Soyasapogenols reduce cellular triglyceride levels in 3T3-L1 mouse adipocyte cells by accelerating triglyceride lipolysis

Soyasapogenol is a soyasaponin aglycone, which has been suggested to exert a more potent function than the glycoside form. In this study, the effect of soyasapogenol A and B on cultured adipocyte cell function was investigated using mouse 3T3-L1 adipocyte cells. 3T3-L1 cells were treated with insulin, dexamethasone, and 3-isobutyl-1-methylxanthine for differentiation to adipocytes, and the cells were then cultured in the presence of soyasapogenol A or B (6.25 or 12.5 µM). The media were harvested and refreshed every 2 d. After a 10 d culture, the cells were harvested and the triglyceride content of the cells was determined. The triglyceride content of soyasapogenol B-treated cells was significantly lower than those of vehicle-treated cells. Glycerol and free fatty acid levels in the soyasapogenol-treated cell media were higher than those in vehicle cells. However, there was no difference in the level of adipose triglyceride lipase among soyasapogenol A-, soyasapogenol B-, and vehicle-treated cells. The secreted adiponectin and resistin levels of soyasapogenol-treated cell media were also different compared with those of vehicle-treated cells. Especially, the secreted resistin level in soyasapogenol B-treated cell media was obviously reduced compared with that of vehicle-treated cells. Taken together, these results suggest that soyasapogenol B exerted an anti-obesity and anti-diabetic effect on adipocytes by lowering the cellular triglyceride level by accelerating triglyceride lipolysis with reduced resistin secretion. Keywords: Soyasapogenol A, Soyasapogenol B, 3T3-L1 adipocyte, Triglyceride, Lipolysis, Adipocytokin