Table 4.

Representative isoflavones, anthocyanins and their underlying anti-diabetic effects.

Flavonoid Subclass	Name of Flavonoid	Structure of Flavonoid	Dietary Source	Metabolites Produced from Flavonoids	Function of Flavonoids	Mechanism of Action	Model used		References
							In Vivo	In Vitro
Isoflavones	17. Genistein		Soybeans, kudzu, and fava bean		(A) Antihyperglycmeic effect: (B) Hypolipemic effect	Reduce hyperglycemia through the activity of cAMP/ PKA pathway Decrease Intercellular Adhesion Molecule 1 (ICAM-1) and p-ERK Inhibit the activity of tyrosine kinase Improve glucose intolerance and β-cells mass Decrease urinary excretion of TBARs	Streptozotocin (STZ)-induced diabetic rats Obese diabetic mice Nongenetictype 2 diabetic mice	INS-1 cells Human islet β-cells	[195,199]
	18. Daidzein		Soybeans, nuts, and soy milk	(A) Daidzin	(A) Antihyperglycmeic effect:	Decrease blood glucose, total cholesterol, and AMPK phosphorylation	Golden Syrian hamsters		[202,204]
Anthocyanins	19. Cyanidin		Bilberry, blueberry, grapes, blackberries, hawthorn, acai berry, and raspberry	(A) Anthocyanidin glucuronide conjugates (Major form in urine) (B) Simple Aglycones (Second major in urine) (C) Anthocyanidin methyl glucuronide conjugates (8 forms) (D) Cyanidin-3-glucoside E) Cyanidin-3-galactoside	(A) Antihyperglycmeic effect: (B) Hypolipemic effect:	Inhibit α-glucosidase and α-amylase which reduce the absorption of glucose in small intestine Reduce fasting glucose level Prevent pancreatic apoptosis Improve antioxidant status which protects hepatocytes from HG-induced damage Attenuate aortic lipid peroxidation	Streptozotocin (STZ)-induced diabetic rats db/db rats high fat diet fed mice	Mouse hepatocyte	[207,209]
	20.Delphinidin		Dark grapes, eggplant, berries, red cabbage, carrot, and tomato	(A) 4′-O- methyl delphinidin 3-O-beta-d- glucopyranoside	(A) Antihyperglycmeic effect:	Reduce the glycation rate of HbA1c Prevents diabetes associated injuries such as endothelial cell function	Diabetic mouse		[213,215]
	21.Pelargonidin		Bilberry and ficus bengalensis Linn	(A) Pelargonidin-O-glucuronide (B) Pelargonidin-3-galactoside	(A) Antihyperglycmeic effect: (B) Hypolipemic effect:	Reduce hyperglycemia Reduce the level of antioxidant defensive enzymes Stimulate insulin secretion Reduce the level of TBARS which is a byproduct of lipid peroxidation	Streptozotocin (STZ)-induced diabetic rats Diabetic rats		[217,219]