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Polyphenolic-rich berry fruits are known to activate redox-sensitive cellular signaling molecules such as phosphatidylinositol-3-kinase (PI3 kinase)/kinase B (Akt), resulting in a cascade of downstream signaling pathways. This study investigated the ability of strawberry (SB), wild blueberry (WBB), and cranberry (CB) extracts to induce the activation of PI3 kinase/Akt signaling in vitro in human umbilical endothelial cells (HUVECs) and whether this activation would enhance cell migration and angiogenesis. Anthocyanin profiles of the extracts were characterized using HPLC-ESI/MS, and Akt activation was investigated using the Alpha Screen SureFire assay. The total anthocyanin contents of SB, WBB, and CB extracts were 81.7, 82.5, and 83.0 mg/100 g fresh weight, respectively. SB, WBB, and CB extracts activated Akt in a dose-dependent manner via PI3 kinase and induced cell migration and angiogenesis in vitro in HUVECs. The results from this study suggest that polyphenolics in berry fruits may play a role in promoting vascular health.

To investigate the effects of Strawberry antioxidants on oxidative stress-mediated impaired insulin signaling in in vitro in Human Skeletal Muscle Cells (HSkMC) • Strawberry antioxidants have a possible protective effect on oxidative stress-induced impaired insulin signaling as measured in vitro in HSkMC • Oxidative stress induced by H2 O2 increased the levels of Serine (307) phosphorylation of IRS-1 and decreased the levels of tyrsosine phosphorylations • Strawberry extract reversed the oxidative stress-induced increased levels of inhibitory phosphorylation (Ser 307) , and decreased levels of tyrosine phosphorylation of IRS-1 • Proposed mechanism of action to restore insulin signaling is through reduced cellular oxidative stress by Strawberry antioxidants Strawberry Extract Attenuates Oxidative Stress-Induced Impaired Insulin Signaling In vitro in Human Skeletal Muscle Cells.

1. Prior, R. L. et al. 2003. Assays for Hydrophilic and Lipophillic Antioxidant Capacity (oxygen radical absorbance capacity (ORAC (FL))) of Plasma and other Biological and Food Samples. J. Agric. Food Chem., 51:3273-3279 2. Benzie, I., F. et al. 1996. ''The Ferric Reducing Ability of Plasma (FRAP) as a Measure of “Antioxidant Power”: The FRAP Assay '' Analytical Biochemistry 239, pp 70-76. Acknowledgments

Objective: This investigation was undertaken to determine whether a grape seed extract (GSE) that is rich in mono-, oligo- and poly- meric polyphenols would modify postprandial oxidative stress and inflammation in individuals with the metabolic syndrome (MetS).Background: MetS is known to be associated with impaired glucose tolerance and poor glycemic control. Consumption of a meal high in readily available carbohydrates and fat causes postprandial increases in glycemia and lipidemia and markers of oxidative stress, inflammation and insulin resistance. Materials/methods: After an overnight fast, twelve subjects with MetS (5 men and 7 women) consumed a breakfast meal high in fat and carbohydrate in a cross-over design. A GSE (300 mg) or placebo capsule was administrated 1 hr before the meal (-1 hr). Changes in plasma insulin, glucose, oxidative stress and inflammatory markers were measured hourly for 6 hr. Results: Plasma hydrophilic oxygen radical absorbance capacity (ORAC) measured as the positive incremental area under the curve (-1 to 5 hr) was significantly increased when the meal was preceded by GSE compared with placebo (P0.05). No changes in inflammatory markers were evident. Conclusion: These data suggest that GSE enhances postprandial plasma antioxidant status and reduces the glycemic response to a meal, high in fat and carbohydrate in subjects with the MetS.