Lipolysis Assay

Preadipocytes were induced to differentiate as previously described. At day 11 of differentiation, adipocytes were cultured in serum-free DMEM/F12 media and treated by GSPE for 12 h. Glycerol contents released in culture media were determined using a glycerol assay kit (Applygen, Beijing, China). Briefly, 50-µL medium was incubated at 37 °C for 10 min with 150 µL of reaction buffer, and the absorbance at 550 nm was read and calculated using a glycerol standard curve. Free fatty acid contents released in culture media were quantified by an FFA assay kit (Jiancheng, Nanjing, China), and the absorbance at 550 nm was read as described by the supplier.