Toxicology and risk assessment of coumarin: Focus on human data

Effects of cinnamon supplementation on metabolic biomarkers in individuals with type 2 diabetes: a systematic review and meta-analysis

CONTEXT

The global prevalence of type 2 diabetes mellitus (DM2) has been rising significantly over the years. Recent studies have shown beneficial effects of cinnamon on metabolic biomarkers.

OBJECTIVE

The objective of this review was to assess the effect of cinnamon supplementation on metabolic biomarkers in patients with DM2.

DATA SOURCES

The Pubmed/MEDLINE, Cochrane CENTRAL, and Embase databases were searched up to November 10, 2022.

DATA EXTRACTION

A systematic search was performed for randomized controlled trials (RCTs) evaluating the effect of cinnamon supplementation on metabolic biomarkers, in adults and the elderly with DM2, and comparing the data for a cinnamon intervention group with that for a placebo group or a control group. The main exclusion criteria were studies (1) with other types of diabetes (ie, gestational diabetes or type 1 diabetes), (2) without cinnamon consumption, (3) that did not evaluate metabolic biomarkers, or (4) in vitro and animal studies. Two researchers independently screened 924 records, evaluated full-text studies, extracted data, and appraised their quality. A third researcher was consulted to resolve any discrepancies. The data were pooled using random-effects models and expressed as the weighted mean difference (WMD) with 95% CI. Heterogeneity was assessed using Cochran's Q test and quantified using I2 statistics. Risk of bias was assessed using the Joanna Briggs Institute (JBI) instrument. Sensitivity analysis and the GRADE system were used to assess the robustness and certainty of the findings.

DATA ANALYSIS

In total, 28 RCTs with a duration ranging from 30 to 120 days and a total enrollment of 3054 patients with DM2 were included. Participants consuming cinnamon showed a significant reduction in fasting blood glucose (FBG) (WMD: -15.26 mg/dL; 95% CI: -22.23 to -8.30; I2 = 88%), postprandial glucose (WMD: -39.22 mg/dL; 95% CI: -63.90 to -14.55; I2 = 100%), HbA1c (WMD: -0.56 mg/dL; 95% CI: -0.99 to -0.13; I2 = 94%), and HOMA-IR (WMD = -0.76, 95% CI: -1.13 to -0.39; I2 = 22%) compared with the control group. An intervention of cinnamon in capsule form reduced FBG (WMD:-18.43 mg/dL, 95% CI: -26.32 to -10.53; I2 = 89%), postprandial glucose (WMD: -44.83 mg/dL, 95% CI: -70.67 to -18.99; I2 = 100%), HbA1c (WMD: -0.56 mg/dL, 95% CI: -1.02 to -0.09; I2 = 94%), total cholesterol (WMD: -13.39 mg/dL; 95% CI: -24.71 to -2.07; I2 = 96%), LDL-C (WMD: -6.49 mg/dL, 95% CI: -12.69 to -0.29; I2 = 92%), and triglycerides (WND: -19.75 mg/dL; 95% CI, -33.71 to -5.80; I2 = 88%). Both doses (≤2 g/day and >2 g/day) reduced FBG and postprandial glucose. Only cinnamon doses of ≤2 g/day reduced HbA1c (WMD: -0.68 mg/dL, 95% CI: -1.16 to -0.1; I2 = 92%), HOMA-IR (WMD: -0.94 mg/dL; 95% CI: -1.21 to -0.67; I2 = 0%), and BMI (WMD: -1.18 kg/m2; 95% CI: -1.97 to -0.39; I2 = 0%).

CONCLUSION

The data suggest that cinnamon improves the glycemic and lipid profile and reduces the BMI, particularly in DM2 patients who receive cinnamon supplementation in capsule form and at a dose of ≤2 g/day.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022370332.

Potential applications of Rhodomyrtus tomentosa leaf extract as natural anti-staphylococcal additive in food systems: Efficacy and in vivo safety evaluation

This work aimed to explore the potential use of Rhodomyrtus tomentosa ethanol leaf extract (RTEL) as an alternative food preservative agent for controlling the growth of Staphylococcus aureus. Antibacterial activities against food-isolated S. aureus were performed using disc diffusion and broth microdilution assays, followed by evaluating in vivo subacute oral toxicity of the extract. Salad dressing was used as a food model to study bactericidal properties and consumer acceptability. RTEL remarkably inhibited S. aureus with minimum inhibitory concentrations (MICs) ranging from 7.81-62.5 µg/mL. Repeated oral doses (5, 50, and 300 mg/kg RTEL) for 28 days did not affect any of the measured toxicity parameters. The no-observed-adverse-effect-level (NOAEL) of RTEL was noted as more than 300 mg/kg body weight/day. The utilization of RTEL (12.5 mg/mL) in the vinaigrette salad dressing did not affect the consumer acceptability of the product, remarkably killed the pathogen within 3-9 h of exposure. The results indicated that RTEL is safe and effective as a natural anti-staphylococcal controlling agent that could be utilized in food systems. Further work is required on the effects of enterotoxin production, an important virulence factor of S. aureus responsible for food-borne disease.

The Effect of Therapeutic Doses of Culinary Spices in Metabolic Syndrome: A Randomized Controlled Trial

Non-communicable diseases (NCDs) place a significant burden on global health and the healthcare systems which support it. Metabolic syndrome is a major risk factor for a large number of NCDs; however, treatments remain limited. Previous research has shown the protective benefits of edible dietary spices on key components of metabolic syndrome. Therefore we performed a 12-week double-blind, placebo-controlled, randomized, clinical trial to evaluate the effect of ginger (Zingiber officinale), cinnamon (Cinnamomum), and black seed (Nigella sativa) consumption on blood glucose, lipid profiles, and body composition in 120 participants with, or at risk of, metabolic syndrome. Each participant consumed 3 g/day of powder (spice or placebo). Data related to different parameters were collected from participants at the baseline, midpoint, and endpoint of the intervention. Over the 12-week interventions, there was an improvement in a number of biochemical indices of metabolic syndrome, including fasting blood glucose, HbA1c, LCL, and total cholesterol associated with supplementation with the spices when compared to a placebo. This study provides evidence to support the adjunct use of supplementation for those at risk of metabolic syndrome and its sequelae.

Modulation of neuroinflammation and oxidative stress by targeting GPR55 - new approaches in the treatment of psychiatric disorders

Pharmacological treatment of psychiatric disorders remains challenging in clinical, pharmacological, and scientific practice. Even if many different substances are established for treating different psychiatric conditions, subgroups of patients show only small or no response to the treatment. The neuroinflammatory hypothesis of the genesis of psychiatric disorders might explain underlying mechanisms in these non-responders. For that reason, recent research focus on neuroinflammatory processes and oxidative stress as possible causes of psychiatric disorders. G-protein coupled receptors (GPCRs) form the biggest superfamily of membrane-bound receptors and are already well known as pharmacological targets in various diseases. The G-protein coupled receptor 55 (GPR55), a receptor considered part of the endocannabinoid system, reveals promising modulation of neuroinflammatory and oxidative processes. Different agonists and antagonists reduce pro-inflammatory cytokine release, enhance the synthesis of anti-inflammatory mediators, and protect cells from oxidative damage. For this reason, GPR55 ligands might be promising compounds in treating subgroups of patients suffering from psychiatric disorders related to neuroinflammation or oxidative stress. New approaches in drug design might lead to new compounds targeting different pathomechanisms of those disorders in just one molecule.

Coumarin-Synthetic Methodologies, Pharmacology, and Application as Natural Fluorophore

Coumarins are secondary metabolites made up of benzene and α-pyrone rings fused together that can potentially treat various ailments, including cancer, metabolic, and degenerative disorders. Coumarins are a diverse category of both naturally occurring as well as synthesized compounds with numerous biological and therapeutic properties. Coumarins as fluorophores play a key role in fluorescent labeling of biomolecules, metal ion detection, microenvironment polarity detection, and pH detection. This review provides a detailed insight into the characteristics of coumarins as well as their biosynthesis in plants and metabolic pathways. Various synthetic strategies for coumarin core involving both conventional and green methods have been discussed comparing advantages and disadvantages of each method. Conventional methods discussed are Pechmann, Knoevenagel, Perkin, Wittig, Kostanecki, Buchwald-Hartwig, and metal-induced coupling reactions such as Heck and Suzuki, as well as green approaches involving microwave or ultrasound energy. Various pharmacological applications of coumarin derivatives are discussed in detail. The structural features and conditions responsible for influencing the fluorescence of coumarin core are also elaborated.

Benzopyrone, a privileged scaffold in drug discovery: An overview of FDA-approved drugs and clinical candidates

Natural products have always served as an important source of drugs for treating various diseases. Among various privileged natural product scaffolds, the benzopyrone class of compounds has a substantial presence among biologically active compounds. One of the pioneering anticoagulant drugs, warfarin approved in 1954 bears a benzo-α-pyrone (coumarin) nucleus. The widely investigated psoriasis drugs, methoxsalen, and trioxsalen, also contain a benzo-α-pyrone nucleus. Benzo-γ-pyrone (chromone) containing drugs, cromoglic acid, and pranlukast were approved as treatments for asthma in 1982 and 2007, respectively. Numerous other small molecules with a benzopyrone core are under clinical investigation. The present review discusses the discovery, absorption, distribution, metabolism, excretion properties, and synthetic approaches for the Food and Drug Administration-approved and clinical-stage benzopyrone class of compounds. The role of the pyrone core in biological activity has also been discussed. The present review unravels the potential of benzopyrone core in medicinal chemistry and drug development.

Effect of cinnamon spice on continuously monitored glycemic response in adults with prediabetes: a 4-week randomized controlled crossover trial

BACKGROUND

Previous clinical studies showing that cinnamon spice lowers blood glucose concentrations had inconsistent results.

OBJECTIVES

To determine the effect of daily cinnamon spice supplementation in an amount commonly used for seasoning on glucose concentrations in adults with obesity and prediabetes.

METHODS

Following a 2-wk run-in period of maintaining a low polyphenol/fiber diet, 18 participants with obesity and prediabetes underwent a 10-wk randomized, controlled, double-blind, crossover trial (mean age 51.1 y; mean fasting plasma glucose 102.9 mg/dL). The participants were randomly assigned to take cinnamon (4 g/d) or placebo for 4-wk, followed by a 2-wk washout period, and then crossed over to the other intervention for an additional 4-wk. Glucose changes were measured with continuous glucose monitoring. Oral glucose tolerance testing immediately following ingestion of cinnamon or placebo was performed at 4-time points to assess their acute effects both at the baseline and end of each intervention phase. Digestive symptom logs were obtained daily.

RESULTS

There were 694 follow-up days with 66,624 glucose observations. When compared with placebo, 24-h glucose concentrations were significantly lower when cinnamon was administered [mixed-models; effect size (ES) = 0.96; 95 % confidence interval (CI): -2.9, -1.5; P < 0.001]. Similarly, the mean net-area-under-the-curve (netAUC) for glucose was significantly lower than for placebo when cinnamon was given (over 24 h; ES = -0.66; 95 % CI: 2501.7, 5412.1, P = 0.01). Cinnamon supplementation resulted in lower glucose peaks compared with placebo (Δpeak 9.56 ± 9.1 mg/dL compared with 11.73 ± 8.0 mg/dL; ES = -0.57; 95 % CI: 0.8, 3.7, P = 0.027). Glucose-dependent-insulinotropic-polypeptide concentrations increased during oral glucose tolerance testing + cinnamon testing (mixed-models; ES = 0.51; 95 % CI: 1.56, 100.1, P = 0.04), whereas triglyceride concentrations decreased (mixed-models; ES = 0.55; 95 % CI: -16.0, -1.6, P = 0.02). Treatment adherence was excellent in both groups (cinnamon: 97.6 ± 3.4 % compared with placebo: 97.9 ± 3.7 %; ES = -0.15; 95 % CI: -1.8, 0.2, P = 0.5). No differences were found in digestive symptoms (abdominal pain, borborygmi, bloating, excess flatus, and stools/day) between cinnamon and placebo groups.

CONCLUSIONS

Cinnamon, a widely available and low-cost supplement, may contribute to better glucose control when added to the diet in people who have obesity-related prediabetes. This trial was registered at clinicaltrials.gov as NCT04342624.

A historical, evidence-based, and narrative review on commonly used dietary supplements in lipid-lowering

Dietary supplements augment the nutritional value of everyday food intake and originate from the historical practices of ancient Egyptian (Ebers papyrus), Chinese (Pen Ts'ao by Shen Nung), Indian (Ayurveda), Greek (Hippocrates), and Arabic herbalists. In modern-day medicine, the use of dietary supplements continues to increase in popularity with greater than 50% of the US population reporting taking supplements. To further compound this trend, many patients believe that dietary supplements are equally or more effective than evidence-based therapies for lipoprotein and lipid-lowering. Supplements such as red yeast rice, omega-3 fatty acids, garlic, cinnamon, plant sterols, and turmeric are marketed to and believed by consumers to promote "cholesterol health." However, these supplements are not subjected to the same manufacturing scrutiny by the Food and Drug Administration as pharmaceutical drugs and as such, the exact contents and level of ingredients in each of these may vary. Furthermore, supplements do not have to demonstrate efficacy or safety before being marketed. The holistic approach to lowering atherosclerotic cardiovascular disease risk makes dietary supplements an attractive option to many patients; however, their use should not come at the expense of established therapies with proven benefits. In this narrative review, we provide a historical and evidence-based approach to the use of some dietary supplements in lipoprotein and lipid-lowering and provide a framework for managing patient expectations.

Application of urea-based magnetic covalent organic framework as sorbent for the determination of coumarin and its derivatives in food samples combined with liquid chromatography-mass spectrometry

A magnetic solid-phase extraction (MSPE) protocol using novel Urea-based magnetic covalent organic framework coupled with liquid chromatography-mass spectrometry was developed for the detection of coumarins in food samples (soft drink, biscuit and sesame paste). This adsorbent was synthesized through atom economic polymerization of tetrakis(4-aminophenyl) methane and 1,4-phenylene diisocyanate, which was successfully verified by a series of techniques. Major parameters influencing MSPE efficiency were optimized. This protocol had some advantages, such as organic-reagent-saving (2.0 mL), easy operating, short extraction time, and high repeatability (8 times). The established method exhibited superior linearity (R2 ≥ 0.999) and the limits of detection ranging from 1.0 to 5.0 µg/kg. The recoveries of coumarin and its derivatives ranged from 73.8% to 113.5% and both intra- and inter-day precision were less than 15%. These data indicate the protocol is a highly promising alternative for coumarin extraction and enrichment.

Redundant and scattered genetic determinants for coumarin biodegradation in Pseudomonas sp. strain NyZ480

Coumarin (COU) is both a naturally derived phytotoxin and a synthetic pollutant which causes hepatotoxicity in susceptible humans. Microbes have potentials in COU biodegradation; however, its underlying genetic determinants remain unknown. Pseudomonas sp. strain NyZ480, a robust COU degrader, has been isolated and proven to grow on COU as its sole carbon source. In this study, five homologs of xenobiotic reductase A scattered throughout the chromosome of strain NyZ480 were identified, which catalyzed the conversion of COU to dihydrocoumarin (DHC) in vitro. Phylogenetic analysis indicated that these COU reductases belong to different subgroups of the old yellow enzyme family. Moreover, two hydrolases (CouB1 and CouB2) homologous to the 3,4-dihydrocoumarin hydrolase in the fluorene degradation were found to accelerate the generation of melilotic acid (MA) from DHC. CouC, a new member from the group A flavin monooxygenase, was heterologously expressed and purified, catalyzing the hydroxylation of MA to produce 3-(2,3-dihydroxyphenyl)propionate (DHPP). Gene deletion and complementation of couC indicated that couC played an essential role in the COU catabolism in strain NyZ480, considering that the genes involved in the downstream catabolism of DHPP have been characterized (Y. Xu and N. Y. Zhou, Appl Environ Microbiol 86:e02385-19, 2020) and homologous catabolic cluster exists in strain NyZ480. This study elucidated the genetic determinants for complete degradation of COU by Pseudomonas sp. strain NyZ480.IMPORTANCECoumarin (COU) is a phytochemical widely distributed in the plant kingdom and also artificially produced as an ingredient for personal care products. Hence, the environmental occurrence of COU has been reported in different places. Toxicologically, COU was proven hepatotoxic to individuals with mutations in the CYP2A6 gene and listed as a group 3 carcinogen by the International Agency for Research on Cancer and thus has raised increasing concerns. Until now, different physicochemical methods have been developed for the removal of COU, whereas their practical applications were hampered due to high cost and the risk of secondary contamination. In this study, genetic evidence and biochemical characterization of the COU degradation by Pseudomonas sp. strain NyZ480 are presented. With the gene and strain resources provided here, better managements of the hazards that humans face from COU could be achieved, and the possible microbiota-plant interaction mediated by the COU-utilizing rhizobacteria could also be investigated.

Efficacy and Safety of the Phytochemical Product Linfadren in the Management of Patients With Persistent Ankle Edema Following Trauma or Surgery: A Randomized Controlled Trial

BACKGROUND

Persistent posttraumatic/postsurgery ankle edema (PPAE) is edema that persists from 2 weeks to 3 months after injury or surgery. PPAE has negative effects on the healing process and quality of life. This study aimed to evaluate the efficacy of a phytochemical product containing diosmin, coumarin, and arbutin (Linfadren) in addition to the conventional treatment, in patients with PPAE.

METHODS

Between October 2018 and February 2020, 60 outpatients with PPAE (42 with ankle fractures and 18 with ankle sprains) were enrolled and randomized (1:1 ratio) to receive either 6-week conventional treatment plus Linfadren (study group) or conventional treatment alone (control group). Primary outcome was ankle edema as measured by the "figure-of-8-20" method. Secondary outcomes were ankle function measured by the Lower Extremity Functional Scale (LEFS), and patient's overall perceived treatment efficacy. Tolerability of Linfadren was also evaluated. Assessments were performed at baseline, at end of treatment (6 weeks after baseline), and 3 months after the end of treatment (follow-up). A subgroup analysis was also conducted for the injury type (fracture/sprain) to identify if this factor affected the results of the primary outcome measure.

RESULTS

At the end of treatment, the study group had a significantly greater improvement in ankle edema, improved ankle function, and more patients who considered this treatment effective compared with the control group. The measured difference in circumference by the figure-of-8-20 method averaged 4% at 6 weeks and 5% at 3 months. No difference between groups was seen in rescue medication. No adverse events were recorded. Subgroup analysis revealed no significant influence of the injury type on the primary outcome measure.

CONCLUSION

Linfadren in addition to conventional treatment was more effective than conventional treatment alone in patients with PPAE.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

Differentiating True and False Cinnamon: Exploring Multiple Approaches for Discrimination

This study presents a comprehensive literature review that investigates the distinctions between true and false cinnamon. Given the intricate compositions of essential oils (EOs), various discrimination approaches were explored to ensure quality, safety, and authenticity, thereby establishing consumer confidence. Through the utilization of physical-chemical and instrumental analyses, the purity of EOs was evaluated via qualitative and quantitative assessments, enabling the identification of constituents or compounds within the oils. Consequently, a diverse array of techniques has been documented, encompassing organoleptic, physical, chemical, and instrumental methodologies, such as spectroscopic and chromatographic methods. Electronic noses (e-noses) exhibit significant potential for identifying cinnamon adulteration, presenting a rapid, non-destructive, and cost-effective approach. Leveraging their capability to detect and analyze volatile organic compound (VOC) profiles, e-noses can contribute to ensuring authenticity and quality in the food and fragrance industries. Continued research and development efforts in this domain will assuredly augment the capacities of this promising avenue, which is the utilization of Artificial Intelligence (AI) and Machine Learning (ML) algorithms in conjunction with spectroscopic data to combat cinnamon adulteration.

4-hydroxylonchocarpin and corylifol A: The potential hepatotoxic components of Psoralea corylifolia L

Psoralea corylifolia L. (P. corylifolia) has attracted increasing attention because of its potential hepatotoxicity. In this study, we used network analysis (toxic component and hepatotoxic target prediction, proteinprotein interaction, GO enrichment analysis, KEGG pathway analysis, and molecular docking) to predict the components and mechanism of P. corylifolia-induced hepatotoxicity and then selected 4-hydroxylonchocarpin and corylifol A for experimental verification. HepG2 cells were treated with low, medium, and high concentrations of 4-hydroxylonchocarpin or corylifol A. The activities of ALT, AST, and LDH in cell culture media and the MDA level, SOD activity, and GSH level in cell extracts were measured. Moreover, apoptosis, ROS levels, and mitochondrial membrane potential were evaluated. The results showed that the activities of ALT, AST, and LDH in the culture medium increased, and hepatocyte apoptosis increased. The level of MDA increased, and the activity of SOD and level of GSH decreased, and the ROS level increased with 4-hydroxylonchocarpin and corylifol A intervention. Furthermore, the mitochondrial membrane potential decreased in the 4-hydroxylonchocarpin and corylifol A groups. This study suggests that 4-hydroxylonchocarpin and corylifol A cause hepatocyte injury and apoptosis by inducing oxidative stress and mitochondrial dysfunction, suggesting that these compounds may be the potential hepatotoxic components of P. corylifolia.

Evaluation of on-site testing methods with a novel 3-in-1 miniaturized spectroscopic device for cinnamon screening

"True cinnamon" is often fraudulently replaced by other varieties for economic reasons. In the powdered form, it is not possible to distinguish the varieties visually, but they differ in their sensory profile, in particular in the aromatic compound coumarin content which has also been deemed hepatotoxic in animal models. Molecular and analytical techniques exist which can be used for authentication but are expensive, time-consuming, and destructive. As an alternative, we tested three different miniaturized spectroscopic techniques namely, ultraviolet-visible (UV-Vis), near-infrared (NIR) and fluorescence (FLUO) to authenticate cinnamon samples. Out of the three, UV-Vis and NIR were superior to FLUO. The separation with UV-Vis and FLUO could be visually identified after pre-processing the spectral data and subsequently submitting it to principal component analysis (PCA). When chemometrics were applied a correct classification rate by variety of 89%, 90% and 89% for UV-Vis, NIR, and fluorescence spectroscopy, respectively, was observed. The usage of miniaturized spectrophotometers combined with PCA and classification algorithms was found promising to authenticate cinnamon.

Effect of PCL nanofiber mats coated with chitosan microcapsules containing cinnamon essential oil for wound healing

INTRODUCTION

Cinnamon is one of the most common spices that has been studied for its anti-inflammatory, antioxidant, and antibacterial properties in wound healing. The purpose of this study was to evaluate the effectiveness of polycaprolactone nanofiber mats coated with chitosan microcapsules loaded with cinnamon essential oil in wound healing.

MATERIAL AND METHODS

For this purpose, chitosan microcapsules containing cinnamon essential oil (µCS-CiZ) were prepared by ion gelation and PCL nanofibers by electrospinning. The size of the µCS-CiZ and the morphology of nanofibers were evaluated by DLS and FESEM methods. In order to evaluate wound healing, 48 rats in 4 groups of Control, µCS-CiZ, PCL, and PCL + µCS-CiZ and were examined on days 7, 14, and 21 in terms of macroscopy (wound closure rate) and histology (edema, inflammation, vascularity, fibrotic tissue, and re-epithelialization).

RESULTS

The particle size of the µCS-CiZ and the diameter of the nanofibers were estimated at about 6.33 ± 1.27 μm and 228 ± 33 nm, respectively. On day 21, both µCS-CiZ and PCL groups showed a significant decrease in wound size compared to the control group (P < 0.001). The PCL + µCS-CiZ group also showed a significant decrease compared to the µCS-CiZ (P < 0.05) and PCL groups (P < 0.05). Histological results showed further reduction of edema, inflammation, and vascularity in granulation tissue and appearance of moderate to marked fibrotic tissue in PCL + µCS-CiZ group compared with the other groups.

CONCLUSION

The results of the study showed that the combined use of PCL + µCS-CiZ indicates a synergistic effect on improving wound healing.

Plant Coumarins with Anti-HIV Activity: Isolation and Mechanisms of Action

This review summarizes and systematizes the literature on the anti-HIV activity of plant coumarins with emphasis on isolation and the mechanism of their antiviral action. This review summarizes the information on the anti-HIV properties of simple coumarins as well as annulated furano- and pyranocoumarins and shows that coumarins of plant origin can act by several mechanisms: inhibition of HIV reverse transcriptase and integrase, inhibition of cellular factors that regulate HIV-1 replication, and transmission of viral particles from infected macrophages to healthy ones. It is important to note that some pyranocoumarins are able to act through several mechanisms or bind to several sites, which ensures the resistance of these compounds to HIV mutations. Here we review the last two decades of research on the anti-HIV activity of naturally occurring coumarins.

Species Specificity and Selection of Models for Drug Oxidations Mediated by Polymorphic Human Enzymes

Many drug oxygenations are mainly mediated by polymorphic cytochromes P450 (P450s) and also by flavin-containing monooxygenases (FMOs). More than 50 years of research on P450/FMO-mediated drug oxygenations have clarified their catalytic roles. The natural product coumarin causes hepatotoxicity in rats via the reactive coumarin 3,4-epoxide, a reaction catalyzed by P450 1A2; however, coumarin undergoes rapid 7-hydroxylation by polymorphic P450 2A6 in humans. The primary oxidation product of the teratogen thalidomide in rats is deactivated 5'-hydroxythalidomide plus sulfate and glucuronide conjugates; however, similar 5'-hydroxythalidomide and 5-hydroxythalidomide are formed in rabbits in vivo. Thalidomide causes human P450 3A enzyme induction in liver (and placenta) and is also activated in vitro and in vivo by P450 3A through the primary human metabolite 5-hydroxythalidomide (leading to conjugation with glutathione/nonspecific proteins). Species differences exist in terms of drug metabolism in rodents and humans, and such differences can be very important when determining the contributions of individual enzymes. The approaches used for investigating the roles of human P450 and FMO enzymes in understanding drug oxidations and clinical therapy have not yet reached maturity and still require further development. SIGNIFICANCE STATEMENT: Drug oxidations in animals and humans mediated by P450s and FMOs are important for understanding the pharmacological properties of drugs, such as the species-dependent teratogenicity of the reactive metabolites of thalidomide and the metabolism of food-derived odorous trimethylamine to non-odorous (but proatherogenic) trimethylamine N-oxide. Recognized differences exist in terms of drug metabolism between rodents, non-human primates, and humans, and such differences are important when determining individual liver enzyme contributions with substrates in in vitro and in vivo systems.

Coumarin-Induced Hepatotoxicity: A Narrative Review

Coumarin is an effective treatment for primary lymphoedema, as well as lymphoedema related to breast cancer radiotherapy or surgery. However, its clinical use is limited in several countries due to the possible occurrence of hepatotoxicity, mainly in the form of mild to moderate transaminase elevation. It is worth noting that only a few cases of severe hepatotoxicity have been described in the literature, with no reported cases of liver failure. Data available on coumarin absorption, distribution, metabolism, and excretion have been reviewed, focusing on hepatotoxicity studies carried out in vitro and in vivo. Finally, safety and tolerability data from clinical trials have been thoroughly discussed. Based on these data, coumarin-induced hepatotoxicity is restricted to a small subset of patients, probably due to the activation in these individuals of alternative metabolic pathways involving specific CYP450s isoforms. The aim of this work is to stimulate research to clearly identify patients at risk of developing hepatotoxicity following coumarin treatment. Early identification of this subset of patients could open the possibility of more safely exploiting the therapeutical properties of coumarin, allowing patients suffering from lymphoedema to benefit from the anti-oedematous activity of the treatment.

Phenolic Compounds in Active Packaging and Edible Films/Coatings: Natural Bioactive Molecules and Novel Packaging Ingredients

In recent years, changing lifestyles and food consumption patterns have driven demands for high-quality, ready-to-eat food products that are fresh, clean, minimally processed, and have extended shelf lives. This demand sparked research into the creation of novel tools and ingredients for modern packaging systems. The use of phenolic-compound-based active-packaging and edible films/coatings with antimicrobial and antioxidant activities is an innovative approach that has gained widespread attention worldwide. As phenolic compounds are natural bioactive molecules that are present in a wide range of foods, such as fruits, vegetables, herbs, oils, spices, tea, chocolate, and wine, as well as agricultural waste and industrial byproducts, their utilization in the development of packaging materials can lead to improvements in the oxidative status and antimicrobial properties of food products. This paper reviews recent trends in the use of phenolic compounds as potential ingredients in food packaging, particularly for the development of phenolic compounds-based active packaging and edible films. Moreover, the applications and modes-of-action of phenolic compounds as well as their advantages, limitations, and challenges are discussed to highlight their novelty and efficacy in enhancing the quality and shelf life of food products.

Metabolism of phenolics in coffee and plant-based foods by canonical pathways: an assessment of the role of fatty acid β-oxidation to generate biologically-active and -inactive intermediates

ω-Phenyl-alkenoic acids are abundant in coffee, fruits, and vegetables. Along with ω-phenyl-alkanoic acids, they are produced from numerous dietary (poly)phenols and aromatic amino acids in vivo. This review addresses how phenyl-ring substitution and flux modulates their gut microbiota and endogenous β-oxidation. 3',5'-Dihydroxy-derivatives (from alkyl-resorcinols, flavanols, proanthocyanidins), and 4'-hydroxy-phenolic acids (from tyrosine, p-coumaric acid, naringenin) are β-oxidation substrates yielding benzoic acids. In contrast, 3',4',5'-tri-substituted-derivatives, 3',4'-dihydroxy-derivatives and 3'-methoxy-4'-hydroxy-derivatives (from coffee, tea, cereals, many fruits and vegetables) are poor β-oxidation substrates with metabolism diverted via gut microbiota dehydroxylation, phenylvalerolactone formation and phase-2 conjugation, possibly a strategy to conserve limited pools of coenzyme A. 4'-Methoxy-derivatives (citrus fruits) or 3',4'-dimethoxy-derivatives (coffee) are susceptible to hepatic "reverse" hydrogenation suggesting incompatibility with enoyl-CoA-hydratase. Gut microbiota-produced 3'-hydroxy-4'-methoxy-derivatives (citrus fruits) and 3'-hydroxy-derivatives (numerous (poly)phenols) are excreted as the phenyl-hydracrylic acid β-oxidation intermediate suggesting incompatibility with hydroxy-acyl-CoA dehydrogenase, albeit with considerable inter-individual variation. Further investigation is required to explain inter-individual variation, factors determining the amino acid to which C6-C3 and C6-C1 metabolites are conjugated, the precise role(s) of l-carnitine, whether glycine might be limiting, and whether phenolic acid-modulation of β-oxidation explains how phenolic acids affect key metabolic conditions, such as fatty liver, carbohydrate metabolism and insulin resistance.

Coumarins as Fungal Metabolites with Potential Medicinal Properties

Coumarins are a structurally varied set of 2H-chromen-2-one compounds categorized also as members of the benzopyrone group of secondary metabolites. Coumarin derivatives attract interest owing to their wide practical application and the unique reactivity of fused benzene and pyrone ring systems in molecular structure. Coumarins have their own specific fingerprints as antiviral, antimicrobial, antioxidant, anti-inflammatory, antiadipogenic, cytotoxic, apoptosis, antitumor, antitubercular, and cytotoxicity agents. Natural products have played an essential role in filling the pharmaceutical pipeline for thousands of years. Biological effects of natural coumarins have laid the basis of low-toxic and highly effective drugs. Presently, more than 1300 coumarins have been identified in plants, bacteria, and fungi. Fungi as cultivated microbes have provided many of the nature-inspired syntheses of chemically diverse drugs. Endophytic fungi bioactivities attract interest, with applications in fields as diverse as cancer and neuronal injury or degeneration, microbial and parasitic infections, and others. Fungal mycelia produce several classes of bioactive molecules, including a wide group of coumarins. Of promise are further studies of conditions and products of the natural and synthetic coumarins’ biotransformation by the fungal cultures, aimed at solving the urgent problem of searching for materials for biomedical engineering. The present review evaluates the fungal coumarins, their structure-related peculiarities, and their future therapeutic potential. Special emphasis has been placed on the coumarins successfully bioprospected from fungi, whereas an industry demand for the same coumarins earlier found in plants has faced hurdles. Considerable attention has also been paid to some aspects of the molecular mechanisms underlying the coumarins’ biological activity. The compounds are selected and grouped according to their cytotoxic, anticancer, antibacterial, antifungal, and miscellaneous effects.

Effects of cinnamon supplementation on lipid profiles among patients with metabolic syndrome and related disorders: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Studies in animals and humans have reported numerous beneficial effects of cinnamon. However, its hypolipidemic efficacy in patients with metabolic syndrome (MetS) and related disorders is still controversial. This meta-analysis aimed to evaluate the lipid-regulating effects and safety of cinnamon in a population with MetS and related disorders.

METHODS

Studies that met the inclusion criteria were retrieved from PubMed, Embase, Cochrane Library, and Web of Science. Randomized placebo-controlled trials of cinnamon or its extracts in the treatment of MetS and related metabolic diseases were the main eligibility criteria. The Cochrane Handbook was used to guide the study selection, quality assessment, and data analysis. All statistical analyses were performed using Stata 15.0.

RESULTS

Twelve studies involving 773 subjects were included in the meta-analysis. The overall results showed that cinnamon could significantly reduce total cholesterol (weighted mean difference [WMD]: -0.19 mmol/L [-7.34 mg/dL]; 95% confidence interval [CI]: -0.24, -0.14 [-9.27, -5.41]), triglyceride (WMD: -0.10 mmol/L [-8.85 mg/dL]; 95% CI: -0.16, -0.04 [-14.16, -3.54]), and low-density lipoprotein cholesterol (WMD: -0.16 mmol/L [-6.18 mg/dL]; 95% CI: -0.20, -0.11 [-7.72, -4.25]). In the subgroup analysis, cinnamon did not exhibit a significant effect on lipid profiles in European and American patients. Larger doses of cinnamon tended to exhibit better regulation of lipid profiles and high-dose cinnamon (≥1.5 g/d) significantly increased high-density lipoprotein cholesterol (WMD: 0.07 mmol/L [2.70 mg/dL]; 95% CI: 0.03, 0.11 [1.16, 4.25]).

CONCLUSION

The current evidence shows that cinnamon can regulate lipid profiles in patients with metabolic disorders.

Development of a Metabolite Ratio Rule-Based Method for Automated Metabolite Profiling and Species Differentiation of Four Major Cinnamon Species

A metabolomic ratio rule-based classification method was developed and programmed for automated metabolite profiling and differentiation of four major cinnamon species using ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS). The computational program identifies key cinnamon metabolites, including proanthocyanidins, cinnamaldehyde, and coumarin, from test samples through LC-MS data processing and assigns cinnamon species by critical metabolite ratios using a stepwise classification strategy. Further, 100% classification accuracy was achieved on the training sample set through critical ratio optimization, and over 95% accuracy was achieved on the validation sample set. The proposed cinnamon classification method exhibited superior accuracy compared to the metabolomic-based PLS-DA modeling method and offered great value for the authentication of cinnamon samples and evaluation of their potential health benefits.

Angelol-A exerts anti-metastatic and anti-angiogenic effects on human cervical carcinoma cells by modulating the phosphorylated-ERK/miR-29a-3p that targets the MMP2/VEGFA axis

AIMS

Angelol-A (Ang-A), a kind of coumarins, is isolated from the roots of Angelica pubescens f. biserrata. However, AA exerts antitumor effects and molecular mechanism on cervical cancer cells is unknown.

MAIN METHODS

Cell viability was determined using the MTT assay, and the cell cycle phase was assessed by PI staining with flow cytometry. Ang-A-treated cells with/without Antago-miR-29a-3p (miR-29a-3p inhibitor) or U0126 (MEK inhibitor) were assessed for the expression of miR-29a-3p, in vitro migration/invasion, and angiogenesis using qRT-PCR, a chemotaxis assay, and tube formation assay, respectively. The expression of mitogen-activated protein kinases/MMP2/MMP9/VEGFA was determined by western blot analysis with applicable antibodies.

KEY FINDINGS

Ang-A significantly inhibited MMP2 and VEGFA expression, cell migration, and invasive motility in human cervical cancer cells. Conditioned medium inhibited tube formation in HUVECs. Ang-A principally inhibited invasive motility and angiogenesis by upregulating the expression of miR-29a-3p that targets the VEGFA-3' UTR. The role of miR-29a-3p was confirmed using Antago-miR-29a-3p, which reversed the Ang-A-inhibited expression of MMP2 and VEGFA, invasive motility, and angiogenesis in human cervical cancer cells. The ERK pathway was implicated in mediating the metastatic and angiogenic action of Ang-A. Combined treatment with Ang-A treated and U0126 exerted a synergistic inhibitory effect on the expression of MMP2 and VEGFA and the metastatic and angiogenic properties of human cervical cancer cells.

SIGNIFICANCE

These findings are the first to indicate that in human cervical cancer cells, Ang-A exerts anti-metastatic and anti-angiogenic effects via targeting the miR-29a-3p/MMP2/VEGFA axis, mediated through the ERK pathway.

Implications for herbal polypharmacy: coumarin-induced hepatotoxicity increased through common herbal phytochemicals astragaloside IV and atractylenolide I

Hepatotoxicity is a well-known adverse effect of many substances, with toxicity often resulting from interactions of drugs with other drug-like substances. With the increased availability of complementary and alternative medicines, including herbal medicines, the likelihood of adverse interactions between drugs and drug-like substances in herbs increases. However, the impact of potential herb-herb interactions is little understood. To assess the potential of two cytochrome P450 enzyme modulating phytochemicals common to many herbal medicines, atractylenolide I (ATR-I) and astragaloside IV (AST-IV), to interact with coumarin, another phytochemical common in many foods, a hepatocyte function model with a liver carcinoma cell line, HepG2, was exposed to these agents. To determine the effects of cytochrome P450 modulation by these phytochemicals certain cells were induced with rifampicin to induce cytochrome P450. Increasing concentrations of ATR-I combined with a fixed, nontoxic concentration of coumarin (200 µM), demonstrated significant additive interactions. 300 µM ATR-I produced a 31% reduction in cell viability (p < 0.01) with coumarin in rifampicin uninduced cells. In rifampicin-induced cells, ATR-I (100-300 µM) produced a significant reduction in cell viability (p < 0.01) with coumarin (200 µM). AST-IV with fixed coumarin (200 µM) showed 27% toxicity at 300 µM AST-IV in rifampicin uninduced cells (p < 0.05) and 30% toxicity in rifampicin induced cells (p < 0.05). However, when fixed coumarin and AST-IV were combined with increasing concentrations of ATR-I no further significant increase in toxicity was observed (p > 0.05). These results demonstrate the potential toxic interactive capabilities of common traditional Chinese herbal medicine phytochemicals and underline the potential importance of coumarin-mediated toxicity.

Safety Profile of Nutraceuticals Rich in Coumarins: An Update

Coumarins are a family of benzopyrones largely distributed in the natural kingdom, being present in the seeds, fruits, flowers, or roots of various plant species. Natural coumarin compounds are found in significant concentrations in some herbs or spices used as nutraceuticals, but they are also present in cosmetics or household products, due to their pleasant odor. Therefore, an accidental exposure to high doses of coumarins, could lead to the development of harmful effects in some patients. This review summarizes the latest published data from preclinical and clinical studies with natural coumarins, focused on the investigation of general and specific toxicity, with the aim of a better understanding of the safety profile of these valuable compounds. Regulatory aspects concerning the use of natural coumarins in several world regions are also reviewed.

Safety of Cinnamon: An Umbrella Review of Meta-Analyses and Systematic Reviews of Randomized Clinical Trials

Purpose: Many evidence-based studies have indicated that cinnamon has therapeutic effects. However, it may not be entirely safe and its adverse effects may be ignored. The present umbrella review was conducted to elucidate the safety of cinnamon.

Methods: Pertinent meta-analyses and systematic reviews of randomized controlled trials on cinnamon use in humans were identified by searching PubMed, EMBASE, and the Cochrane Library from their inception to September 15, 2021. All meta-analyses and systematic reviews on the safety or adverse effects of cinnamon were considered. PRISMA 2020 was used as the standard of reporting (PRISMA registration ID: 286746).

Results: We identified three meta-analyses and one systematic review that described the safety of cinnamon. The quality of the meta-analysis and systematic reviews was evaluated using “Assessing the Methodological Quality of Systematic Reviews.” Their quality was rated as low in two (50%) instances and moderate in two (50%). There were no significant toxic- or side effects between cinnamon group and placebo group regardless of dose and duration.

Conclusion: There is evidence to support that the use of cinnamon has no adverse reactions. It can improve the health status of patients as an adjuvant treatment. Future studies exploring better profile risks and protective factors for cinnamon use-related adverse effect are needed, in order that preventive approaches can be developed.

Combined Risk Assessment of Food-derived Coumarin with <i>in Silico</i> Approaches

Hepatotoxicity associated with food-derived coumarin occurs occasionally in humans. We have, herein, assessed the data of existing clinical and nonclinical studies as well as those of in silico models for humans in order to shed more light on this association. The average intakes of food-derived coumarin are estimated to be 1−3 mg/day, while a ten-times higher level is expected in the worst-case scenarios. These levels are close to or above the tolerable daily intake suggested by a chronic study in dogs. The human internal exposure levels were estimated by a physiologically-based pharmacokinetic model with the use of virtual doses of coumarin in the amounts expected to derive from foods. Our results suggest that: (i) coumarin can be cleared rapidly via 7-hydroxylation in humans, and (ii) the plasma levels of coumarin and of its metabolite, o-hydroxyphenylacetic acid associated with hepatotoxicity, are considerably lower than those yielding hepatotoxicity in rats. Pharmacokinetic data suggest a low or negligible concern regarding a coumarin-induced hepatotoxicity in humans exposed to an average intake from foods. Detoxification of coumarin through the 7-hydroxylation, however, might vary among individuals due to genetic polymorphisms in CYP2A6 enzyme. In addition, the CYP1A2- and CYP2E1-mediated activation of coumarin can fluctuate as a result of induction caused by environmental factors. Furthermore, the daily consumption of food-contained coumarin was implicated in the potential risk of hepatotoxicity by the drug-induced liver injury score model developed by the US Food and Drug Administration. These results support the idea of the existence of human subpopulations that are highly sensitive to coumarin; therefore, a more precise risk assessment is needed. The present study also highlights the usefulness of in silico approaches of pharmacokinetics with the liver injury score model as battery components of a risk assessment.

Clean vs dirty labels: Transparency and authenticity of the labels of Ceylon cinnamon

Ceylon cinnamon, which was regarded as a luxury spice during ancient times, has been consumed for its medicinal properties and health benefits for thousands of years. For centuries, Arabian traders controlled the European cinnamon trade through limited supplies from a country which they did not reveal. Content marketing analysis and chemical profiling of value-added products of Ceylon cinnamon in the global marketplace are proposed to investigate the clean status of the product labels. In the present study, a mixed-method approach was employed to investigate the labels of 6 types of value-added forms of cinnamon; i.e. quills, powder, tea, breakfast cereals, confectionery and bakery and nutraceuticals which are used in USA, UK, Mexico, Japan and products of Sri Lankan cinnamon exporters. Two hundred and seventy-six labels were analyzed to find out the aspects of clean status, transparency and authenticity. Key label claims of the cinnamon products lie within the bounds of cleaner, healthy, nutritional and sustainable attributes. Consumer perception lies within ingredients, nutritional value, country of origin and claim on safety and quality standards and certification. The value chain transparency, ethical rules (species mislabeling), and chemical profile of the pharmaceutical, confectionery and fragrance industry inputs were ignored. The best claim and competitive advantage of the Ceylon cinnamon; an ultra-low level (<0.01 mg/g Dry Weight) of Coumarin, were rarely indicated in labels. Lack of clean labels and traceability lagged Ceylon cinnamon in the 40 international markets while Cassia cinnamon (Coumarin content 2.23 mg/g DW), a major competitor of Ceylon cinnamon appears in the market with dirty labels. Millennials and upper-middle-class female consumers in their active ages, place a high demand on Ceylon cinnamon. Today's tech-savvy global consumers of Ceylon cinnamon use market intelligence frequently for identifying product authenticity. Well equipped clean labels were found to be demanded by the modern cinnamon consumers.

Roles of human cytochrome P450 1A2 in coumarin 3,4-epoxidation mediated by untreated hepatocytes and by those metabolically inactivated with furafylline in previously transplanted chimeric mice

Coumarin is a naturally occurring component of food products but is of clinical interest for its potential hepatotoxicity in humans. In the current study, the pharmacokinetics of coumarin in humanized-liver mice after oral and intravenous administrations (30 mg/kg) were investigated for its transformations to metabolically active coumarin 3,4-epoxide (as estimated by the levels of o-hydroxyphenylacetic acid) and to excretable 7-hydroxycoumarin. After oral administration, control mice metabolized coumarin to o-hydroxyphenylacetic acid at roughly the same rate as that to 7-hydroxycoumarin (total of unconjugated and conjugated forms). In contrast, the in vivo biotransformation of coumarin to o-hydroxyphenylacetic acid by humanized-liver mice was around two orders of magnitude less than that to conjugated and unconjugated 7-hydroxycoumarin. After intravenous administrations of coumarin, differences were observed in the plasma concentrations of o-hydroxyphenylacetic acid between humanized-liver mice treated with furafylline (daily oral doses of 13 mg/kg for 3 days) and untreated humanized-liver mice. The mean values of the areas under the plasma concentration versus time curves and the maximum concentrations for o-hydroxyphenylacetic acid were significantly lower in the group treated with furafylline (45% and 57% of the untreated values, respectively). These results suggested that the metabolic activation of coumarin in humans was mediated mainly by P450 1A2, which was suppressed by furafylline, and that humanized-liver mice orally treated with furafylline might constitute an in vivo model for metabolically inactivated P450 1A2 in human hepatocytes transplanted into chimeric mice.

Generation of Tetrafluoroethylene-Propylene Elastomer-Based Microfluidic Devices for Drug Toxicity and Metabolism Studies

Polydimethylsiloxane (PDMS) is widely used to fabricate microfluidic organs-on-chips. Using these devices (PDMS-based devices), the mechanical microenvironment of living tissues, such as pulmonary respiration and intestinal peristalsis, can be reproduced in vitro. However, the use of PDMS-based devices in drug discovery research is limited because of their extensive absorption of drugs. In this study, we investigated the feasibility of the tetrafluoroethylene-propylene (FEPM) elastomer to fabricate a hepatocyte-on-a-chip (FEPM-based hepatocyte chip) with lower drug absorption. The FEPM-based hepatocyte chip expressed drug-metabolizing enzymes, drug-conjugating enzymes, and drug transporters. Also, it could produce human albumin. Although the metabolites of midazolam and bufuralol were hardly detected in the PDMS-based hepatocyte chip, they were detected abundantly in the FEPM-based hepatocyte chip. Finally, coumarin-induced hepatocyte cytotoxicity was less severe in the PDMS-based hepatocyte chip than in the FEPM-based hepatocyte chip, reflecting the different drug absorptions of the two chips. In conclusion, the FEPM-based hepatocyte chip could be a useful tool in drug discovery research, including drug metabolism and toxicity studies.

Cinnamon as a Useful Preventive Substance for the Care of Human and Plant Health

Cinnamon is widely used as a food spice, but due to its antibacterial and pharmacological properties, it can also be used in processing, medicine and agriculture. The word “Cinnamon” can refer to the plant, processed material, or an extract. It is sometimes used as a substance, and sometimes used as a mixture or as compounds or a group. This article reviews research into the effectiveness of various forms of cinnamon for the control of plant diseases and pests in crops and during storage of fruit and vegetables. Cinnamon acts on pests mainly as a repellent, although in higher doses it has a biocidal effect and prevents egg-laying. Cinnamon and its compounds effectively hinder bacterial and fungal growth, and the phytotoxic effects of cinnamon make it a possible herbicide. This article presents the wide practical use of cinnamon for various purposes, mainly in agriculture. Cinnamon is a candidate for approval as a basic substance with protective potential. In particular, it can be used in organic farming as a promising alternative to chemical pesticides for use in plant protection, especially in preventive treatments. The use of natural products is in line with the restriction of the use of chemical pesticides and the principles of the EU’s Green Deal.

What is the influence of cinnamon supplementation on liver enzymes? A systematic review and meta-analysis of randomized controlled trials

Existing evidence has uncovered the potential health benefits of cinnamon intake; however, its effect on liver function is unclear. Thus, the aim of this systematic review and meta-analysis was to examine the effect of cinnamon supplementation on liver enzymes. Relevant articles were identified through a systematic search in PubMed/Medline, Scopus, Web of Science, Cochrane Library, and Embase up to September 2020. All trials assessing the effect of oral cinnamon supplementation on serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) in adults were included. The pooled effect sizes were obtained using the random-effects model and expressed as mean difference (MD) and 95% confidence intervals (CI). A total of seven original trials (nine treatment arms) involving a total of 256 subjects were included in the final analysis. The pooled analysis indicated that cinnamon supplementation had no significant effect on serum levels of ALT, AST, and ALP. However, there was a significant reduction in ALT levels in patients with type 2 diabetes (MD: -4.01 U/L; 95% CI: -6.86, -1.15) and in trials with low-dose supplementation (<1,500 mg/d), follow-up duration longer than 12 weeks, and in the elderly patients (aged>50 years). The beneficial effects of cinnamon intake were also shown in AST levels in patients with type 2 diabetes and trials with long-term follow-up (>12 weeks). Longer-term, oral cinnamon supplementation may improve serum levels of liver enzymes in patients with type 2 diabetes. Further high-quality studies are needed, especially in populations with abnormal liver enzyme levels, to firmly establish the clinical efficacy of cinnamon on liver function.

Cinnamomum Species: Bridging Phytochemistry Knowledge, Pharmacological Properties and Toxicological Safety for Health Benefits

The genus Cinnamomum includes a number of plant species largely used as food, food additives and spices for a long time. Different traditional healing systems have used these plants as herbal remedies to cure diverse ailments. The aim of this comprehensive and updated review is to summarize the biodiversity of the genus Cinnamomum, its bioactive compounds, the mechanisms that underlie the pharmacological activities and molecular targets and toxicological safety. All the data in this review have been collected from databases and recent scientific literature including Web of Science, PubMed, ScienceDirect etc. The results showed that the bioactive compounds of Cinnamomum species possess antimicrobial, antidiabetic, antioxidant, anti-inflammatory, anticancer and neuroprotective effects. The preclinical (in vitro/in vivo) studies provided the possible molecular mechanisms of these action. As a novelty, recent clinical studies and toxicological data described in this paper support and confirm the pharmacological importance of the genus Cinnamomum. In conclusion, the obtained results from preclinical studies and clinical trials, as well as reduced side effects provide insights into future research of new drugs based on extracts and bioactive compounds from Cinnamomum plants.

Monosubstituted Coumarins Inhibit Epinephrine-Induced Platelet Aggregation Antiplatelet Effect of Monosubstituted Coumarins

Aim

The aim of this study was to evaluate the in vitro effect of coumarin and 15 monosubstituted  derivatives on  the inhibition  of human platelet  aggregation  induced by various  pro-aggregatory agonists, particularly by epinephrine.

Background

The emergence of residual platelet reactivity during the use of conventional antiplatelet agents (acetylsalicylic acid and clopidogrel) is one of the main causes of double therapy´s therapeutic failure. Platelet adrenoceptors participate in residual platelet reactivity. Therefore, it is necessary to develop new antiplatelet agents that inhibit epinephrine-induced platelet aggregation as a new therapeutic strategy. Information on the antiplatelet activity of coumarins in inhibiting epinephrine-induced aggregation is limited.

Objective

The objective of this study was to establish the structure-activity relationship (SAR) of coumarin derivatives with hydroxy, methoxy, and acetoxy groups in different positions of the coumarin nucleus to identify the most active molecules. Moreover, this study aimed to use in silico studies to suggest potential drug targets to which the molecules bind to produce antiplatelet effects.

Methods

The platelet aggregation was performed using a Lumi-aggregometer; the inhibitory activity of 16 compounds were evaluated by inducing the aggregation of human platelets (250 × 10³/μl) with epinephrine (10 µM), collagen (2 µg/ml) or ADP (10 µM). The aggregation of control platelets was considered 100% of the response for each pro-aggregatory agonist.

Results

Eleven molecules inhibited epinephrine-induced aggregation, with 3-acetoxycoumarin and 7-methoxycoumarin being the most active. Only coumarin inhibited collagen-induced platelet aggregation, but no molecule showed activity when using ADP as an inducer.

Conclusions

In silico studies suggest that most active molecules might have antagonistic interactions in the α₂ and β₂ adrenoceptors. The antiplatelet actions of these coumarins have the potential to reduce residual platelet reactivity and thus contribute to the development of future treatments for patients who do not respond adequately to conventional agents.

Pathway for biodegrading coumarin by a newly isolated Pseudomonas sp. USTB-Z

Coumarin is widely used in personal care products and pharmaceutical industry, which leads to the release of this compound into environment as an emerging contaminant. Here, a promising strain USTB-Z for biodegrading coumarin was successfully isolated from botanical soil and characterized as a potential novel Pseudomonas sp. based on 16S rDNA sequence analysis and orthologous average nucleotide identity tool. Initial coumarin up to 800 mg/L could be completely removed by USTB-Z within 48 h at the optimal culture conditions of pH 7.3 and 30 °C, which indicates that USTB-Z has a strong capacity in coumarin biodegradation. The biodegradation products of coumarin were further investigated using HPLC and Q-TOF LC/MS, and melilotic acid and 2,3-dihydroxyphenylpropionic acid were identified. The draft genome of strain USTB-Z was sequenced by Illumina NovaSeq, and 21 CDSs for NAD (P)-dependent oxidoreductase, 43 CDSs for hydrolase, 1 CDS for FAD-depend monooxygenase, 1 CDS for 3-hydroxycinnamic acid hydroxylase, 21 CDSs for dioxygenase, and 5 CDSs for fumarylacetoacetate (FAA) hydrolase were annotated and correlated to coumarin biodegradation. The present study provides a theoretical basis and microbial resource for further research on the coumarin biodegradation.

Bergamottin and 5-Geranyloxy-7-methoxycoumarin Cooperate in the Cytotoxic Effect of Citrus bergamia (Bergamot) Essential Oil in Human Neuroblastoma SH-SY5Y Cell Line

The plant kingdom has always been a treasure trove for valuable bioactive compounds, and Citrus fruits stand out among the others. Bergamottin (BRG) and 5-geranyloxy-7-methoxycoumarin (5-G-7-MOC) are two coumarins found in different Citrus species with well-acknowledged pharmacological properties. Previously, they have been claimed to be relevant in the anti-proliferative effects exerted by bergamot essential oil (BEO) in the SH-SY5Y human neuroblastoma cells. This study was designed to verify this assumption and to assess the mechanisms underlying the anti-proliferative effect of both compounds. Our results demonstrate that BRG and 5-G-7-MOC are able to reduce the proliferation of SH-SY5Y cells, inducing apoptosis and increasing cell population in sub-G0/G1 phase. Moreover, we demonstrated the pro-oxidant activity of the two coumarins that increased reactive oxygen species and impaired mitochondrial membrane potential. From a molecular point of view, BRG and 5-G-7-MOC were able to modulate apoptosis related factors at both protein and gene levels. Lastly, we evaluated the synergistic effect of their combination, finding that the highest synergy was observed at a concentration ratio similar to that occurring in the BEO, supporting our initial hypothesis. Taken together, our results deepen the knowledge regarding the effect of BRG and 5-G-7-MOC in SH-SY5Y cells, emphasizing the relevance of their cooperation in achieving this effect.

Threatened Cretan species Chaerophyllum creticum Boiss. & Heldr.: phenolic profile by HPLC-PDA-MS and in vitro antioxidant capacity

In this study, the chemical content of the threatened Cretan endemic Chaerophyllum creticum Boiss. & Heldr. was investigated by High Performance Liquid chromatography-Photodiode Array-Mass Spectrometry (HPLC-PDA-MS) analysis. Leaves, flowers and stems of C. creticum, were extracted via maceration and were assessed for their polyphenolic composition and antioxidant capacity. The highest extraction yields were achieved by methanol and methanol/water. A total of 17 compounds were characterised in C. creticum with luteolin-7-O-glucoside being the predominant glucoside found in all the extracts. Malonic esters were present in all the extracts. The main flavonoids and phenolics were quantified by HPLC-UV in parallel to standard spectrophotometric assays which were used for the determination of the Total Polyphenol content and the Total Flavonoid Content. The antioxidant activity was assessed by two different tests: 2,2-diphenyl-1-picrylhydrazyl (DPPH•) free radical assay and the ferric reducing antioxidant power (FRAP) assay. This is the first report on the chemical content of the Cretan endemic C. creticum.

The effect of cinnamon supplementation on liver enzymes in adults: A systematic review and meta-analysis of randomized controlled trials

AIMS

The aim of this study was to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) to examine the effect of cinnamon supplementation on liver enzymes.

METHODS

A systematic search was performed in electronic databases including PubMed-Medline, Scopus, and ISI Web of Science up to November 2020. We used a random effects model to estimate pooled effect size of alanine aminotransferase (ALT), alkaline phosphatase (ALP), and aspartate aminotransferase (AST) levels.

RESULTS

Seven RCTs (9 treatment arms) fulfilled the eligibility criteria of the present meta-analysis. Overall, meta-analysis could not show any beneficial effect of cinnamon supplementation on AST, ALT, and ALP. Subgroup analyses showed that the effect of cinnamon supplementation on ALT was significant at the dosages of <1500 mg/day (Hedges's: -0.61; 95 % CI: -1.11, -0.10; P = 0.002), in trials lasting>12 weeks (Hedges's: -0.83; 95 % CI: -1.36, -0.30; P = 0.01), and in trials conducted of both gender (Hedges's: -0.72; 95 % CI: -1.45, -0.01; P = 0.04).

CONCLUSION

In summary, cinnamon supplementation had no significant effect on liver enzymes in adults. However, the effect of cinnamon on ALT levels was significant at the dosages of <1500 mg/day, in trials lasting>12 weeks, and in trials conducted of both gender. Nevertheless, further studies should be performed to confirm our results.

Metabolic activation and deactivation of dietary-derived coumarin mediated by cytochrome P450 enzymes in rat and human liver preparations

Dietary-derived coumarin is of clinical interest for its potential hepatotoxicity in humans because such toxicity is especially evident in rats. In this study, the oxidative metabolism of coumarin to active coumarin 3,4-epoxide (as judged by the formation rates of o-hydroxyphenylacetic acid) and excretable 7-hydroxycoumarin was investigated in liver fractions from rats and humans. In rat liver microsomes, the formation rate of o-hydroxyphenylacetic acid (~6 pmol/min/mg microsomal protein) from coumarin at 10 μM was dependent on the presence of liver cytosolic fractions. Rat hepatocytes mediated similar formation rates of o-hydroxyphenylacetic acid and 7-hydroxycoumarin (~0.1 nmol/hr/10⁶ cells) at 0.20-20 μM coumarin. Human hepatocytes mediated the biotransformation of coumarin to o-hydroxyphenylacetic acid at roughly similar rates to those of rat hepatocytes. In contrast, the formation rates of 7-hydroxycoumarin by human hepatocytes were around 10-fold higher at ~1 nmol/hr/10⁶ cells. In the presence of human liver cytosolic fractions, the oxidative formation rate of o-hydroxyphenylacetic acid was relatively high in cytochrome P450 (P450) 1A2-rich human liver microsomes. The inhibitory effects of furafylline/α-naphthoflavone and 8-methoxypsoralen, P450 1A2 and 2A6 inhibitors, respectively, were seen on the rates of o-hydroxyphenylacetic and 7-hydroxylation formations, respectively, in pooled human liver microsomes. Human liver microsomes selectively inactivated for P450 1A2 and 2A6 showed low rates of o-hydroxyphenylacetic acid and 7-hydroxylation formation (~20-30% of control), respectively. Among the P450 isoforms tested, recombinant human P450 1A2 predominantly mediated o-hydroxyphenylacetic formation. These results suggested that the metabolic activation and deactivation of coumarin were mediated mainly by P450 1A2 and 2A6 enzymes, respectively. The metabolic oxidation of coumarin via 3,4-epoxidation forming o-hydroxyphenylacetic acid could inform individual human risk assessments of dietary-derived coumarin, for which hepatotoxicity is especially evident in rats.