Blueberry polyphenol-enriched soybean flour reduces hyperglycemia, body weight gain and serum cholesterol in mice

Abstract

Defatted soybean flour (DSF) can sorb and concentrate blueberry anthocyanins and other polyphenols, but not sugars. In this study blueberry polyphenol-enriched DSF (BB-DSF) or DSF were incorporated into very high fat diet (VHFD) formulations and provided ad libitum to obese and hyperglycemic C57BL/6 mice for 13 weeks to investigate anti-diabetic effects. Compared to the VHFD containing DSF, the diet supplemented with BB-DSF reduced weight gain by 5.6%, improved glucose tolerance, and lowered fasting blood glucose levels in mice within 7 weeks of intervention. Serum cholesterol of mice consuming the BB-DSF-supplemented diet was 13.2% lower than mice on the diet containing DSF. Compounds were eluted from DSF and BB-DSF for in vitro assays of glucose production and uptake. Compared to untreated control, doses of BB-DSF eluate containing 0.05 – 10 μg/μL of blueberry anthocyanins significantly reduced glucose production by 24% - 74% in H4IIE rat hepatocytes, but did not increase glucose uptake in L6 myotubes. The results indicate that delivery of blueberry polyphenols stabilized in a high-protein food matrix may be useful for the dietary management of pre-diabetes and/or diabetes.

Effects of a high fat meal matrix and protein complexation on the bioaccessibility of blueberry anthocyanins using the TNO gastrointestinal model (TIM-1)

“…Protein-rich flours, such as defatted soy flour (DSF), can preferentially sorb mid-polarity range anthocyanins and other polyphenols from fruit juices, whilst polar sugars remain in the juice supernatant, yielding a stable and biologically active polyphenol-enriched DSF food ingredient (Roopchand, Grace et al, 2012; Roopchand, Kuhn et al, 2012). Compared to DSF alone, blueberry polyphenol-enriched DSF was shown to significantly reduce hyperglycemia, body weight gain and serum cholesterol in C57BL/6J mice (Roopchand, Kuhn, Rojo, Lila, & Raskin, 2013; Roopchand, Grace et al, 2012). …”

Reuse potential of artichoke (Cynara scolimus L.) waste for the recovery of phenolic compounds and bioenergy

“…This has led to campaigns for promoting the consumption of fruit and vegetables as well as to the idea of enriching common foods with phenolic compounds (Sun-Waterhouse, 2013). Polyphenolenriched soybean flour (Roopchand et al, 2013) and fruit smoothies fortified with olive leaf extracts containing oleuropein and hydroxytyrosol (Kranz et al, 2010) are two examples of the products that have been proposed for this type of applications.…”

Blueberry extract inhibits carbohydrate-hydrolyzing enzymes and these inhibitory activities are not proanthocyanidin dependent

“…In addition, an animal trial using low-bush blueberries demonstrated that the phenolic-enriched fraction can enhance insulin sensitivity (Grace et al 2009), which in turn can help manage Type 2 diabetes. A recent animal trial using obese and hyperglycemic C57BL/6 mice showed that administration of defatted soybean flour fortified with blueberry phenolics for 13 weeks reduces weight gain, improves glucose tolerance, and lowers fasting blood glucose levels (Roopchard et al 2012). Another preliminary study showed that both high-bush and low-bush blueberries have a phenolic-dependent alpha-glucosidase inhibitory activity (Wang et al 2012).…”