Dietary black raspberry anthocyanins do not alter development of obesity in mice fed an obesogenic high-fat diet

Anthocyanins (ACNs) from various foods have been shown to minimize the development of obesity in some animal models. The objective of the current study was to compare the effects of feeding purified black raspberry (BRB) ACNs or the freeze-dried whole BRB on the development of obesity. Male C57BL/6J mice (25 days of age) were assigned at random to treatments (7/treatment; 3/cage). The treatments included (1) control low-fat diet (10% calories from fat) (LF); (2) LF plus BRB juice in place of drinking water; (3) LF diet plus purified BRB ACNs in drinking water (1.25 mg/mL); (4) control high-fat diet (60% calories from fat) (HF60); (5) HF60 diet + BRB juice in place of drinking water; (6) HF60 diet + ACNs in drinking water (1.25 mg/mL); and (7) HF60 + freeze-dried whole BRB powder (21.7 g/kg of diet). Body weight gains in mice fed HF60 diet plus purified BRB ACNs tended to be lower after 56, 63, and 70 days than in mice fed HF60 alone. Body weights were increased at time of sacrifice, but heart, liver, and kidney weights as a percentage of body weight were decreased in mice fed HF60 diet compared to LF fed mice. Weights (g or g/body weight) of epididymal and retroperitoneal fat were increased in the HF60 fed mice compared to LF fed mice. Fasting serum glucose, leptin, and insulin levels as well as homeostasis assessment of insulin resistance (HOMA-IR) were elevated in mice fed the HF60 diet relative to LF-fed controls. Serum cholesterol, triglycerides, and monocyte chemoattractant protein-1 (MCP-1) were not altered by diet. Serum levels of resistin were increased in mice fed the HF60 diet compared to mice fed the LF diet. None of the responses measured were altered by whole BRB powder included in the diet relative to the HF60 control diet. Cyanidin containing di- or triglycosides in BRB was ineffective in altering the development of obesity in contrast to cyanidin-monoglycosides, which have been shown to be effective. The sugar moiety on the anthocyanidins may be an important factor in determining the response in the development of obesity.