ABSTRACT
Benzyl isothiocyanate (BITC) is an organosulfur compound derived from cruciferous vegetables and papaya seeds. In this study, we investigated the effect of BITC on the lipid accumulation in 3T3-L1 preadipocytes during adipocyte differentiation. The treatment of BITC during the differentiation-inducing stage significantly ameliorated the lipid accumulation, whereas it had no inhibitory effect during the differentiation-maintaining stage. BITC also significantly suppressed the mRNA expression of the adipocyte-specific markers, such as CCAAT/enhancer-binding protein α (C/EBPα), C/EBPβ, C/EBPδ and peroxisome proliferator-activated receptor γ. BITC significantly inhibited the phosphorylation of extracellular signal-regulated kinase phosphorylation, whereas it enhanced that of AMP-activated protein kinase. Furthermore, BITC significantly suppressed the intracellular 2-deoxyglucose uptake as well as glucose transporter 4 expression. These results suggest that inhibition of the adipocyte differentiation and glucose uptake may mainly contribute to the inhibitory effect of BITC on the lipid accumulation in 3T3-L1 preadipocytes.
Abbreviations: PPARγ: peroxisome proliferator-activated receptor γ; CEBP: CCAAT/enhancer-binding protein; GLUT4: glucose transporter 4; AMPK: AMP-activated protein kinase; ERK1/2: extracellular signal-regulated kinase 1/2; MAPK: a mitogen-activated protein kinase; ITCs: isothiocyanates; BITC: benzyl isothiocyanate; FBS: fetal bovine serum; CS: calf serum; AITC: allyl ITC; IBMX: 3-isobutyl-1-methylxanthine; LDH: lactate dehydrogenase; KRH: Krebs-Ringer-Hepes-bicarbonate; 2-DG: 2-deoxy-d-glucose
The proposed mechanism for inhibition of the lipid accumulation in preadipocytes by BITC.
