Isoflavones in Chickpeas Inhibit Adipocyte Differentiation and Prevent Insulin Resistance in 3T3-L1 Cells

Diabetes mellitus is a metabolic disease characterized by hyperglycemia arising from defects in insulin secretion. This study investigated the effects of isoflavones in chickpea sprouts germinated in light (IGL) and isoflavones in chickpea seeds (ICS) on insulin resistance through their role in suppression of 3T3-L1 adipocyte differentiation. Results showed that IGL and ICS inhibit the differentiation of 3T3-L1 pre-adipocytes induced by differentiation medium in a dose-dependent manner, and the suppressive effect of IGL was stronger (p < 0.05) than that of ICS, evidenced by a decrease of Oil Red 0 staining and intracellular triacylglycerol content in the mature adipocytes. IGL and ICS also stimulated glucose uptake significantly (p < 0.05). Besides, IGL and ICS treatment caused a significant decrease in mRNA and protein expression levels of adipogenesis-related transcription factors peroxisome proliferator-activated receptor gamma (PPAR gamma) and CCAAT-enhancer-binding protein alpha (C/EBP alpha). Furthermore, the mRNA and protein expression levels of adipocyte fatty acid-binding protein (ap2), lipoprotein lipase (LPL), uncoupling protein-2 (UCP-2), and glucose transporter 4 (Glut4) in 3T3-L1 cells were also markedly down-regulated (p < 0.05).