Cinnamon Species Research Articles

Clinical Research on Cinnamomi Cortex: A Scoping Review

There are over 250 species of cinnamon. Each has its distinct morphology and phytochemical composition, which may result in varied therapeutic effects. However, clinical studies have rarely put emphasis on the species of cinnamon being investigated. This scoping review summarized the clinical evidence of Cinnamomum cassia (also known as Cinnamomum aromaticum), which is the species of cinnamon used in traditional Chinese medicine. Electronic searches were conducted on PubMed from its inception till August 2021. Clinical studies that were published in English, stating monotherapy with Cinnamomum cassia, Cinnamomum aromaticum, or “Rou Gui” were included. The 15 included clinical studies investigated the effects of Cinnamomum cassia on type-2 diabetes patients (n=7), and healthy adults (n=8). In the type 2 diabetes population, Cinnamomum cassia supplementation of as low as 1 g/d seemed to improve HbA1c in only poorly controlled diabetes. In the healthy population, Cinnamomum cassia supplementation appeared to influence blood glucose response in a dose-dependent manner, with current studies indicating a minimum of 5 g/dto achieve significant improvement. Studies also showed potential improvement in insulin sensitivity with prolonged Cinnamomum cassia supplementation. However, there were apparent heterogeneity among studies and uncertainties regarding the accuracy of reported cinnamon species. Therefore, the therapeutic effects of Cinnamomum cassia remain inconclusive. Future larger scale and more rigorous clinical studies, with clear identification of Cinnamomum species used, are needed for more conclusive evidence of the clinical effects of Cinnamomum cassia.

Metabolomic profiling and comparison of major cinnamon species using UHPLC-HRMS.

The metabolomic profiles of four major species of cinnamon (Cinnamomum verum, C. burmannii, C. loureiroi, and C. cassia) were investigated by ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS). Thirty-six metabolites were tentatively characterized, belonging to various compound groups such as phenolic glycosides, flavan-3-ols, phenolic acids, terpenes, alkaloids, and aldehydes. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) on the HRMS data matrix resulted in a clear separation of the four cinnamon species. Coumarin, cinnamaldehyde, methoxycinnamaldehyde, cinnamoyl-methoxyphenyl acetate, proanthocyanidins, and other components varied among the four species. Such variations were used to develop a step-by-step strategy for differentiating the four cinnamon species based on their levels of pre-selected components. This study suggests a significant variation in the phytochemical compositions of different cinnamon species, which have a direct influence on cinnamon's health benefit potentials. Graphical Abstract.

Ocena aktywności biologicznej cynamonu w badaniach in vivo

Cinnamon, the bark of different species of cinnamon, is a food spice used all over the world. In medicine, cinnamon is recommended for dyspeptic conditions, fullness and flatulence, for symptomatic treatment of mild diarrhea and for the support of diabetes treatment. Cinnamon contains essential oil, whose main active ingredient is cinnamaldehyde, as well as procyanidins and terpenes. The paper presents the results of experiments performed on animals with induced diabetes assessing the antidiabetic activity of the extract, cinnamon bark oil and cinnamaldehyde. They are also described regarding spasmolytic, analgesic and cardiovascular stimulating activity.

A tale of two cinnamons: A comparative review of the clinical evidence of Cinnamomum verum and C. cassia as diabetes interventions

ObjectiveThis review investigates the effectiveness of two cinnamon species,Cinnamomum verum and C. cassia, in diabetes management; their impact on related health conditions and relevant parameters in healthy individuals and safety issues. MethodsPubMed, Cochrane Library, and ScienceDirect were searched from 2000 up to April 2018 for clinical trials using either C. verum or C. cassia in controlling blood glucose and other diabetes-related parameters and conditions. ResultsA total of twenty-five studies (n = 997) were included for reviewing clinical evidence. Among these trials, fifteen studies investigated the effects on type II diabetes mellitus (T2DM) patients (n = 831), four investigated subjects with related clinical conditions (n = 82), and six investigated healthy individuals (n = 84). Nineteen studies used C. cassia and six used C. verum. Results suggested C. cassia helped manage diabetes at 3–6 g per day, while the effectiveness of C. verum remained inconclusive. In addition, the chemical properties of C. cassia and C. verum differ considerably. Of note, C. cassia contains high levels of the potentially hepatotoxic constituent coumarin. A skin rash was the only adverse event reported. ConclusionWhile evidence supports the therapeutic benefit of C. cassia, interchangeability of C. cassia and C. verum remains inconclusive. Further research is warranted to address the effectiveness and safety of these cinnamon species. Given the potential hepatotoxicity of C. cassia, RCTs that include liver function tests are required. Robust RCTs on C. verum are recommended to establish if its efficacy can match its safety profile.

Qualitative, quantitative, and antioxidant analysis of phytochemicals present in Cinnamomum zeylanicum species

BACKGROUND: Many species of cinnamon are grown throughout the world. The bark of cinnamon has been used as a traditional medicine from ancient times. Scientific proof regarding the presence of active compounds responsible for its medicinal property in Cinnamomum zeylanicum is much needed. AIM: The present study was carried out to evaluate the phytochemical properties and anti-oxidant properties of C. zeylanicum bark. MATERIALS AND METHODS: After preliminary qualitative screening, the aqueous extract of C. zeylanicum was quantitatively assessed for total phenol, flavonoid, tannin, saponin, and coumarin. The antioxidant property was evaluated by ferric reducing antioxidant power (FRAP) assay. RESULTS AND DISCUSSION: C. zeylanicum species was found to possess different amounts of phytochemicals. Among the five components, total polyphenol content was highest in the extract. The total phenol content was around 436 mg/g, followed by saponin which was found to be around 71.25 mg, the tannin content was 43.80 mg, and the amount of flavonoid was 41.92 mg. The coumarin content was 57.70 mg. Estimation of the antioxidant potential by FRAP method indicated the maximum ferric reducing antioxidant power to be 1.377 at 1000 μg. CONCLUSION: Thus, the investigation proved the presence of several active constituents and the antioxidant potential of C. zeylanicum so that it can be used as regular food for preventing and curing diseases.

Mechanism of action and bioactivities of Cinnamomum zeylanicum essential oil against some pathogenic microbes

Background and objective The emergence of multiple drug-resistant pathogenic microorganisms leads to the search for new, safe, and effective therapeutic substances. Essential oils (EOs) of the cinnamon species are known for their biological antimicrobial and antioxidant properties. Therefore, in our study, the EO extracted from the bark of wild Cinnamomum zeylanicum grown in the green mountains of Oman was investigated to study both the aspects. Materials and methods Chemical composition of the EO was analyzed by gas chromatography–mass spectrometry, and then its antimicrobial potential was tested against different Gram-positive, Gram-negative bacteria and fungi. The minimum inhibitory concentration (MIC) was detected and a further in-depth study on the antimicrobial mode of action of the EO at the MIC concentration was studied, in addition to the determination of the antioxidant potential of the studied EO. Results and conclusion Thirty compounds were identified, and the major constituents were cinnamaldehyde (81.78%), bornyl acetate (5.33%), and cinnamyl acetate (2.82%). The antimicrobial results showed a highly significant activity against all tested microbes. The MIC of our EO ranged from 3.3 μl/ml for Gram-positive bacteria and fungi to 10 μl/ml for Gram-negative ones. The mode of action of EO at MIC concentration showed that it had a strong effect on cell viability, permeability of cell membrane, and leakage of cell constituents such as DNA, RNA, and protein from the cell membrane to outside with the lethal percent reaching 99.99%. Moreover, it was observed that the bactericidal and fungicidal effects act in a dose- and time-dependent manner and they depend on the culture condition. Finally, the EO had a strong antioxidant effect with IC50 equaling 2.3 mg. Cinnamon essential oil has a great potential as a useful agent help in combating resistant microorganisms coupled with healing of wounds according to its antioxidant activity.

Ocena aktywności biologicznej cynamonu w badaniach in vitro

Cinnamon, the bark of various species of cinnamon, is used in the food spice used throughout the world. In medicine, cinnamon bark and bark oil are used for dyspeptic ailments, fullness and bloating, and cinnamon bark products are recommended as helpful in symptomatic treatment of mild diarrhea also are recommended to support the treatment of diabetes. Cinnamon contains essential oil, whose main active ingredient is cinnamaldehyde, as well as procyanidins, terpenes. This paper presents the results of in vitro experiments on antidiabetic action, along with the mechanism of this activity as well as on antimicrobial, anti-inflammatory and cytotoxic also presented. This article also contains information on the dosage of cinnamon bark and cinnamon bark oil.

Morphological characterization of cinnamon bark and powder available in the Serbian market

In vitro and in vivo research suggests that cinnamon, which is widely used as a spice, could have significant medicinal potential. However, the problem of using this spice for medicinal purposes is that there are hundreds of species and subspecies of cinnamon plant, and although the official source for spice production is Cinnamomum verum ( zeylanicum ) – Ceylon cinnamon; C. cassia – Chinese cinnamon, and C. burmanii – Indonesian cinnamon are commonly found on the market. In powder form it is practically impossible to distinguish between these types of cinnamon without a microscope or analytical methods. The aim of the present study is the analysis of cinnamon on the Serbian market, including verification of its origin using macroscopic and microscopic methods. Bark samples were observed under a binocular magnifier ZEISS STEMI 508 with AXIOCAM ERc 5s camera to determine fine differences between species. The powder was examined under an AXIOLAB A.1 binocular microscope with AXIOCAM ERc 5s camera. During macroscopic identification, visual differences were clearly detected and results clearly showed that in toto bark of these three species of cinnamon can be differentiated even if the type and origin are not designated on the package. During microscopic observation of powdered samples, Cinnamomum burmanii was the easiest for differentiation because of the existence of authentic plates of calcium oxalate. However, more specific characters are needed in order to distinguish between Ceylon and Chinese cinnamon powder samples. One of the possible ways to overcome this problem may be through the measurement of fiber diameters where significant differences were found. Based on the obtained results it can be concluded that microscopic techniques, which are affordable, may be a useful tool for elucidation of the differences between the most commonly present cinnamon species on the market.

The complete plastid genome of Chinese cinnamon, Cinnamomum aromaticum Nees (Lauraceae)

Cinnamomum aromaticum has long been recognized and cultivated in tropical and subtropical Asia for their aromatic bark to produce cinnamon. We reported for the first time the complete plastid genome of C. aromaticum and reconstructed its phylogenetic position. The complete plastid genome is 152,754 bp in length with a quadripartite organization: a large single copy (LSC) region of 93,706 bp and a small single copy (SSC) region of 18,916 bp. Each of the two inverted repeat regions (IRa and IRb) is 20,066 bp. We recovered 128 functional genes, including 84 protein-coding genes, 36 tRNA genes and 8 rRNA genes. The phylogenetic analysis suggested that C. aromaticum and two samples of C. camphora forms a strongly supported clade, which is sister to another cinnamon species of C. verum native to Sri Lanka with strong ultrafast bootstrap support.

Dietary Indigenous Cinnamon (Cinnamomum osmophloeum) Leaf Powder Reduces Plasma Lipid in Hypercholesterolemia Hamsters

Indigenous cinnamon ( Cinnamomum osmophloeum Kaneh) is a native tree species in Taiwan and has been reported to have various bioactivities including insecticidal, larvicidal, and antimicrobial effects. The chemical finger print of C. osmophloeum is similar to that of commercial cinnamon species with lower coumarin content. The present study was aimed to investigate the antidyslipidemia effects of indigenous cinnamon ( Cinnamomum osmophloeum Kaneh) leaf powder (CoLP) on hypercholesterolemia hamsters. Hyperlipidemia was induced by high-cholesterol (HChol) diet for 4 weeks. Two percent and 5% CoLP, and gemfibrozil (positive control; 0.25%) were administered for 10 weeks following HChol diet. Control groups were fed with normal diet (ND) or ND+5% CoLP. Behavioral, physiological, and serum biochemical parameters were determined. We found that oral administration of CoLP for 10 weeks significantly reduced the HChol-induced increase of total cholesterol (TC), triglyceride, and low-density lipoprotein levels in plasma of hamsters. In addition, HChol-induced elevation of serum glutamic oxaloacetic transaminase and glutamic pyruvic transaminase levels was significantly reversed by CoLP in a dose-dependent manner, whereas blood urea nitrogen and creatinine levels were unaffected. Further standard diagnostic tests support that consumption of CoLP did not show any behavioral and morphological changes in hamsters. Furthermore, chemical composition analysis revealed that two new flavanol glycosides, kaempferol-3- O-α-l-rhamnopyranosyl-(1→2)-α-l-arabinofuranosyl-7- O-α-l-rhamnopyranoside (4) and kaempferol-3- O-β -d-apiofuranosyl-(1→2)-α-l-arabinofuranoside (5) along with 4 known flavonoid glycosides were identified in leaves of C. osmophloeum. Taken together, these results concluded that CoLP possessed strong antidyslipidemic effects. Therefore, C. osmophloeum leaves could be a safe food supplement for treating hypercholesterolemia.

Assessment of Human Health Risk of Toxic Elements Due to Cinnamon Ingestion in the Diet.

Recent studies highlighted the beneficial action of cinnamon on postprandial glycemia and LDL-cholesterol concentrations, both in healthy subjects and type 2 diabetic patients. Inclusion of 3 to 6g of cinnamon in diet revealed a beneficial effect on glucose metabolism control in non-diabetic adults during postprandial period. Given the levels of toxic elements present in cinnamon species from different countries, such large daily intakes of cinnamon can easily exceed their maximum permissible limits and, consequently, induce adverse health effects. This study aimed to investigate the elemental concentration profile in cinnamon powder products available in the Portuguese market and to assess the cumulative non-carcinogenic risk to human health due to the exposure to mixtures of such elements through the inclusion of 6g of cinnamon in diet. Concentrations of Cu, Zn, Fe, Al, Cl, Mn, and Sr were determined by wavelength dispersive X-ray fluorescence spectroscopy in different lots of eight branded and one bulk cinnamon powder products. Linear mixed models have revealed significant differences in concentrations of Zn, Fe, Al, and Cl between brands. In particular, bulk cinnamon samples presented the highest contents of Fe (475.0-490.0mgkg-1) and Al (1139.0-1336.0mgkg-1). The non-carcinogenic risk was assessed following EPA's guidelines through the hazard quotient (HQ). Estimated HQ values were lower than the USEPA guideline of 1. Additionally, the hazard index (HI), representing the combined non-carcinogenic effects of all toxic elements, revealed no potential human health risk for heavy consumers of cinnamon (HI = 0.660). AbstractGraphical ᅟ.

Comparison of morphological and chemical characteristics of two selected accessions and six wild species of genus <em>Cinnamomum</em> Schaeff

Cinnamon is increasingly becoming an important and potential foreign exchange earner and it is the most important spice in Sri Lanka. However, currently only two selected cinnamon accessions are available in Sri Lanka. Therefore, establishment of more commercial cinnamon varieties/ cultivars with high quality and yield are required. Experiments were carried out to investigate and compare of morphological and chemical characteristics of two selected cinnamon accessions (Sri Wijaya and Sri Gemunu) and six wild cinnamon species (Cinnamomum citriodorum, Cinnamomum capparu coronde, Cinnamomum litseaefolium, Cinnamomum revulorum, Cinnamomum dubium and Cinnamomum sinharajanse). Morphological characters of flower, leaf, seed and bark, yield of bark and leaf oil, and chemical characters of leaf and bark oil were examined. Leaf morphological characters; leaf shape, type of venation, leaf apex shape, leaf length and width, petiole length and leaf area were varied among species studied. Bark color, surface texture of bark, bark odor and seed color also helped to differentiate studied species. Highest mean leaf oil percentage and bark oil percentage was obtained from C. zeylanicum (Sri Gemunu) and C. zeylanicum (Sri Wijaya) respectively. The lowest mean leaf oil percentage was obtained from C. citriodorum and the lowest mean bark oil percentage was obtained from C. dubium. GC-MS analysis indicated presence of many economically important compounds such as eugenol, cinnamaldehyde, benzyl benzoate etc., in leaf and bark oil of all studied species. Abundance of considered favorable characters which are already consisted with cultivated accessions Sri Gemunu and Sri Wijaya bark and leaf oil with important characters and easy peeling ability has been observed in tested wild types, indicating the possibilities of improvement of Ceylon cinnamon for these characters through hybridization programme using wild relatives.

NMR approach for the authentication of 10 cinnamon spice accessions analyzed via chemometric tools

Quantitative NMR metabolomics approach was developed to distinguish two cinnamon species (Ceylon Cinnamon, Cinnamomum verum and Chinese Cinnamon, Cinnamomum cassia) that are interchangeably used in food products. The results of the analyses of 10 bark accessions revealed for 9 key sensory metabolites, with (E)-cinnamaldehyde as the major form. Multivariate data analyses revealed for eugenol leading presence in C. verum versus fatty acid enrichment in C. cassia. This research provides the first NMR metabolites fingerprinting of the two major cinnamon resources. Compounds related to C. verum aroma and taste were identified and quantified that can be utilized as markers for the authentication of this valuable drug. Novel insight on metabolites mediating for C. verum antidiabetic effect is also presented.

Comparative Preliminary Phytochemical and HPTLC Fingerprint profile Studies of two Cinnamon Species Commonly used in ASU Formulations

Comparative Preliminary Phytochemical and HPTLC Fingerprint profile Studies of two Cinnamon Species Commonly used in ASU Formulations

Phosphate-solubilizing fungi for efficient soil phosphorus management

Rhizosphere soil extracts obtained from eight cinnamon species and three pepper species cultivated organically were inoculated initially on Pikovskaya (PVK) medium. The twelve fungal isolates that solubilized the insoluble phosphates were further tested on the same medium added with both insoluble tricalcium phosphate and soluble dipotassium hydrogen phosphate to detect the expression of the trait in the presence of soluble phosphates in soil, for which all twelve qualified. The efficiencies of phosphate solubilization were investigated in two liquid media: PVK medium to represent soil phosphate pool and a rock phosphate (RP) medium, by determining the available phosphorus concentration in the liquid media at the end of the 24 h and 72 h incubation periods, respectively. The pH reduction in the medium was measured to ascertain the organic acid production by fungal isolates as a mechanism of solubilization. Three fungal isolates showing the highest efficiencies in phosphate solubilization were taxonomically identified based on the micromorphological characteristics and molecular techniques. Two isolates were identified as Penicillium oxalicum and Trichorderma virens and the other was belonging to the genus Aspergillus. A possible synergism between the three fungal species towards phosphate dissolution was detected using the broth culture procedure. Aspergillus sp. in combination with P. oxalicum dissolved both Ca3(PO4)2 and RP recording the highest significant dissolved phosphate levels of 893.43 (±56.768) mg P/L and 309.42 (±42.52) mg P/L, respectively, within 72 h post inoculation, making them prospective candidates for increased phosphate availability of soil phosphate pool and rock phosphates.

Cinnamomum zeylanicum (Ceylon cinnamon) as a potential pharmaceutical agent for type-2 diabetes mellitus: study protocol for a randomized controlled trial

BackgroundPrevious studies have explored the anti-diabetic effects of Cinnamomum cassia extract in vivo and in vitro. However, there are no studies at present exploring the effects of the indigenous species of Sri Lankan cinnamon (Cinnamomum zeylanicum) in patients with diabetes mellitus. The present study aims to evaluate the potential effects of Cinnamomum zeylanicum extract as a pharmaceutical agent in patients with type-2 diabetes mellitus.Methods/designThe study will be conducted as a randomized, double-blind, placebo-controlled clinical trial for a period of 4 months at the Medical Clinic, University Medical Unit, National Hospital of Sri Lanka. A total of 210 subjects with diabetes, in three equal groups, will be recruited for the study. The patients will be randomized in a 1:1:1 ratio according to the method of block randomization and the subjects will be randomly and equally assigned into two test groups (n = 70 each) and one placebo group (n = 70). The population will be stratified at randomization based on age, gender and disease severity. The treatment drug is a capsule containing Cinnamomum zeylanicum extract as the active ingredient and the placebo capsule will contain lactose monohydrate. Two doses of Cinnamomum zeylanicum extracts (250 mg and 500 mg of the cinnamon extract) will be used. The study drugs will be double blinded to both investigators and participants. The visits and the evaluations will be done as follows: screening (visit 0), 1 month (visit 1), 2 months (visit 2), 3 months (visit 3) and 4 months (visit 4). The following primary outcome measures will be evaluated: glycosylated hemoglobin (HbA1c), fasting plasma glucose (FPG) and serum insulin. Secondary outcome measures include: Body Mass Index (BMI) and other anthropometric parameters, blood pressure, total cholesterol, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL) and triglycerides (TAG). Data will be analyzed using SPSS version 14.DiscussionWe describe the protocol for a clinical trial design evaluating the effects of Cinnamomum zeylanicum (Ceylon cinnamon) in patients with type-2 diabetes mellitus. The result of the present study, positive or negative, should provide a step change in the evidence guiding current and future policies regarding the use of cinnamon dietary supplementation in patients with diabetes.Trial registrationSri Lanka Clinical Trials Registry (SLCTR), identifier: SLCTR/2017/010 (http://slctr.lk/trials/714). Registered on 5 April 2017; study protocol version 3.1 21 March 2017.

Potential of migration of active compounds from protein‐based films with essential oils to a food and a food simulant

Migration tests at different temperatures and storage periods were performed to evaluate the release of active compounds from active whey protein films (WPFs) to a food and food simulants. Whey protein film incorporated with different levels of an optimized essential oils (EOs) blend (1%, 2%, 2.7%, and 5%, w/w) were prepared by casting. This blend contained EOs from rosemary and 2 species of cinnamon. Salami was packaged with WPF and stored during 180 days at 5°C. Temperature influenced significantly the migration of compounds (P<.1). It was observed that eucalyptol was the compound that presented the highest potential of migration into 95% ethanol (v/v). After contact of film with salami, it was observed that, in general, more than 50% of active compounds released from WPF to salami. It was observed that higher amounts of active compounds were released to salami than to fatty food simulant. Results suggested that the release of compounds depends on their affinity with the food/food simulant, temperature, their concentration in packaging, and composition of food. Active packaging may ensure the quality of food due the migration of compounds from EO with antimicrobial and antioxidant activity incorporated in the film to the foodstuff.

Comparative study on major chemical constituents in volatile oil of true cinnamon (<i>Cinnamomum verum</i> Presl. syn. <i>C. zeylanicum</i> Blum.) and five wild cinnamon species grown in Sri Lanka

The genus Cinnamomum has 250 species distributed from South, East and South East Asia to Australia. There are eight species of cinnamon grown in Sri Lanka, of which, Cinnamomum verum Pres1 (syn. C. zeylanicum Blume) which is widely cultivated in the country. In addition, seven other species of wild cinnamon are also grown which are endemic to Sri Lanka which are considered wild cinnamon. In this study, six Cinnamomum species were selected namely Cinnamomum verum, Cinnamomum dubium Nees (Sinhala: Sewel Kurundu or Wal Kurundu), Cinnamomum citriodorum (Sinhala: Pangiri Kurundu), Cinnamomum rivulorum Kostermans, Cinnamomum sinharajense Kostermans, Cinnamomum capparu-corende (Sinhala: Kapuru Kurundu). Much work has been carried out with Cinnamomum verum, however, work on wild cinnamon varieties is scanty. In this backdrop, this study was carried out to identify and quantify the major chemical constituents of volatile oils obtained from bark and leaves of wild and true cinnamon species cultivated or grown in Sri Lanka. It was revealed that leaf oil of Cinnamomum verum contains significantly (p<0.05) higher percentage of volatile oil (3.23%). The highest bark oil content (3.53%) was observed in Cinnamomum sinharajense, the lowest leaf oil (0.41%) and stem bark oil (0.51%) contents were observed in the Cinnamomum rivulorum. Fifteen major volatile chemical constituents were identified by Liquid Gas Chromatographic analysis in the essential oils obtained from bark and leaf of different cinnamon species. The highest cinnamaldehyde content (67.57%) was observed in Cinnamomum verum. Cinnamomum sinharajense contained comparatively higher amount of cinnamaldehyde (57.46%) than the other wild cinnamon species. The highest euginol content (87.53%) was observed in Cinnamomum sinharajense leaf. When compared with the chemical composition of Cinnamomum dubium leaf oil, geraniol was the most abundant (24.05%) among the volatile chemical constituents. β-Caryophyllene (41.31%) was identified in Cinnamomum dubium stem bark oil. The highest Euginol (22.29%) content was present in essential oil obtained from Cinnamomum rivulorum stem bark which was not observed in other cinnamon species.

Do Cinnamon Supplements Have a Role in Glycemic Control in Type 2 Diabetes? A Narrative Review

Cinnamon (Cinnamomum sp) has been suggested to help patients with type 2 diabetes mellitus (T2DM) achieve better glycemic control, although conclusions from meta-analyses are mixed. To evaluate whether the use of cinnamon dietary supplements by adults with T2DM had clinically meaningful effects on glycemic control, as measured by changes in fasting plasma glucose (FPG) or hemoglobin A1c (HbA1c), a comprehensive PubMed literature search was performed. Eleven randomized controlled trials were identified that met our inclusion criteria that enrolled 694 adults with T2DM receiving hypoglycemic medications or not. In 10 of the studies, participants continued to take their hypoglycemic medications during the cinnamon intervention period. Studies ranged from 4 to 16 weeks in duration; seven studies were double-blind. Cinnamon doses ranged from 120 to 6,000 mg/day. The species of cinnamon used varied: seven used Cinnamomum cassia or Cinnamomum aromaticum, one used Cinnamomum zeylanicum, and three did not disclose the species. Because of the heterogeneity of the studies, a meta-analysis was not conducted. All 11 of the studies reported some reductions in FPG during the cinnamon intervention, and of the studies measuring HbA1c very modest decreases were also apparent with cinnamon, whereas changes in the placebo groups were minimal. However, only four studies achieved the American Diabetes Association treatment goals (FPG <7.2 mmol/L [130 mg/dL] and/or HbAlc <7.0). We conclude that cinnamon supplements added to standard hypoglycemic medications and other lifestyle therapies had modest effects on FPG and HbA1c. Until larger and more rigorous studies are available, registered dietitian nutritionists and other health care professionals should recommend that patients continue to follow existing recommendations of authoritative bodies for diet, lifestyle changes, and hypoglycemic drugs.

Structural characterization and bioactivity of proanthocyanidins from indigenous cinnamon (Cinnamomum osmophloeum).

Barks and twigs of common species of cinnamon with abundant proanthocyanidins are used as a spice, fold medicine or supplement. Cinnamomum osmophloeum is an endemic species in Taiwan and coumarin was not detected in the oil of the C. osmophloeum twig. The present study aimed to evaluate the relationship between the bioactivities and proanthocyanidins of C. osmophloeum twig extracts (CoTE). The n-butanol soluble fraction from CoTE was divided into 10 subfractions (F1-F10) by Sephadex LH-20 gel chromatography. The antihyperglycemic activities were examined by α-glucosidase, α-amylase and protein tyrosine phosphatase 1B inhibitory assays. Total antioxidant activities were examined by 2,2-diphenyl-1-picrylhydrazyl free radical scavenging and ferrous ion-chelating assays. The results revealed that subfractions F6-F10, with high proanthocyanidin contents, showed excellent antihyperglycemic and antioxidant activities. Subfractions F6-F10 were analyzed further by matrix-assisted laser desorption/ionization-time of flight/mass spectrometry and thiolysis-reversed-phase high-performance liquid chromatography/tandem mass spectrometry methods. The results showed that the mean degrees of polymerization of proanthocyanidins in subfractions F6-F10 ranged from 3.5 to 5.1, with the highest degrees of polymerization of proanthocyanidins reaching 8 in subfractions F8-F10. Two compounds in F6 were identified as cinnamtannin B1 and parameritannin A1. These proanthocyanidins contained at least one A-type and major B-type linkages. These results demonstrate that proanthocyanidins are associated with their antihyperglycemic and antioxidant activities in CoTE. © 2016 Society of Chemical Industry.