Suppression of Murine Preadipocyte Differentiation and Reduction of Visceral Fat Accumulation by a Petasites japonicus Ethanol Extract in Mice Fed a High-Fat Diet

We investigated in this study the anti-obesity effect of an extract of <I>Petasites japonicus</I> (a culinary vegetable from Eastern Asia) on a murine adipocyte cell line (3T3-L1) and on diet-induced obesity-prone mice. An ethanol extract of <I>P. japonicus</I>. (PJET) suppressed 3T3-L1 preadipocyte differentiation; however, a hot water extract of <I>P. japonicus</I> (PJHW) exhibited no effect on cell differentiation. PJET significantly attenuated three adipogenetic transcription factors, peroxisome proliferator-activated receptor γ2, CCAAT/enhancer-binding protein and sterol regulatory element-binding protein 1C, at the mRNA level and suppressed the gene expression of fatty acid synthetase. An experiment with diet-induced obesity-prone C57BL/6J mice showed that PJET lowered the body weight gain and visceral fat tissue accumulation, and ameliorated the plasma cholesterol concentration. These findings suggest that <I>P. japonicus</I> might be an effective food against obesity.