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

Abstract

IntroductionRed 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.ObjectiveTo 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.MethodsMale 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.ResultsFor 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 (VCO2/VO2) [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).ConclusionRaspberry ketone and phenolic‐enriched extracts of red raspberries have potential to prevent diet‐induced weight gain by alterations in metabolism.Support or Funding InformationNIH R01 AT008933; USDA‐NIFA NJ06280This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.