The toxic effects of cinnamon
Cinnamon components and speciesCinnamon is a spice that contains several bioactive
agents. Cinnamaldehydes give cinnamon its aroma, Coumarins (a toxin)
contribute to taste, and several compounds
including MethylHydroxyChalcone polymers (MHCPs) contribute to its systemic insulin sensitizing benefits. Beyond the three unique
compounds listed, cinnamon also contains tannins, flavonoids, glycosides, terpenoids and anthraquinones.
Cinnamon and blood sugar; anti-diabetic effects
Cinnamon exerts beneficial control effects against pro-diabetic diets in a number of ways.
Cinnamon can inhibit numerous digestive enzymes, such as
alpha-glucosidase, sucrase and potentially pancreatic amylase (although the only results were confounded with acarbose). Via inhibition of these enzymes, cinnamon can decrease the influx of glucose into systemic circulation and avoid overly significant insulin spikes.
In systemic circulation (beyond the liver) cinnamon also possesses anti-diabetic effects. A compound in cinnamon, methylhydroxychalcone polymer (MHCP), acts as an insulin mimetic on adipocytes. MHCP's effects as an insulin mimetic are dose depend, and act by
transphosphorlyating the insulin receptor on the cytoplasmic
membrance (the same mechanism as the insulin molecule itself). Its effects on glucose uptake and glycogen, however dose-dependent, seem to be time-delayed (When insulin acts within 10 minutes of reaching the cell, MHCPs take 30-60, suggesting an intra-cellular time delay).
Cinnamon has also been implicating in aiding insulin function, potentiating its effects more than 20-fold in vitro.
When ingested in human trials, cinnamon shows much promise in reducing blood glucose levels and sometimes markers of lipid metabolism (LDL, Triglycerides, Total cholesterol). There are also
intervention studies noting improved insulin sensitivity with cinnamon extract, possibly vicariously through the reduced blood glucose levels. Dosing and Coumarin avoidance
Figure 1. Major metabolic pathways (phase I) of coumarin
Coumarin is a hepatotoxic and carcinogenic phytochemicalof which cinnamon is a high source of. It is not the active compound that reduces blood sugar, but one that exists alongside the active ingredient(s). It initially had a TDI (Tolerable Daily Intake) of 2mg/kg bodyweight max, but was lowered to 0.5 and currently stands at 0.1mg/kg
bodyweight. Although a safety buffer in included in this last
recommendation, some subsets of the human population seem more susceptible due to less of a capacity to metabolize it.
This is relevant since most anti-diabetic benefits come in a dose dependent manner, in the range of 300mg/kg bodyweight. In these doses, coumarin above the TDI can easily be ingested.
The best method of coumarin avoidance appears to be through the original source of cinnamon. Ceylon cinnamon has the lowest levels of coumarin with below 190mg/kg (some samples being below detection levels) whereas Cassia( or Chinese cinnamon) contains between 700 (at best) and 12,230mg/kg (at worst).Ceylon can be detected in stick form via its numerous thin folds, whereas Cassia has less folds and a thicker appearance. They cannot be distinguished in powder form, and Cassia is more frequently used in production and manufacturing.
Via the above numbers, a 200lb human can ingest 4.78g of Ceylon Cinnamon and arrive at the 0.1mg/kg bodyweight TDI for coumarin at worst (using the highest recorded dose of courmarin in cinnamon).Using Cassia cinnamon with a coumarin will invariably place somebody above the TDI.
There seems to be little variance on coumarin absorption depending on form of cinnamon ingested. Similar serum levels and excreted levels were achieved with isolated coumarin, pill form cinnamon, tea and rice
pudding (solid food). These results were standardized to X dose of coumarin, so source of cinnamon is irrelevant.
References: (Scifinder 期刊檢索)
1. Characterization of antioxidant and antimicrobial compounds of cinnamon and ginger essential oils
2. Toxicology and risk assessment of coumarin: focus on human data 3. A Hydroxychalcone Derived from Cinnamon Functions as a Mimetic for
Insulin in 3T3-L1 Adipocytes
4. Cinnamon extract inhibits alpha-glucosidase activity and dampens postprandial glucose excursion in diabetic rats
5. Inhibitory Activity of Cinnamon Bark Species and their Combination Effect with Acarbose against Intestinal α-glucosidase and Pancreatic α-amylase
6. Isolation and Characterization of Chalcone Polymers from Cinnamon with Insulin-Like Biological Activity
7. Regulation of PTP-1 and insulin receptor kinase by fractions from cinnamon: implications for cinnamon regulation of insulin signalling 8. Insulin-like biological activity of culinary and medicinal plant aqueous
extracts in vitro
9. The potential of cinnamon to reduce blood glucose levels in patients with type 2 diabetes and insulin resistance
10. Cinnamon supplementation in patients with type 2 diabetes mellitus 11. Effects of a cinnamon extract on plasma glucose, HbA, and serum
lipids in diabetes mellitus type 2
12. Cinnamon improves glucose and lipids of people with type 2 diabetes 13. Chromium and polyphenols from cinnamon improve insulin
sensitivity
14. Cinnamon: potential role in the prevention of insulin resistance, metabolic syndrome, and type 2 diabetes
15. Solvent-assisted supercritical fluid extraction for the isolation of semivolatile flavor compounds from the cinnamons of commerce and their separation by series-coupled column gas chromatography 16. Quantification of flavoring constituents in cinnamon: high variation
of coumarin in cassia bark from the German retail market and in authentic samples from indonesia
cinnamon-containing foods compared to isolated coumarin: a four-way crossover study in human volunteers
在分別使用過兩種資料庫檢索後，發現它們雖然都是功能強 大、資料來源豐富的資料庫，但還是有各自擅長的特色，如果是 針對學術研究，論文期刊的搜索，scifinder 會比較符合上述的需 求。但如果是要結合產品研發方向，或是市場趨勢分析方面，則 Thomson 會是非常好的工具。另外，在上課時技術人員有介紹到 正式版中的”patent map”功能，我個人覺得非常實用且具賣點，但 學校購買的版本並沒有此項功能，這是我覺得比較可惜的地方。
