Alcohol-free fermented blueberry-blackberry beverage phenolic extract attenuates diet-induced obesity and blood glucose in C57BL/6J mice

The aim of this study was to determine the potential of phenolic compounds from a fermented blackberry-blueberry beverage to reduce diet-induced obesity and hyperglycemia in mice fed a 60% high-fat diet (HFD) for 10 weeks after 1 week of pretreatment. C57BL/6J mice were randomized into six groups and allowed to drink (ad libitum) an alcohol-free blackberry-blueberry beverage [alcohol-free fermented beverage (AFFB), 8.4 mg anthocyanin (ANC)/kg body weight (BW)/day]; three doses of a phenolic extract [postamberlite extract (PAE)] from AFFB at 0.1 ×, 1 × and 2 × ANC concentrations; sitagliptin (hypoglycemic positive control); or water (negative control). Weight and fat mass gain were attenuated in mice receiving the highest doses of PAE (18.9 mg ANC/kg BW/day, P < .05). There were also reductions (P < .05) in percent fat mass, epididymal fat pad weights, mean adipocyte diameters and plasma triglycerides and cholesterol associated with PAE treatments. By the end of the study, fasting blood glucose for mice receiving 9 mg (1 ×) or 18.9 mg (2 ×) ANC/kg BW/day was significantly lower than in the water and the sitagliptin groups (P < .05). Histological and histochemical analyses revealed an unexpected change in liver of mice fed ANC at 1 × or 2 × doses consisting of liver enlargement and increased lipid deposition. PAE also induced the most differential gene expression changes, including highly significant downstream effects at all doses to reduce d-glucose concentrations. Overall, phenolic compounds from the fermented blueberry-blackberry beverage had an impact to attenuate the development of obesity and fasting blood glucose in C57BL/6J mice.