The analysis of fagopyritols from tartary buckwheat and their anti-diabetic effects in KK-Ay type 2 diabetic mice and HepG2 cells

Abstract

The studies of fagopyritols in tartary buckwheat and their anti-diabetic effects are limited. The fagopyritol B1 was the major fagopyritol in tartary buckwheat. The content of fagopyritols was 11-fold of free D-chiro-inositol (DCI) in tartary buckwheat. In KK-Ay mice, administration of fagopyritol B1 for 6-week was more effective in suppressing progressive rise of blood glucose, improving impaired glucose tolerance, and increasing insulin sensitivity than DCI and fagopyritol A1. Besides, both of fagopyritols and DCI improved the lipid homeostasis. Fagopyritols increased the expression of insulin receptor and PI3K in liver and skeletal muscle, as the same as DCI. According to the in vitro study, fagopyritols and DCI increased glucose consumption in both normal and insulin resistant HepG2 cells. In addition, fagopyritols and DCI upregulated phosphorylation of PI3K and AKT. In summary, these findings suggested that fagopyritols and DCI have potential anti-diabetic effects via activation of the insulin dependent pathway of PI3K/AKT.

Keywords

• Fagopyritols
• Tartary buckwheat
• Glucose and lipid metabolism
• Insulin sensitivity
• Insulin signaling