Safety Profile of Nutraceuticals Rich in Coumarins: An Update

The analgesic effect of curcumin and nano-curcumin in clinical and preclinical studies: a systematic review and meta-analysis

Chronic pain remains a treatment challenge. Curcumin, a natural plant product found in the Curcuma genus, has been shown to possess anti-inflammatory, antioxidant, and neuroprotective properties. In this systematic review and meta-analysis, we aimed to evaluate the efficacy of curcumin and nano-curcumin for treating chronic pain in clinical and preclinical studies. A systematic search was performed through PubMed, SCOPUS, Web of Science Core Collection, Cochrane, and Google Scholar up to April 1, 2023, using relevant keywords. Trials that met the inclusion criteria were included in this study. We applied the mean difference (MD) or standardized mean difference (SMD) in random or fixed-effects models to analyze the impact of combined trials. We also evaluated the potential risk of bias using the Higgins method for clinical studies and the SYRCLE Risk of Bias tool for animal studies. Our meta-analysis included 59 studies, comprising 29 animal studies and 30 clinical studies. Curcumin strongly reduced pain in preclinical studies, and both the intraperitoneal (SMD = 1.48; 95% CI, 0.81 to 2.14; p < 0.001, and I2 = 77.9%) and oral (SMD = 1.27; 95% CI, 1.01 to 1.55; p < 0.001, and I2 = 0.0%) administration method of curcumin had pain-relieving effects. However, the subcutaneous method (SMD = 0.24; 95% CI, - 0.89 to 1.38; p = 0.67) had no effect. The drug's efficacy within the 100-250 mg range (SMD = 1.46; 95% CI, 0.76 to 2.15; p < 0.001; and I2 = 73.4%) surpassed that observed above 250 mg (SMD = 1.23; 95% CI, 0.89 to 1.57; p < 0.001; and I2 = 0.0%). In clinical studies, nano-curcumin had a powerful effect on pain reduction compared to placebo (MD =  - 1.197; CI 95% (- 1.94 to - 0.45); p = 0.002; and I2 = 80.9%), and the effects of NSAIDs on pain were not significantly altered when used in combination with Curcuma longa extract (MD =  - 0.23; CI 95% (- 0.99 to 0.53); p = 0.554; and I2 = 92%). In addition, the effect of increased bioavailability of curcumin (MD =  - 1.54; CI 95% (- 2.06 to - 1.02); p < 0.001; and I2 = 89.6%), curcumin (MD =  - 1.35; CI 95% (- 2.451 to - 0.252); p = 0.016; and I2 = 90.8%), and nano-curcumin was greater than placebo. Our meta-analysis suggests that curcumin and nano-curcumin are effective in reducing chronic pain. These findings have important implications for pharmaceutical science and may lead to the development of new treatments for chronic pain. However, further research is needed to confirm these findings.

Extraction and Chromatographic Approaches for Coumarin, Furocoumarin, and Polymethoxyflavone Characterization in Foods

Oxygen heterocyclic compounds play a beneficial role in plants, and their presence in foods, such as Citrus fruits, cinnamon, carrots, and parsley, has been documented in recent years. Published research articles reported several extractions and chromatographic techniques for their determination. The aim of this review was to take into consideration the research articles published from 2016 to 2024 in which the authors developed extraction and chromatographic analysis methods of oxygen heterocyclic compounds in foods. The objective of this review was to assist researchers in choosing the best approach for their future work by identifying all the possible approaches to characterize coumarins, furocoumarins, and polymethoxyflavones in foodstuffs.

Natural Guardians: Natural Compounds as Radioprotectors in Cancer Therapy

Cancer remains a significant global health challenge, with millions of deaths attributed to it annually. Radiotherapy, a cornerstone in cancer treatment, aims to destroy cancer cells while minimizing harm to healthy tissues. However, the harmful effects of irradiation on normal cells present a formidable obstacle. To mitigate these effects, researchers have explored using radioprotectors and mitigators, including natural compounds derived from secondary plant metabolites. This review outlines the diverse classes of natural compounds, elucidating their roles as protectants of healthy cells. Furthermore, the review highlights the potential of these compounds as radioprotective agents capable of enhancing the body's resilience to radiation therapy. By integrating natural radioprotectors into cancer treatment regimens, clinicians may improve therapeutic outcomes while minimizing the adverse effects on healthy tissues. Ongoing research in this area holds promise for developing complementary strategies to optimize radiotherapy efficacy and enhance patient quality of life.

An Overview of the Synthesis of 3,4-Fused Pyrrolocoumarins of Biological Interest

3,4-Fused pyrrolocoumarins, synthetically prepared or naturally occurring, possess interesting biological properties. In this review, the synthetic strategies for the synthesis of the title compounds are presented along with their biological activities. Two routes are followed for that synthesis. In one, the pyrrole ring is formed from coumarin derivatives, such as aminocoumarins or other coumarins. In the other approach, the pyranone moiety is built from an existing pyrrole derivative or through the simultaneous formation of coumarin and pyrrole frameworks. The above syntheses are achieved via 1,3-dipolar cycloaddition reactions, Michael reaction, aza-Claisen rearrangement reactions, multi-component reactions (MCR), as well as metal-catalyzed reactions. Pyrrolocoumarins present cytotoxic, antifungal, antibacterial, α-glucosidase inhibition, antioxidant, lipoxygenase (LOX) inhibition, and fluorescent activities, as well as benzodiazepine receptor ability.

Methoxyfuranocoumarins of Natural Origin-Updating Biological Activity Research and Searching for New Directions-A Review

Plant secondary metabolites, including furanocoumarins, have attracted attention for decades as active molecules with therapeutic potential, especially those occurring in a limited number of species as evolutionarily specific and chemotaxonomically important. The most famous methoxyfuranocoumarins (MFCs), bergapten, xanthotoxin, isopimpinellin, phellopterin, byakangelicol, byakangelicin, isobergapten, pimpinellin, sphondin, as well as rare ones such as peucedanin and 8-methoxypeucedanin, apaensin, cnidilin, moellendorffiline and dahuribiethrins, have recently been investigated for their various biological activities. The α-glucosidase inhibitory activity and antioxidant potential of moellendorffiline, the antiproliferative and proapoptotic properties of non-UV-activated bergapten and xanthotoxin, the effect of MFC on the activity of tyrosinase, acetyl- and butylcholinesterase, and the role of these compounds as adjuvants in anticancer and antibacterial tests have been confirmed. The anticonvulsant effects of halfordin, the antidepressant effects of xanthotoxin, and the antiadipogenic, neuroprotective, anti-amyloid-β, and anti-inflammatory (via increasing SIRT 1 protein expression) properties of phellopterin, as well as the activity of sphondin against hepatitis B virus, have also attracted interest. It is worth paying attention to the agonistic effect of xanthotoxin on bitter taste receptors (TAS2Rs) on cardiomyocytes, which may be important in the future treatment of tachycardia, as well as the significant anti-inflammatory activity of dahuribiethrins. It should be emphasized that MFCs, although in many cases isolated for the first time many years ago, are still of great interest as bioactive molecules. The aim of this review is to highlight key recent developments in the study of the diverse biological activities of MFCs and attempt to highlight promising directions for their further research. Where possible, descriptions of the mechanisms of action of MFC are provided, which is related to the constantly discovered therapeutic potential of these molecules. The review covers the results of experiments from the last ten years (2014-2023) conducted on isolated natural cMFCs and includes the activity of molecules that have not been activated by UV rays.

Phytochemical profiling, in vitro biological activities, and in silico (molecular docking and absorption, distribution, metabolism, excretion, toxicity) studies of Polygonum cognatum Meissn

Polygonum cognatum Meissn, a perennial herbaceous belonging to the Polygonaceae family, is an aromatic plant. High-performance liquid chromatography/diode array detector method was developed and validated for the phytochemical analysis of the plant. Also, various methods were used to investigate the antioxidant, antimicrobial, and cytotoxic activities of the methanolic extracts. Antioxidant activities were researched by 2,2'-diphenyl-1-picrylhydrazyl and cupric reducing antioxidant capacity methods. Among the tested standard microbial strains, Candida albicans was found to be more sensitive with a 24.60 ± 0.55 mm inhibition zone according to the diffusion tests. In the microdilution tests, the minimum inhibitory concentration and minimum bactericidal/fungicidal concentration values were 4.75 and ≥ 4.75 mg/mL, respectively, for all tested pathogens. Human colon carcinoma cells were used to investigate cytotoxicity by using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide analysis (IC50  = 2891 μg/mL for Plant A, IC50  = 3291 μg/mL for Plant B). Molecular docking and absorption, distribution, metabolism, excretion, and toxicity analysis were used to explain inhibition mechanisms of major phenolic compounds of plants against Tankyrase 1, Tankyrase 2 enzymes, and deoxyribonucleic acid gyrase subunit B and found compatible with experimental results.

Antidepressant effects of coumarins and their derivatives: A critical analysis of research advances

Coumarins and their derivatives are non-flavonoids polyphenols with diverse pharmacological activities including anti-depressant effects. This study systematically examines the antidepressant effects of coumarins and their derivatives in relation to time series of research progress in the pharmacological pathways, association with other diseases, toxicity and bibliometric analysis. The review was approached using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) coupled with R package involving Biblioshiny, a web interface for Bibliometrix analysis and VOSviewer software analytic tools. Literature searches were conducted in Scopus, Web of Science, and PubMed from the inception through January 21, 2023. Coumarins, depression, coumarin derivatives and treatment were the main search terms used which resulted in the inclusion of 46 eligible publications. Scopoletin, psoralen, 7-hydroxycoumarin, meranzin hydrate, osthole, esculetin/umbelliferone were the most studied coumarins with antidepressant effects. Coumarins and their derivatives exerted antidepressant effects with a stronger affinity for monoamine oxidase-B (MAO-B) inhibition and, their inhibitory effect via neurotransmitter pathway on MAO is well-studied. However, epigenetic modification, neuroendocrine, neurotrophic pathways are understudied. Recent research focuses on their antidepressant effects which targeted cytokines and fibromyalgia. There is a link between the gut microbiome, the brain, and depression; meranzin hydrate exerts an antidepressant activity by remodelling the gastrointestinal system. We established that empirical data on some coumarins and their derivatives to support their antidepressant effects are limited. Likewise, the safe dose range for several coumarins and their derivatives is yet to be fully determined.

3-(Bromoacetyl) coumarin is a potential therapeutic agent against neonatal sepsis-associated Pseudomonas extremorientalis

Neonatal sepsis is a severe bacterial infection that can lead to life-threatening complications in newborns. Pseudomonas extremorientalis is a Gram-negative bacterium and these Gram-negative organisms have been identified as a major cause of neonatal sepsis. The virulence factors produced by this bacterium play a crucial role in its pathogenicity. Therefore, targeting these virulence factors could be a potential strategy to treat neonatal sepsis caused by P. extremorientalis. In this study, we investigated the efficacy of 3-(bromoacetyl) coumarin (3-BC) in reducing the virulence factors of P. extremorientalis strains isolated from neonatal sepsis. Our results showed that 3-BC effectively reduced the production of various virulence factors, including protease, elastase, siderophore, and exopolysaccharide in these strains. Furthermore, at a concentration of 125 µg/ml, 3-BC also inhibited the biofilm formation ability of these strains in combination with ciprofloxacin. It was discovered that 3-BC was functionally effective in protecting C. elegans against bacterial infection. Moreover, the in vitro and in vivo outcomes were strongly correlated with docking studies of various activator proteins. Overall, our findings suggest that 3-BC could be a potential therapeutic agent for the treatment of neonatal sepsis caused by P. extremorientalis. Further studies are needed to explore the mechanism of action of 3-BC and its potential use in clinical settings.

6-Methylcoumarin Promotes Melanogenesis through the PKA/CREB, MAPK, AKT/PI3K, and GSK3β/β-Catenin Signaling Pathways

We investigated the effects of four coumarin derivatives, namely, 6-methylcoumarin, 7-methylcoumarin, 4-hydroxy-6-methylcoumarin, and 4-hydroxy-7-methylcoumarin, which have similar structures on melanogenesis in a murine melanoma cell line from a C57BL/6J mouse called B16F10. Our results showed that only 6-methylcoumarin significantly increased the melanin synthesis in a concentration-dependent manner. In addition, the tyrosinase, TRP-1, TRP-2, and MITF protein levels were found to significantly increase in response to 6-methylcoumarin in a concentration-dependent manner. To elucidate the molecular mechanism whereby 6-methylcoumarin-induced melanogenesis influences the melanogenesis-related protein expression and melanogenesis-regulating protein activation, we further assessed the B16F10 cells. The inhibition of the ERK, Akt, and CREB phosphorylation, and conversely, the increased p38, JNK, and PKA phosphorylation activated the melanin synthesis via MITF upregulation, which ultimately led to increased melanin synthesis. Accordingly, 6-methylcoumarin increased the p38, JNK, and PKA phosphorylation in the B16F10 cells, whereas it decreased the phosphorylated ERK, Akt, and CREB expressions. In addition, the 6-methylcoumarin activated GSK3β and β-catenin phosphorylation and reduced the β-catenin protein level. These results suggest that 6-methylcoumarin stimulates melanogenesis through the GSK3β/β-catenin signal pathway, thereby affecting the pigmentation process. Finally, we tested the safety of 6-methylcoumarin for topical applications using a primary human skin irritation test on the normal skin of 31 healthy volunteers. We found that 6-methylcoumarin did not cause any adverse effects at concentrations of 125 and 250 μM. Our findings indicate that 6-methylcoumarin may be an effective pigmentation stimulator for use in cosmetics and the medical treatment of photoprotection and hypopigmentation disorders.

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.

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.

Cytogenotoxicity assessment of 3-(3,4-dihydroxyphenyl)-7,8-dihydroxycoumarin on HepG2/C3A cells and leukocytes

3-(3,4-Dihydroxyphenyl)-7,8-dihydroxycoumarin is a newly synthesized coumarin derivative with a potent antioxidant effect. The aim of the present study is to investigate the safety of this compound, determining the in vitro cytotoxic and genotoxic in human peripheral blood mononuclear cells (PBMC) and in HepG2/C3A cells. Cell viability has been investigated by the trypan blue staining test and MTT assay and the genotoxicity by the comet assay and micronucleus test, using concentrations between 0.01 and 10 μg/ml. The compound proved to be noncytotoxic in both cell lines, at all tested concentrations, protecting the cells from the DNA damage. In addition, this molecule does not show clastogenic/aneugenic effects when performing the micronucleus test with cytokinesis blockade. Based on the obtained data, and the conditions of the experiments, we can conclude that the 3-(3,4-dihydroxyphenyl)-7,8-dihydroxycoumarin is a safe molecule up to a concentration of 10 μg/ml, which encourages further studies aiming to explore its potential as a drug candidate.

Selective Syntheses of Coumarin and Benzofuran Derivatives Using Phenols and α-Methoxy-β-ketoesters

Selective syntheses of coumarin and benzofuran derivatives were achieved via HClO4-mediated intermolecular annulation using phenols and α-methoxy-β-ketoesters. Coumarins are formed under dehydrated conditions, whereas benzofurans are formed in the presence of water. In the synthetic process of benzofurans, α-methoxy-β-ketoesters are converted into α-methoxyacetophenones, and the methoxy group is an important element in the intermolecular annulation.

Coumarins of Lovage Roots (Levisticum officinale W.D.J.Koch): LC-MS Profile, Quantification, and Stability during Postharvest Storage

Lovage (Levisticum officinale W.D.J. Koch) is a known aromatic apiaceous species that is widely used as a culinary and medicinal plant. Traditionally, more scientific attention has been paid to lovage volatiles, while other groups of compounds have been underutilized. In this study, metabolites of fresh lovage roots were investigated by liquid chromatography-mass spectrometry, and 25 compounds were identified, including coumarins as basic components and minor hydroxycinnamates; most were detected for the first time in the plant. Four major coumarins (including apterin, xanthotoxin, isopimpinellin, and pimpinellin) were successfully separated by a validated HPLC-PDA method, and the fresh roots of seven lovage cultivars as well as the dry roots of commercial lovage were quantified. The coumarin content deviation was 1.7-2.9 mg/g in the fresh roots and 15-24 mg/g in the dry roots. A variation in the coumarin level was found during storage of the fresh lovage roots at chill and room temperatures, while storage of the dried roots at room temperature showed the lowest loss of target compounds. This new information about the metabolites of lovage indicates the prospects of the plant roots as a source of dietary coumarins.

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.

Nutritional Composition of Tonka Bean (Dipteryx odorata) and Its Application as an Elder-Friendly Food with Gelling Agent

(1) Background: The purpose of this study was to compare the nutritional characteristics of Tonka beans according to the cooking method and to prove the feasibility of application as an elder-friendly food. (2) Methods: After analyzing the nutritive components, antioxidant activity, and anti-diabetic activity of raw, boiled, and roasted Tonka beans, custards, to which roasted Tonka beans were added, were prepared using a gelling agent to meet the KS viscosity standards (≤1500 mPa.s). (3) Results: The cooking methods decreased the nutritive factors in Tonka beans. However, while boiling caused significant losses, roasting led to minor losses. However, because the elderly should avoid eating uncooked foods for safety reasons, semi-solid elder-friendly food was manufactured with roasted Tonka beans, which caused minor losses compared to boiling. The concentration of each gelling agent satisfying the KS viscosity was less than 0.745% of locust bean gum, 0.734% of κ-carrageenan, and 1.094% of agar. (4) Conclusions: Roasted Tonka beans are suitable for use as an elder-friendly food for the health and safety of the elderly, and it will be possible to promote balanced food intake through the use of gelling agents for the elderly who have difficulty swallowing.

Phytochemicals as Regulators of Tumor Glycolysis and Hypoxia Signaling Pathways: Evidence from In Vitro Studies

The full understanding of the complex nature of cancer still faces many challenges, as cancers arise not as a result of a single target disruption but rather involving successive genetic and epigenetic alterations leading to multiple altered metabolic pathways. In this light, the need for a multitargeted, safe and effective therapy becomes essential. Substantial experimental evidence upholds the potential of plant-derived compounds to interfere in several important pathways, such as tumor glycolysis and the upstream regulating mechanisms of hypoxia. Herein, we present a comprehensive overview of the natural compounds which demonstrated, in vitro studies, an effective anticancer activity by affecting key regulators of the glycolytic pathway such as glucose transporters, hexokinases, phosphofructokinase, pyruvate kinase or lactate dehydrogenase. Moreover, we assessed how phytochemicals could interfere in HIF-1 synthesis, stabilization, accumulation, and transactivation, emphasizing PI3K/Akt/mTOR and MAPK/ERK pathways as important signaling cascades in HIF-1 activation. Special consideration was given to cell culture-based metabolomics as one of the most sensitive, accurate, and comprising approaches for understanding the response of cancer cell metabolome to phytochemicals.

Artemisia gmelinii Attenuates Lung Inflammation by Suppressing the NF-κB/MAPK Pathway

Cigarette smoke (CS) is the main cause of chronic obstructive pulmonary disease (COPD), and continuous CS exposure causes lung inflammation and deterioration. To investigate the protective effects of Artemisia gmelinii against lung inflammation in this study, cigarette smoke extract (CSE)/lipopolysaccharide (LPS)-treated alveolar macrophages (AMs) and mice stimulated with CSE/porcine pancreas elastase (PPE) were used. Artemisia gmelinii ethanol extract (AGE) was effective in decreasing the levels of cytokines, chemokine, inducible nitric oxide synthase, and cyclooxygenase-2 by inhibiting mitogen-activated protein (MAP) kinases/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway in AMs. Additionally, oral administration of AGE suppressed inflammatory cells’ infiltration and secretion of inflammatory cytokines, chemokines, matrix metallopeptidase 9, and neutrophil extracellular traps in bronchoalveolar lavage fluid from the COPD model. Moreover, the obstruction of small airways, the destruction of the lung parenchyma, and expression of IL-6, TNF-α, IL-1β, and MIP-2 were suppressed by inhibiting NF-κB activation in the lung tissues of the AGE group. These effects are associated with scopolin, chlorogenic acid, hyperoside, 3,4-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, and 4,5-di-O-caffeoylquinic acid, which are the main components of AGE. These data demonstrate the mitigation effect of AGE on lung inflammation via inhibition of MAPK and NF-κB pathways, suggesting that AGE may be instrumental in improving respiratory and lung health.