Glycyrrhizic acid increases glucagon like peptide-1 secretion via TGR5 activation in type 1-like diabetic rats

  • Biomed Pharmacother. 2017 Nov;95:599-604. doi: 10.1016/j.biopha.2017.08.087.
Lin-Yu Wang  1 ,  Kai Chun Cheng  2 ,  Yingxiao Li  3 ,  Chiang-Shan Niu  4 ,  Juei-Tang Cheng  5 ,  Ho-Shan Niu  6
Affiliations
  • 1. Department of Childhood Education and Nursery, Chia Nan University of Pharmacy and Science, Rende, Tainan City 71710, Taiwan; Division of Pediatrics, Chi-Mei Medical Center, Yong Kang, Tainan City 71003, Taiwan; Department of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City 81201, Taiwan.
  • 2. Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8520, Japan.
  • 3. Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8520, Japan; Department of Medical Research, Chi-Mei Medical Center, Yong Kang, Tainan City 71003, Taiwan.
  • 4. Department of Nursing, Tzu Chi University of Science and Technology, Hualien City 97005, Taiwan.
  • 5. Department of Medical Research, Chi-Mei Medical Center, Yong Kang, Tainan City 71003, Taiwan; Institute of Medical Science, College of Health Science, Chang Jung Christian University, Guei-Ren, Tainan City 71101, Taiwan. Electronic address: [email protected].
  • 6. Department of Nursing, Tzu Chi University of Science and Technology, Hualien City 97005, Taiwan. Electronic address: [email protected].
PMID: 28881290 DOI: 10.1016/j.biopha.2017.08.087
Abstract

Glycyrrhizic acid (GA) is belonged to triterpenoid saponin that is contained in the root of licorice and is known to affect metabolic regulation. Recently, glucagon like peptide-1 (GLP-1) has widely been applied in diabetes therapeutics. However, the role of GLP-1 in GA-induced anti-diabetic effects is still unknown. Therefore, we are interested in understanding the association of GLP-1 with GA-induced effects. In type 1-like diabetic rats induced by streptozotocin (STZ-treated rats), GA increased the level of plasma GLP-1, which was blocked by triamterene at a dose sufficient to inhibit Takeda G-protein-coupled receptor 5 (TGR5). The direct effect of GA on TGR5 has been identified using the cultured Chinese hamster ovary cells (CHO-K1 cells) transfected TGR5 gene. Moreover, in intestinal NCI-H716 cells that secreted GLP-1, GA promoted GLP-1 secretion with a marked elevation of calcium levels. However, both effects of GA were reduced by ablation of TGR5 with siRNA in NCI-H716 cells. Therefore, we demonstrated that GA can enhance GLP-1 secretion through TGR5 activation.

Keywords
GLP-1; Glycyrrhizic acid; Sitagliptin; TGR5; Triamterene.
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