Obesity is a risk factor for numerous metabolic disorders. In this study, we investigated the effects of the isothiocyanates sulforaphane (SA) and sulforaphene (SE) on adipogenesis in 3T3-L1 adipocytes. SE, a compound that is abundant in radish, inhibited adipogenesis by suppressing the adipogenic transcription factors peroxisome proliferator-activated receptor gamma (PPAR gamma, 69.2 +/- 2.4%, P < 0.05) and CCAAT/enhancer-binding protein alpha (C/EBP alpha, 36.1 +/- 3.1%, P < 0.05), thereby reducing fat accumulation in 3T3-L1 adipocytes (45.6 +/- 2.7%, P < 0.05); SA was less effective. SE exerted these activities through the activation of the Hedgehog (Hh) signaling pathway by restoring Smo ((2.1 +/- 0.2)-fold, P < 0.05) and Glil ((2.8 +/- 0.1)-fold, P < 0.05) expression, which was suppressed by adipogenic signals. These effects of SE were abrogated by treatment with the Hh inhibitor vismodegib. Thus, SE inhibits adipocyte differentiation via Hh signaling and may be an effective natural agent for preventing adipocyte hyperplasia and obesity.