Beneficial effects of Cinnamomum burmannii in the treatment of diabetes mellitus

Abstract

The study investigated the effects of cinnamon in the treatment of DM employing both animal and human studies. Chemical characterization of antioxidant capacity of aqueous cinnamon extract (ACE) was employed in this study. In animal studies, young male Wistar rats were divided into, 6 groups namely, 3 normal groups: normal untreated (n=6), normal treated 75 mg/Kg cinnamon (n=6) and normal treated
150 mg/Kg (n=5); and 3 diabetic groups: diabetic untreated (n=5), diabetic treated 75 mg/Kg cinnamon (n=6) and diabetic treated 150 mg/Kg (n=5). Treated groups received ACE during 11 weeks orally. In human study, a total of 30 non-­‐diabetic subjects were selected and allocated in 2 groups namely oral glucose tolerance test (n=15) and OGTT followed by cinnamon tea administration (n=15) (6 g cinnamon/100 ml). SPSS software was used for statistical analysis. A p-­‐value ≤
0.05 was considered significant.
Data from antioxidant characterization of ACE show a high concentration of total phenols and a strong antioxidant capacity of cinnamon. The major phenolic compounds identified were cinnamaldehyde, cinnamic acid, coumarin and cinnamyl alcohol.
The results from animal study show that cinnamon treatment significantly (p<0,05) decreased food consumption in diabetic rats, but significantly increased the body weight with higher dose in diabetic rats. Glycaemia was also decreased (p<0.05) at week 3. In the heart, ACE with both doses had significant effect (p<0.05) in normal and diabetic rats, namely, increases in Mg2+, K+, Ca2+ and Fe2+ levels. In the liver, kidneyand pancreas, cinnamon treatment seemed to have no significant effect on most of cations analysed. Cinnamon administration can decrease insulin secretion in normal rats and increased the hormone in diabetic rats in a marked dose-­‐dependent manner. The distribution of left ventricle heart fibrosis slightly decreased with cinnamon treatment, especially with high dose in diabetic rats. Concerning to the distribution of pancreatic beta and alpha cells, the results show that cinnamon seems to improve the number of insulin and glucagon positive cells in diabetic rats. The human study data in non-­‐diabetic subjects revealed that postprandial BGL were lower with cinnamon tea administration. Moreover, cinnamon administration showed an improvement of BGL area under the curve following OGTT. It also leads to both a significant (p<0.05) decrease of the maximum concentration and a variation of maximum concentration of BGL in the blood.
In conclusion, the data from animal studies revealed some beneficial effects of cinnamon treatment in diabetic rats through improvement in body weight, food consumption and glycaemia. The results also suggest a possible positive influence of cinnamon on heart fibrosis prevention and on insulin secretion in diabetic animal. Moreover, cinnamon tea ingestion seemed to exert a beneficial hypoglycaemic effect in non-­‐diabetic subjects during postprandial period. The high phenolic compounds content and anti-­‐oxidant capacity may contribute to these health benefits