Targeting intestinal digestive enzymes by natural products: synergistic effect of flavonoids

Diabetes is a common metabolic disorder that is caused by either inherited and/or acquired deficiency in insulin secretion or due to decreased responsiveness to insulin. One of the common approaches in the treatment of diabetes is decreasing postprandial hyperglycemia by inhibiting key enzymes for the hydrolysis of carbohydrates in the small intestine. In our laboratories, the effects of various natural products on key digestive enzymes, α-glucosidase and α -amylase, are routinely assessed [1]. It was found that some flavonoids including kaempferol-3-O-rutinoside (KR, Fig.1) are potent inhibitors of these enzymes. A synergistic enzyme inhibitory effect; e.g, between KR and flavonoid aglycones, was observed for some flavonoids. The structure activity relationship established from the study and potential therapeutic implications are discussed.

Figure 1: KR StructureStructure of exemplary flavonoid glycoside with potent a-glucosidase inhibitory activity.

Keywords: Diabetes, α-glucosidase, α -amylase, flavonoids, kaempferol-3-O-rutinoside

References: 1. Habtemariam S (2011) Nat Prod Commun 6:201–203.