Antihyperglycemic effect of equol, a daidzein derivative, in cultured L6 myocytes and ob/ob mice
Article first published online: 3 SEP 2013
© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Molecular Nutrition & Food Research
Volume 58, Issue 2, pages 267–277, February 2014
How to Cite
Cheong, S. H., Furuhashi, K., Ito, K., Nagaoka, M., Yonezawa, T., Miura, Y. and Yagasaki, K. (2014), Antihyperglycemic effect of equol, a daidzein derivative, in cultured L6 myocytes and ob/ob mice. Mol. Nutr. Food Res., 58: 267–277. doi: 10.1002/mnfr.201300272
- Issue published online: 3 FEB 2014
- Article first published online: 3 SEP 2013
- Manuscript Accepted: 4 JUL 2013
- Manuscript Revised: 17 JUN 2013
- Manuscript Received: 15 APR 2013
- Japan Society for the Promotion of Science (JSPS)
- Takano Life Science Research Foundation, Ibaragi, Japan
- Glucose transporter 4;
- Glucose uptake;
- L6 myocytes
Molecular mechanisms for the potential antihyperglycemic effect of equol remain to be elucidated. In this study, we investigated the in vitro effect of equol on glucose uptake, AMP-activated protein kinase (AMPK) phosphorylation, and glucose transporter 4 (GLUT4) translocation to plasma membrane in L6 myocytes, and its in vivo antihyperglycemic effect in obese-diabetic model ob/ob mice.
Methods and results
Equol was found to promote glucose uptake, AMPK phosphorylation, and GLUT4 translocation detected by Western blotting analyses in L6 myotubes under a condition of insulin absence. Equol (0.05% in diet) suppressed the rise in serum glucose, cholesterol, triglyceride, and lipid peroxide concentrations and the hepatic triglyceride level as compared with those in the control group. Moreover, equol treatment suppressed the rises in fasting blood glucose level and improved the impaired glucose tolerance in ob/ob mice. Furthermore, equol treatment was demonstrated to improve expression of hepatic gluconeogenesis- and lipogenesis-related genes in terms of glucose and lipid metabolism.
The hypoglycemic effect of equol is related to increased GLUT4 translocation to the plasma membrane via AMPK activation. In addition, equol suppresses the fasting blood glucose level and gene expression of hepatic enzymes related to glucose metabolism. These results strongly suggest that equol has antidiabetic potential.