Raspberry Ketone Reduced Lipid Accumulation in 3T3-L1 Cells and Ovariectomy-Induced Obesity in Wistar Rats by Regulating Autophagy Mechanisms

This study aimed to determine the antiobesity effects of raspberry ketone (RK), one of the major aromatic compounds contained in raspberry, and its underlying mechanisms. During adipogenesis of 3T3-L1 cells, RK (300 mu M) significantly reduced lipid accumulation and downregulated the expression of CCAAT/enhancer-binding protein alpha (C/EBP alpha), peroxisome proliferation-activated receptor gamma (PPAR gamma), fatty acid-binding protein 4 (FABP4), and fatty acid synthase (FAS). RK also reduced the expression of light chain 3B (LC3B), autophagy-related protein 12 (Atg12), sirtuin 1 (SIRT1), and phosphorylated-tuberous sclerosis complex 2 (TSC2), whereas it increased the level of p62 and phosphorylated-mammalian target of rapamycin (mTOR). Daily administration of RK decreased the body weight (ovariectomy [Ovx] + RK, 352.6 +/- 5 vs Ovx, 386 +/- 5.8 g; P < 0:05), fat mass (Ovx + RK, 3.2 +/- 0.05 vs Ovx, 5.0 +/- 0.4 g; P < 0.05), and fat cell size (Ovx + RK, 6.4 +/- 0.6 vs Ovx, 11.1 +/- 0.7 X 10(3) mu m(2); P < 0.05) in Ovx-induced obesity in rats. The expression of PPAR gamma, C/EBP alpha, FAS, and FABP4 was significantly reduced in the Ovx + RK group compared with that in the Ovx group. Similar patterns were observed in autophagy-related proteins and endoplasmic reticulum stress proteins. These results suggest that RK inhibited lipid accumulation by regulating autophagy in 3T3-L1 cells and Ovx-induced obese rats.