Isolation and Characterization of Polyphenol Type-A Polymers from Cinnamon with Insulin-like Biological Activity

TLDR

Dietary factors are implicated in the regulation and prevention of type 2 diabetes, though its causes and control remain unclear. The study aimed to isolate and characterize cinnamon‑derived complexes that enhance insulin activity to potentially alleviate or prevent glucose intolerance and diabetes. The authors isolated A‑type procyanidin oligomers from cinnamon, comprising monomeric units of 288 Da, trimers of 864 Da, and a tetramer of 1152 Da. These polymers increased insulin‑dependent glucose metabolism by roughly 20‑fold, displayed antioxidant activity, and may help control glucose intolerance and diabetes. Keywords: glucose, insulin, diabetes, cinnamon, polyphenols, spice.

Abstract

The causes and control of type 2 diabetes mellitus are not clear, but there is strong evidence that dietary factors are involved in its regulation and prevention. We have shown that extracts from cinnamon enhance the activity of insulin. The objective of this study was to isolate and characterize insulin-enhancing complexes from cinnamon that may be involved in the alleviation or possible prevention and control of glucose intolerance and diabetes. Water-soluble polyphenol polymers from cinnamon that increase insulin-dependent in vitro glucose metabolism roughly 20-fold and display antioxidant activity were isolated and characterized by nuclear magnetic resonance and mass spectroscopy. The polymers were composed of monomeric units with a molecular mass of 288. Two trimers with a molecular mass of 864 and a tetramer with a mass of 1152 were isolated. Their protonated molecular masses indicated that they are A type doubly linked procyanidin oligomers of the catechins and/or epicatechins. These polyphenolic polymers found in cinnamon may function as antioxidants, potentiate insulin action, and may be beneficial in the control of glucose intolerance and diabetes. Keywords: Glucose; insulin; diabetes; cinnamon; polyphenols; spice