The Effect of Soy Protein on Adipocyte Differentiation and Lipid Accumulation

Nutrition research is involved in combatting the obesity pandemic. Soy consumption is linked to a reduction in abdominal fat in rats. Currently, the bioactive soy protein subunit(s) and related molecular mechanism(s) associated with this effect remain unclear. This report examined the effect of soy glycinin and β-conglycinin on lipid accumulation and adipogenesis in rat adipose tissue and cultured mouse adipocytes. Mouse 3T3-L1 cells were differentiated in the presence of protein hydrolysates from Harovinton (conventional) and glycinin/β-conglycinin knockout strains. Sprague-Dawley rats (8 males, 8 females/group) were fed high-fat diets containing either 20% casein or 20% soy protein concentrates for 8 weeks. Harovinton increased lipid droplet size in 3T3-L1 cells (p<0.01) and increased mRNA (p<0.03) and protein levels (p<0.001) of peroxisome proliferator-activated receptor (PPARγ) in adipose tissue in female rats compared to casein control. This study showed that soy storage proteins may contribute to the maintenance of healthy white adipose tissue.