TCF7L2-rs7903146 polymorphism modulates the effect of artichoke leaf extract supplementation on insulin resistance in metabolic syndrome: a randomized, double-blind, placebo-controlled trial

J Integr Med. 2018 Sep;16(5):329-334. doi: 10.1016/j.joim.2018.05.006. Epub 2018 Jun 1.


Background: Transcription factor 7-like 2 (TCF7L2)-rs7903146 polymorphism is associated with increased risk of type 2 diabetes. The response of insulin and insulin resistance to artichoke leaf extract (ALE) may be affected by TCF7L2-rs7903146 polymorphism.

Objective: This study examined the effects of ALE supplementation on metabolic parameters of the TCF7L2-rs7903146 polymorphism in patients with metabolic syndrome (MetS).

Design, setting, participants and interventions: This double-blind clinical trial was conducted on 80 patients with MetS in Sina Clinic, Khoy, Iran. The patients were randomized into ALE or placebo groups to receive either ALE (1800 mg/d as four tablets) or matching placebo for 12 weeks.

Main outcome measures: Anthropometric indices, blood pressure, glucose and lipid profile levels were measured before and after the study. Moreover, patients were genotyped for TCF7L2 polymorphism.

Results: ALE supplementation decreased insulin level and the homeostasis model assessment of insulin resistance (HOMA-IR) in patients with the TT genotype of TCF7L2-rs7903146 polymorphism (P < 0.05). There was no significant interaction between blood pressure, glucose and lipid profile response to ALE supplementation.

Conclusion: The responses of insulin and HOMA-IR to ALE supplementation have shown an interaction with single-nucleotide polymorphism rs7903146 in TCF7L2.

Trial registration: Iranian Registry of Clinical Trial IRCT201409033320N9.

Keywords: Alternative and complementary medicine; Artichoke leaf extract; Diabetes; Insulin; Insulin resistance; Metabolic syndrome; Transcription factor 7-like 2.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Blood Glucose / metabolism
  • Cynara scolymus*
  • Dietary Supplements
  • Double-Blind Method
  • Female
  • Genotype
  • Humans
  • Insulin / blood
  • Insulin Resistance / genetics*
  • Male
  • Metabolic Syndrome / blood
  • Metabolic Syndrome / drug therapy*
  • Metabolic Syndrome / genetics
  • Middle Aged
  • Phytotherapy*
  • Plant Extracts / pharmacology*
  • Polymorphism, Single Nucleotide*
  • Transcription Factor 7-Like 2 Protein / genetics*


  • Blood Glucose
  • Insulin
  • Plant Extracts
  • Transcription Factor 7-Like 2 Protein