Cinnamon and Cassia Nomenclature Confusion: A Challenge to the Applicability of Clinical Data

A Systematic Review Evaluating Cinnamon's Effects on Glucose Utilizing a Ranking System to Assess Bias and Study Quality

In the context of diabetes, the use of cinnamon continues to be among the most popular supplements taken by patients for glucose control. To strategically evaluate the available literature comparing various cinnamon species and statistically significant glucose effects after ranking studies based on two tools to assess bias and overall study quality, to clarify cinnamon's role in glucose control. The authors performed a systematic search based upon PRISMA guidelines. The search was conducted utilizing PubMed, AMED, CINAHL, EMBASE, Cochrane, and Medline databases, with the final search performed in September 2022 with restrictions to human subjects and English language. Electronic searches were conducted utilizing the keywords "diabetes mellitus" combined with Cinnamomum zeylanicum/Cinnamomum cassia/Cinnamomum verum combined with blood glucose (BG). A second search utilized "cinnamomum zeylanicum/cinnamomum cassia/cinnamomum verum" combined with "blood glucose," and a final search utilized "diabetes mellitus" combined with "cinnamon." Data extraction and ranking of included studies utilizing the risk of bias 2 tool and modified Heyland Methodological Quality Scoring tool were performed independently by two review authors. These authors compared their results and reconciled any differences in scoring to generate a final ranking of studies. A third author was available for any discrepancies that could not be resolved but was not needed. Forty-five studies were included in the review and were scored for bias and quality. Overall 62% demonstrated statistical significance for positive effects in at least one parameter around BG control. Applying the ranking systems reduced the percentage closer to 50%. Safety was extremely well documented across studies with few adverse effects. Results are limited by heterogeneity of glucose parameters, leading to studies being ranked individually and not synthesized. Cinnamon supplementation likely has a modest positive effect on BG. Based upon the strong safety profile, utilization of this spice as an adjunct to pharmacologic therapy is reasonable.

Improving the rigor and utility of botanical toxicity studies: Recommended resources

Interest in botanicals, particularly as dietary supplement ingredients, is growing steadily. This growth, and the marketing of new ingredients and combination products as botanical dietary supplements, underscores the public health need for a better understanding of potential toxicities associated with use of these products. This article and accompanying template outline the resources to collect literature and relevant information to support the design of botanical toxicity studies. These resources provide critical information related to botanical identification, characterization, pre-clinical and clinical data, including adverse effects and interactions with pharmaceuticals. Toxicologists using these resources should collaborate with pharmacognosists and/or analytical chemists to enhance knowledge of the botanical material being tested. Overall, this guide and resource list is meant to help locate relevant information that can be leveraged to inform on decisions related to toxicity testing of botanicals, including the design of higher quality toxicological studies.

Investigating the effects of Ceylon cinnamon water extract on HepG2 cells for Type 2 diabetes therapy

Cinnamon and its extracts have been used as herbal remedies for many ailments, including for reducing insulin resistance and diabetes complications. Type 2 diabetes mellitus (T2DM) is a rapidly growing health concern around the world. Although many drugs are available for T2DM treatment, side effects and costs can be considerable, and there is increasing interest in natural products for managing chronic health conditions. Cinnamon may decrease the expression of genes associated with T2DM risk. The purpose of this study was to evaluate the effects of cinnamon water extract (CWE) compared with metformin on T2DM-related gene expression. HepG2 human hepatoma cells, widely used in drug metabolism and hepatotoxicity studies, were treated with different concentrations of metformin or CWE for 24 or 48 h. Cell viability was assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay and glucose uptake was compared in untreated and CWE- or metformin-treated cells under high-glucose conditions. Finally, total RNA was extracted and analyzed by RNA sequencing (RNA-seq), and bioinformatics analyses were performed to compare the transcriptional effects of CWE and metformin. We found cell viability was better in cells treated with CWE than in metformin-treated cells, demonstrating that CWE was not toxic at tested doses. CWE significantly increased glucose uptake in HepG2 cells, to the same degree as metformin (1.4-fold). RNA-seq data revealed CWE and metformin both induced significantly increased (1.3- to 1.4-fold) glucose uptake gene expression compared with untreated controls. Transcriptional differences between CWE and metformin were not significant. The effects of 0.125 mg mL^-1 CWE on gene expression were comparable to 1.5 mg mL^-1 (9.5 mM) metformin. In addition, gene expression at 0.125 mg mL^-1 CWE was comparable to 1.5 mg mL^-1 (9.5 mM) metformin. Our results reveal that CWE's effects on cell viability, glucose uptake, and gene expression in HepG2 cells are comparable to those of metformin, suggesting CWE may be an effective dietary supplement for mitigating T2DM-related metabolic dysfunction.

Phytochemical Profiles and Biological Studies of Selected Botanical Dietary Supplements Used in the United States

Based on their current wide bioavailability, botanical dietary supplements have become an important component of the United States healthcare system, although most of these products have limited scientific evidence for their use. The most recent American Botanical Council Market Report estimated for 2020 a 17.3% increase in sales of these products when compared to 2019, for a total sales volume of $11,261 billion. The use of botanical dietary supplements products in the United States is guided by the Dietary Supplement Health and Education Act (DSHEA) from 1994, enacted by the U.S. Congress with the aim of providing more information to consumers and to facilitate access to a larger number of botanical dietary supplements available on the market than previously. Botanical dietary supplements may be formulated for and use only using crude plant samples (e.g., plant parts such as the bark, leaves, or roots) that can be processed by grinding into a dried powder. Plant parts can also be extracted with hot water to form an "herbal tea." Other preparations of botanical dietary supplements include capsules, essential oils, gummies, powders, tablets, and tinctures. Overall, botanical dietary supplements contain bioactive secondary metabolites with diverse chemotypes that typically are found at low concentration levels. These bioactive constituents usually occur in combination with inactive molecules that may induce synergy and potentiation of the effects observed when botanical dietary supplements are taken in their different forms. Most of the botanical dietary supplements available on the U.S. market have been used previously as herbal remedies or as part of traditional medicine systems from around the world. Their prior use in these systems also provides a certain level of assurance in regard to lower toxicity levels. This chapter will focus on the importance and diversity of the chemical features of bioactive secondary metabolites found in botanical dietary supplements that are responsible for their applications. Many of the active principles of botanical dietary substances are phenolics and isoprenoids, but glycosides and some alkaloids are also present. Biological studies on the active constituents of selected botanical dietary supplements will be discussed. Thus, the present chapter should be of interest for both members of the natural products scientific community, who may be performing development studies of the products available, as well as for healthcare professionals who are directly involved in the analysis of botanical interactions and evaluation of the suitability of botanical dietary supplements for human consumption.

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.

Nationwide Online Survey Enables the Reevaluation of the Safety of Coleus forskohlii Extract Intake Based on the Adverse Event Frequencies

The formulations of the functional ingredients of dietary supplements was studied with a small number of subjects, with a particular focus on their effectiveness, but not enough to evaluate their safety. In this regard, the reevaluation and estimation of the safe use of marketed products, with regards to their adverse event (AE) frequencies, are important. To address this issue, a post-marketing nationwide online survey was conducted for the herbal ingredient Coleus forskohlii extract (CFE), a popular weight-loss ingredient. The questionnaire included product names, adherence to the claimed amount, and AE experiences. The safe intake amount was estimated by the relationship between the claimed amount of CFE and the frequencies of AEs of each product. The number of users who experienced AEs was 75 (10.5% of all users). Gastrointestinal symptoms accounted for 92.0% (n = 69) of all AEs, and diarrhea alone accounted for 81.3% (n = 61). The amount of CFE was significantly associated with the occurrence of diarrhea (p = 0.005). The fitted curve showed that the safe intake amount of CFE was less than 250 mg/day; however, considering its effectiveness, 500 mg/day of CFE might be acceptable. In conclusion, nationwide online surveys of users enable us to confirm and reevaluate the safety of herbal supplements.