Effects of Phenolic‐Enriched Raspberry Extracts and Raspberry Ketone (4‐(4‐ hydroxyphenyl)‐2‐butanone) on Obesity Prevention in a Mouse Model of Diet‐Induced Obesity

Introduction Red raspberries ( Rubus idaeus ) contain numerous phenolic compounds with documented positive health benefits. One naturally occurring phenolic, raspberry ketone (4‐(4‐ hydroxyphenyl)‐2‐butanone), is considered the principle flavor component of red raspberries. Raspberry ketone, either as a sole or mixed ingredient, has been marketed as a weight loss supplement. Objective To investigate the metabolic signature associated with the weight preventative actions of a phenolic‐enriched raspberry extract compared with raspberry ketone in a diet‐induced obese mouse model. Methods Male C57BL/6 mice (8 wk old) received a daily oral dose of vehicle (Veh; 50% propylene glycol, 40% water, and 10% DMSO), raspberry extract low (REL; 0.2g/kg), raspberry extract high (REH; 2g/kg) or raspberry ketone (RK; 0.2g/kg). Coincident with daily dosing mice were placed on a high fat diet (45% Fat kcal) for 4 wks. Feeding, hormonal, and metabolic endpoints were assessed. Results For body weight gain, there was treatment effect [F (3, 59) = 5.7, p < 0.005] and treatment × time effect [F (81, 1593) = 5.5, p < 0.005]. On days 20–28, the RK had lower body weights (~9%) compared with Veh (p < 0.05 for all). On days 24–28, the REH had lower body weights (~7%) compared with the Veh (p < 0.05 for all). At the end of the 4 weeks, retroperitoneal [F (3, 55) = 4.8, p < 0.005], epidydimal [F (3, 55) = 10.6, p < 0.005], and inguinal [F (3, 55) = 6.8, p < 0.005] fat masses were lower (~25%) in the RK and REH compared with REL and Veh (p < 0.05 for all). There were no treatment differences in cumulative intake nor in meal patterns. Terminal plasma ghrelin levels [F (3, 57) = 3.5, p< 0.05] were lower (~44%) in REL, REH, and RK compared with Veh (p < 0.05), whereas corticosterone levels [F (3, 57) = 4.4, p <0.005] were elevated (~85%) in the REL compared with Veh (p < 0.05). Indirect calorimetry indicated the RER (VCO 2 /VO 2 ) [F (3, 28) = 7.4, p < 0.01] was lower (~5%) in REL, REH, REH compared with Veh (p < 0.005 for all). Mean blood pressure [F (3, 148) = 3.0, p < 0.05] was increased in the RK (~19%) and REH (~14%) compared with Veh (p < 0.05 for both). In addition, heart rate [F (3, 148) = 4.2, p < 0.05] was increased in the REH (~30%), REL (~34%), and RK (~38%) compared with Veh (p < 0.05 for all). Conclusion Raspberry ketone and phenolic‐enriched extracts of red raspberries have potential to prevent diet‐induced weight gain by alterations in metabolism. Support or Funding Information NIH R01 AT008933; USDA‐NIFA NJ06280 This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .