title: [Effect of Trigonella foenum-graecum 4-hydroxyisoleucine on high-glucose induced insulin resistance in 3T3-L1 adipocytes of mice].
abstract: OBJECTIVE
  To investigate the effect of 4-hydroxyisoleucine (4-HIL), an active component of Trigonella Foenum-graecum L. on high glucose induced insulin resistance (IR) in 3T3-L1 adipocytes, and to explore underlying molecular mechanisms.
  
  
  METHODS
  3T3-L1 adipocytes were treated with 25 mmol/L glucose and 0.6 nmol/L insulin to induce IR. They were intervened by different concentrations of 4-HIL (at 5, 10, and 20 micromol/L). [3H]-Deoxy-D-glucose up-taking method was used to detect the glucose uptake. The mRNA expression of cellular tumor necrosis factor-alpha (TNF-alpha) was detected by polymerase chain reaction (PCR). The content of TNF-alpha in the culture supernatant was detected by enzyme-linked immunosorbent assay (ELISA). Palmitic acid (PA) acted as the control.
  
  
  RESULTS
  After intervened by 25 mmol/L glucose and 0.6 nmol/L insulin for 18 h, the insulin-stimulated glucose transportation in 3T3-L1 adipocytes was inhibited by 63%. The mRNA expression of cellular TNF-alpha in adipocytes significantly increased, when compared with that in normal adipocytes (P < 0.05). The level of TNF-alpha secreted in the culture supernatant was increased by 70 pg/mL (P < 0.05). Similar changes occurred in the PA group. After exposure to 4-HIL (5, 10, or 20 micromol/L) for 24 h, the glucose transportation was increased by 35%, 50%, and 60%, respectively. PCR results showed that along with increasing 4-HIL concentrations, the mRNA expression of cellular TNF-alpha showed a decreasing trend, showing statistical difference when compared with the model group and the PA group (P < 0.05). Compared with the model group, the TNF-alpha level in the supernatant was respectively reduced by 10 pg/mL, 18 pg/mL, and 39 pg/mL after intervention (P < 0.05).
  
  
  CONCLUSIONS
  4-HIL could remarkably improve high glucose-induced IR in 3T3-L1 adipocytes. Meanwhile, 4-HIL could inhibit the secretion of TNF-alpha.
authors.affiliation: Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Respiration, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Wu
authors.affiliation: Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
authors.forename: Fu-Rong
authors.initials: FR
authors.lastname: Lu
authors.affiliation: Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Xie
authors.affiliation: Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
authors.forename: Na
authors.initials: N
authors.lastname: Zheng
authors.affiliation: Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
authors.forename: You
authors.initials: Y
authors.lastname: Qin
authors.affiliation: Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.affiliation: Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Du
authors.affiliation: Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
authors.forename: Liu-Meng
authors.initials: LM
authors.lastname: Jian
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D005947:Glucose / Q000009:adverse effects / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D007532:Isoleucine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D051379:Mice; D029910:Trigonella / Q000737:chemistry*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: C104672:4-hydroxyisoleucine; D007328:Insulin; D014409:Tumor Necrosis Factor-alpha; D007532:Isoleucine; D005947:Glucose