Are cinnamon derivatives effective and safe for diabetes?

Background/aim: Cinnamon spice is obtained by drying the tree bark of Cinnamomum Schaeff. species. The genus Cinnamomum belongs to the family Lauraceae, which comprises approximately 250 different species worldwide. The most common species on the market are Cinnamomum verum J. S. Presl, C. cassia (L.) J. Presl, C. burmannii (Nees & T. Nees) Blume, and C. loureiroi Nees. Cinnamon and its byproducts have been used for many years due to their antidiabetic effect. In the current study, the major chemical content and in vitro antidiabetic activities of different commercially available cinnamon samples were evaluated to determine whether they are safe to use for health purposes.

Materials and methods: Macroscopic analyses, chromatographic analyses, and enzyme inhibition assays on diabetes-related enzymes (α-amylase, α-glucosidase, and aldose reductase) were performed on seven different samples (cinnamon sticks, tea bags, and capsules).

Results: The cinnamon samples inhibited diabetes-related enzymes. The aqueous and ethanolic extracts of different cinnamon species demonstrated 7.73-333.69 mg/g of trans-cinnamaldehyde, and up to 43.73 mg/g of coumarin. Decoction and ethanolic extracts of C. cassia, C. burmannii, and C. loureiroi cinnamon sticks were detected to contain high levels of coumarin, which could pose a health risk, according to European Food Safety Authority data. Although antidiabetic activity was observed in the ready-made samples purchased from a herbalist, trans-cinnamaldehyde or coumarin compounds were not detected in the high-performance liquid chromatography analysis.

Conclusion: The source of the cinnamon spice is crucial for the utilization of cinnamon both in food and therapeutic purposes. This research once again showed the importance of meticulous inspection of the products sold by herbalists.