (n = 49, ages 18-50 years) after engaging in a 90-min bout of "weekend warrior" eccentric exercise. The BL freeze dried supplement provided 1 cup of fresh blueberries per day equivalent with 805 mg/day total phenolics and 280 mg/day anthocyanins. Urine levels of eight BL gut-derived phenolics increased after 14- and 18-days supplementation with 83% higher concentrations in BL vs. PL (p < 0.001). The 90-min exercise bout caused significant muscle soreness and damage during 4d of recovery and a decrease in exercise performance with no significant differences between PL and BL. Plasma oxylipins were identified (n = 76) and grouped by fatty acid substrates and enzyme systems. Linoleic acid (LA) oxylipins generated from cytochrome P450 (CYP) (9,10-, 12,13-dihydroxy-9Z-octadecenoic acids) (diHOMEs) were lower in BL vs. PL (treatment effect, p = 0.051). A compositive variable of 9 plasma hydroxydocosahexaenoic acids (HDoHEs) generated from docosahexaenoic acid (DHA, 22:6) and lipoxygenase (LOX) was significantly higher in BL vs. PL (treatment effect, p = 0.008). The composite variable of plasma 14-HDoHE, 17-HDoHE, and the eicosapentaenoic acid (EPA)-derived oxylipin 18-hydroxyeicosapentaenoic acid (18-HEPE) (specialized pro-resolving lipid mediators, SPM, intermediates) was significantly higher in BL vs PL (treatment effect, p = 0.014). Pearson correlations showed positive relationships between post-exercise DHA-LOX HDoHEs and SPM intermediates with urine blueberry gut-derived phenolics (r = 0.324, p = 0.023, and r = 0.349, p = 0.015, respectively). These data indicate that 18d intake of 1 cup/day blueberries compared to PL was linked to a reduction in pro-inflammatory diHOMES and sustained elevations in DHA- and EPA-derived anti-inflammatory oxylipins in response to a 90-min bout of unaccustomed exercise by untrained adults.
Subject(s)
Blueberry Plants , Oxylipins , Adult , Humans , Anthocyanins , Myalgia , Anti-Inflammatory Agents , Docosahexaenoic Acids , Eicosapentaenoic AcidABSTRACT
A hallmark of COVID-19 is a hyperinflammatory state associated with severity. Monocytes undergo metabolic reprogramming and produce inflammatory cytokines when stimulated with SARS-CoV-2. We hypothesized that binding by the viral spike protein mediates this effect, and that drugs which regulate immunometabolism could inhibit the inflammatory response. Monocytes stimulated with recombinant SARS-CoV-2 spike protein subunit 1 showed a dose-dependent increase in glycolytic metabolism associated with production of pro-inflammatory cytokines. This response was dependent on hypoxia-inducible factor-1α, as chetomin inhibited glycolysis and cytokine production. Inhibition of glycolytic metabolism by 2-deoxyglucose (2-DG) or glucose deprivation also inhibited the glycolytic response, and 2-DG strongly suppressed cytokine production. Glucose-deprived monocytes rescued cytokine production by upregulating oxidative phosphorylation, an effect which was not present in 2-DG-treated monocytes due to the known effect of 2-DG on suppressing mitochondrial metabolism. Finally, pre-treatment of monocytes with metformin strongly suppressed spike protein-mediated cytokine production and metabolic reprogramming. Likewise, metformin pre-treatment blocked cytokine induction by SARS-CoV-2 strain WA1/2020 in direct infection experiments. In summary, the SARS-CoV-2 spike protein induces a pro-inflammatory immunometabolic response in monocytes that can be suppressed by metformin, and metformin likewise suppresses inflammatory responses to live SARS-CoV-2. This has potential implications for the treatment of hyperinflammation during COVID-19.