Whole blueberry protects pancreatic beta-cells in diet-induced obese mouse

BackgroundBlueberry is rich in bioactive substances and possesses powerful antioxidant potential, which can protect against oxidant-induced and inflammatory cell damage and cytotoxicity. The aim of this study was to determine how blueberry affects glucose metabolism and pancreatic -cell proliferation in high fat diet (HFD)-induced obese mice.MethodsWild type male mice at age of 4weeks received two different kinds of diets: high-fat diet (HFD) containing 60% fat or modified HFD supplemented with 4% (wt:wt) freeze-dried whole blueberry powder (HFD+B) for 14weeks. A separate experiment was performed in mice fed with low-fat diet (LFD) containing 10% fat or modified LFD+B supplemented with 4% (wt:wt) freeze-dried whole blueberry powder. The metabolic parameters including blood glucose and insulin levels, glucose and insulin tolerances were measured.ResultsBlueberry-supplemented diet significantly increased insulin sensitivity and glucose tolerance in HFD+B mice compared to HFD mice. However, no difference was observed in blood glucose and insulin sensitivity between LFD+B and LFD mice. In addition, blueberry increased -cell survival and prevented HFD-induced -cell expansion. The most important finding was the observation of presence of small scattered islets in blueberry treated obese mice, which may reflect a potential role of blueberry in regenerating pancreatic -cells.ConclusionsBlueberry-supplemented diet can prevent obesity-induced insulin resistance by improving insulin sensitivity and protecting pancreatic -cells. Blueberry supplementation has the potential to protect and improve health conditions for both type 1 and type 2 diabetes patients.