Metabolic effects of dietary Saskatoon berry powder in experimental mouse models

In this study the metabolic effects of dietary Saskatoon berry powder (SBP) have been tested in a diabetic mouse model, namely db/db mice as well as their wild-type counterparts, C57BL/6J mice. Saskatoon berries were purchased locally and SBP was prepared using standard freeze-dry methods. Both animal models were purchased from the Jackson Laboratories, USA. SBP was added to the mouse chow at 5% (w/w). The animals were fed with the experimental diets for 4 weeks. Body weight, food intake, plasma lipid levels as well as blood glucose levels were measured. At sacrifice, final blood samples and urine were taken and used for final biochemical analyses. The hearts, livers and pancreas were collected and processed for histological and immunohistological examinations. The db/db mice had larger body weight and food consumption throughout the study as compared to those in the wild-type mice. Furthermore, the db/db mice developed a state of
hypercholesterolemia and hyperglycemia by the end of the study as compared to the wild-type mice. Regular consumption of SBP was associated with an approximate 30% reduction in blood and urine glucose levels in db/db mice only. Reductions in blood glucose and urine levels were associated with apparent increases in beta-cell population in the islands of Langerhans as observed by immunohistological examinations. Morphological examinations of the liver and
kidney tissues revealed fewer tissue destructions in the SBP-treated db/db mice as compared to those in the non-treated control db/db animals. This short-term study suggests beneficial metabolic effects for SBP in these animal models. Future studies warrant long-term safety and efficacy of SBP in other animal models of type-2 diabetes and patients with mild to moderate hyperglycemia. (This study was approved by the Animal Care Committee at the University of Manitoba. Financial support from Agricultural and Food Development
Initiative- Growing Forward 2, Diabetes Canada and Natural Sciences,
and Engineering Research Council of Canada (NSERC) is appreciated.
The authors would like to thank the St. Boniface Hospital Research
Foundation for providing the infrastructure that enabled this study.)