Liquorice flavonoid oil suppresses hyperglycaemia accompanied by skeletal muscle myocellular GLUT4 recruitment to the plasma membrane in KK-A^y mice

Abstract

For over 4000 years, liquorice has been one of the most frequently employed botanicals as a traditional herbal medicine. Although previous reports have found that liquorice flavonoids possess various health beneficial effects, the underlying mechanism responsible for the anti-diabetic effect of liquorice flavonoids remains unclear. The present study demonstrates that liquorice flavonoid oil (LFO) improves type 2 diabetes mellitus through GLUT4 translocation to the plasma membrane by activating both the adenosine monophosphate-activated protein kinase (AMPK) pathway and Akt pathway in muscle of KK-A^y mice. Furthermore, LFO lowered postprandial hyperglycaemia in a human study. These results indicate that LFO may exert a therapeutic effect on metabolic disorders, such as diabetes and hyperglycaemia, by modulating glucose metabolism through AMPK- and insulin-dependent pathways in skeletal muscle.

Graphical Abstract

Keywords:

• Glabridin
• flavonoid
• anti-hyperglycaemia
• GLUT4
• insulin

Acknowledgements

Author contributions: Y.Y.*, H.K., K.N. and H.A. conceived and designed the experiments; Y.Y.*, H.K., K.N. and Y.Y. performed the experiments; Y.Y.*, H.K., K.N. and Y.Y. analysed the data; H.K. and K.N. contributed reagents/materials/analysis tools; and Y.Y.* and H.A wrote the manuscript. Y.Y.*, Yoko YAMASHITA; Y.Y., Yasukiyo YOSHIOKA.

Disclosure statement

This work was partly supported by Kaneka Co. Ltd. The authors (HK and KN) are employees of Kaneka Corporation. This does not alter our adherence to all International Journal of Food Sciences and Nutrition policies on sharing data and materials, as detailed online in the guide for authors.