Serum insulin is lowered by rosehips in Sprague Dawley rats

Type 2 diabetes (T2D) is associated with increased oxidative stress and inflammation, Which impair insulin and glucose metabolism. Fruit and vegetables high in antioxidant compounds improve glucose and insulin metabolism in T2D. Rosehips contain significant levels of antioxidant and anti-inflammatory compounds. The objective of this study was to determine if rosehips could positively influence glucose and insulin metabolism. Mate Sprague-Dawley rats were fed either AIN-93 diet or AIN-93G diet + 10% ground rosehips for two weeks. The diets were isonitrogenous and isocaloric; the animals were pair-fed and meal trained to provide tight metabolic control. There was no significant difference in weight gain, serum triglycerides, glucose or total cholesterol between groups. However, the rosehip group had significantly lower (p<0.05) serum insulin levels (4.3 +/- 0.5 ng/ml), compared to control group (6.6 +/- 0.7 ng/ml). DNA microarray analysis showed that genes associated with fatty acid metabolism were upregulated, while genes associated with insulin and glucose metabolism were down regulated in the rosehip fed animals compared to the control animals. This study shows that rosehips are able to lower insulin secretion.