Determining the Effectiveness and Safety of Cinnamon Derivatives for Diabetes Treatment with HPLC

A joint study by Gazi University (Ankara, Turkey) and Düzce University (Düzce, Turkey) evaluated the major chemical content and in vitro antidiabetic activities of different commercially available cinnamon samples to determine whether they are safe to use for health-related reasons. A paper based on this study was published in the Turkish Journal of Medical Sciences (1). High performance liquid chromatographic (HPLC) and thin-layer chromatographic (TLC) analyses, macroscopic analyses, and enzyme inhibition assays on diabetes-related enzymes (α-amylase, α-glucosidase, and aldose reductase) were performed on seven different cinnamon samples (cinnamon sticks, tea bags, and capsules) in this analysis; cinnamon bark has been used in folk medicine to regulate blood sugar, and its effect on diabetes has been demonstrated in multiple studies (2-5).

Diabetes is a condition characterized by chronically high blood sugar, resulting from either inadequate insulin production or the body's resistance to insulin (6). According to statistical studies, the number of adults worldwide suffering from diabetes reached 537 million in 2021, with estimates of that number increasing to 643 million by 2030 and 783 million by 2045 (7).

As the inhibition of enzymes involved in the hydrolysis of carbohydrates in the digestive tract is a current diabetes treatment, in vitro studies have been conducted on the inhibition of diabetic enzymes such as α-amylase, α-glucosidase, and aldose reductase (3,8,9). The inhibition of these enzymes restricts the digestion of dietary carbohydrates and thus inhibits simple sugar absorption, causing low postprandial glucose levels in the blood. Increased utilization of glucose by the aldose reductase enzyme plays a crucial part in the incidence of diabetic complications (10); inhibiting the enzyme has been shown to avert diabetes complications, especially cataracts and retinopathy (11).

Per the authors of the paper, 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 (EFSA) data. While antidiabetic activity was observed in the ready-made samples purchased from an herbalist, trans-cinnamaldehyde or coumarin compounds were not detected in the HPLC analysis.

The authors concluded that the source of the cinnamon spice is crucial for the utilization of cinnamon both in food and therapeutic purposes, and that their research confirms the importance of meticulous inspection of the products sold by herbalists (1).

Fresh cinnamon sticks and powder. © philipphoto - stock.adobe.com

References

1. Mancak, M.; Çalişkan, U. K. Are Cinnamon Derivatives Effective and Safe for Diabetes? Turk. J. Med. Sci. 2024, 55 (1), 313–327. DOI: 10.55730/1300-0144.5972

2. Kıncal, S.; Ceylan, O.; Görk, G. Ethnobotanical Features of Ula (Muğla/Turkey) District. Biological Diversity and Conservation 2021, 14 (1), 69–81 https://dergipark.org.tr/en/download/article-file/1199763

3. Ranasinghe, P.; Jayawardana, R.; Galappaththy, P.; et al. Efficacy and Safety of ‘True’ Cinnamon (Cinnamomum zeylanicum) as a Pharmaceutical Agent in Diabetes: A Systematic Review and Meta‐Analysis. Diabetic Med. 2012, 29 (12), 1480–1492. DOI: 10.1111/j.1464-5491.2012.03718.x

4. Beejmohun, V.; Peytavy-Izard, M.; Mignon, C.; et al. Acute Effect of Ceylon Cinnamon Extract on Postprandial Glycemia: Alpha-Amylase Inhibition, Starch Tolerance Test in Rats, and Randomized Crossover Clinical Trial in Healthy Volunteers. BMC Complementary Altern. Med. 2014, 14 (1), 1–11. DOI: 10.1186/1472-6882-14-351

5. Cao, H.; Polansky, M. M.; Anderson, R. A. Cinnamon Extract and Polyphenols Affect the Expression of Tristetraprolin, Insulin Receptor, and Glucose Transporter 4 in Mouse 3T3-L1 Adipocytes. Arch. Biochem. Biophys. 2007, 459 (2), 214–222. DOI: 10.1016/j.abb.2006.12.034

6. Siddiqui, A. A.; Siddiqui, S. A.; Suhail, A.; et al. Diabetes: Mechanism, Pathophysiology and Management-A Review. Int. J. Drug Dev. Res. 2013, 5, 1–23. https://www.itmedicalteam.pl/articles/diabetes-mechanism-pathophysiology-and-managementa-review-101424.html

7. Magliano, D. J.; Boyko, E. J. IDF Diabetes Atlas, 10th ed.; International Diabetes Federation, 2021. https://europepmc.org/article/NBK/nbk581934

8. Hayward, N. J.; McDougall, G. J.; Farag, S.; et al. Cinnamon Shows Antidiabetic Properties That Are Species-Specific: Effects on Enzyme Activity Inhibition and Starch Digestion. Plant Foods for Human Nutrition 2019, 74 (4), 544–552. https://doi.org/10.1007/s11130-019-00760-8

9. Lee, H. S. Inhibitory Activity of Cinnamomum cassia Bark-Derived Component Against Rat Lens Aldose Reductase. J. Pharm. Pharm. Sci. 2002, 5 (3), 226–230.

10. Snow, A.; Shieh, B.; Chang, K. C.; et al. Aldose Reductase Expression as a Risk Factor for Cataract. Chem. Biol. Interact. 2015, 234, 247–253. DOI: 10.1016/j.cbi.2014.12.017

11. Patil, K. K.; Gacche, R. N. Inhibition of Glycation and Aldose Reductase Activity Using Dietary Flavonoids: A Lens Organ Culture Studies. Int. J. Biol. Macromol. 2017, 98, 730–738. DOI: 10.1016/j. ijbiomac.2017.01.129