Serum, liver tissue, and cells biochemical analysis

Liver or adipose tissue was homogenized in 0.02 M phosphate buffered solution (pH 7.4). Each parameter in serum and liver was measured according to the protocols of respective kits. ALT, AST, Glucose, TGs, FFAs, and low density lipoprotein cholesterol (LDL-c) level in the serum, and glycerol in adipose tissue were measured using spectrophotometer kit, respectively. TGs content in the liver tissue and cells was measured using a TGs enzyme-test kit. Tumor necrosis factor-α (TNF-α), corticosterone (Cort), growth hormone (GH), adrenline (Adr), insulin, VLDL and 5-HT level in the serum, liver tissue, or the cultured primary rat hepatocytes and HepG2 cells was measured using ELISA kit, respectively. The Homeostasis Model of Assessment-IR (HOMA-IR) index, a marker of IR, was calculated as serum glucose × serum insulin / 22.5 ¹⁶.