Hypoglycemic Effects of Plant Flavonoids: A Review
Table 1
The summary of selected plant flavonoids.
Flavonoids
Structure
Mode of actions
Plants
Quercetin
(1) Inhibits the activity of glucose transporter [43] (2) Enhances glucose uptake through the activation of the AMPK signaling pathway in skeletal muscle cells [44, 45] (3) Reduces hepatic glucose production [46] (4) An inhibitory effect on α-glucosidase [47] (5) Protects against pancreatic islet beta-cell damage and assists in the regeneration of beta-cells [48]
Vaccinium vitis-idaea L. [44] Allium cepa L. [49] Allium fistulosum [50] Calamus scipionum [50] Camellia sinensis [50] Capsicum annum [50] Euonymus alatus [50]
Kaempferol
(1) Inhibitory effect on α-glucosidase [51] (2) Protects beta-cells against hyperglycemia-induced β-cell toxicity [52] (3) Improves the expressions of AMPK and GLUT4 [53]
(1) Antioxidant properties [55] (2) Inhibitory effect on α-glucosidases and α amylase [56] (3) Enhances glucose uptake in the muscle cells [57] (4) Improves the uptake of Ca2+ ions and affects insulin secretion [58]
Ruta graveolens [59] Morus alba [59] Amaranthus viridis [60]
Naringenin
(1) Enhances glucose uptake through the activation of AMPK signaling pathway in skeletal muscle cells [61, 62] (2) Protects the β-cells from apoptosis [63] (3) Enhances insulin receptor beta-subunit, GLUT4, and tissue insulin sensitivity [64] (4) Inhibitory effect on α-glucosidases [65] (5) Inhibits gluconeogenesis through the upregulation of AMPK [66]
Sambucus nigra L. [67] Madagascar periwinkle [68] Catharanthus roseus [68] Elaeodendron croceum [68]
Fisetin
(1) Attenuates carbohydrate metabolism enzymes [69] (2) Downregulates glycogenolysis and gluconeogenesis [70] (3) Reduces activity of glucose 6 phosphate dehydrogenase (G6PD) and glucose 6-phosphatase (G6Pase) [71] (4) Inhibits high glucose biomolecule-induced cytokine production [72]
