Chemical Constituents from the Roots of Angelica reflexa That Improve Glucose-Stimulated Insulin Secretion by Regulating Pancreatic β-Cell Metabolism

Systematic review of natural coumarins in plants (2019-2024): Chemical structures and pharmacological activities

Coumarins constitute one of the most substantial classes of secondary metabolites, characterised by a fundamental α-benzopyranone skeleton, which serves as an overarching nomenclature for o-hydroxycinnamyl lactone moieties. These chemical constituents are widely distributed in various plant species. Based on the nature and loci of their substituents, these compounds can be further classified into simple coumarins, furanocoumarins, pyranocoumarins, isocoumarins, biscoumarins and other coumarins. Contemporary pharmacological research has revealed that coumarins exhibit a spectrum of properties, including antibacterial, antioxidant, anticancer, anti-inflammatory and hypoglycaemic activities. Owing to their diverse of structures and pharmacological actions, coumarins are widely used in cuisine, cosmetics and pharmaceutical industries. An extensive body of scholarly literature has been produced in this domain, although a notable paucity in the compilation and updating of references has been identified since 2019. Herein, the chemical structures and pharmacological activities of coumarins reported for the first time between 2019 and 2024 were systematically summarised. In total, 220 scholarly articles involving 574 coumarins reported for the first time in plants were included in this review. In addition, the biosynthetic pathways of some common types of coumarins (simple coumarins, furanocoumarins, and pyranocoumarins) are also preliminarily summarised in this paper. Meticulously analyzing and synthesising the published literature will lay a solid foundation for further investigation and extensive utilisation of coumarin derivatives.

Trifolirhizin: A Phytochemical with Multiple Pharmacological Properties

Trifolirhizin is an important flavonoid glycoside reported from the roots of medicinal plants such as Astragalus membranaceus, Sophora tonkinensis, Ononis vaginalis, Euchresta formosana, Sophora Subprostrate, Ononis spinose, and Sophora flavescens. It is considered one of the important constituents responsible for the various medicinal properties of these medicinal plants. Studies have revealed the multiple pharmacological properties of trifolirhizin: anti-inflammatory, antioxidant, antibacterial, anti-ulcerative colitis, antiasthma, hepatoprotective, osteogenic, skin-whitening, wound-healing, and anticancer (against various types of cancers). Mechanistic studies of trifolirhizin showed that it could act on important target genes and pathways such as the NF-κB-MAPK, EGFR-MAPK, AMPK/mTOR, and PI3K/Akt signaling pathways. These pathways are also implicated in various other diseases, suggesting the potential of trifolirhizin in therapeutic applications. Initial pharmacokinetic studies support the therapeutic candidature of trifolirhizin and provide the initial track that may be pursued for its development. Still, a compilation of pharmacological activities and target pathways of trifolirhizin is missing in the literature. This review uniquely compiles the pharmacological properties and mechanistic insights of trifolirhizin, addressing critical gaps in its therapeutic development and proposing strategies for future research.

Biological Properties and Phytochemicals of Multipurpose Tree Plant Hagenia abyssinica

Hagenia abyssinica (HA) is a monotypic tree species used as traditional medicine against various diseases and conditions in African countries. HA is also a multipurpose plant used for furniture, fuel wood, soil fertility management, and rainwater conservation, along with medicinal usage. In different in vitro, in vivo, ex vivo, and human studies, the potential of HA for different pharmacological properties, including anti-parasite, antibacterial, antifungal, antispasmodic, anticancer, anti-diabetes, antidiarrheal, wound healing, antioxidant, and anti-inflammatory activities were observed. Antioxidant and anti-inflammation properties of HA may be the primary reason for the multi-pharmacological activities of HA. Initial toxicity studies and the presence of various phytochemicals, especially flavonoids, also support the therapeutic potential of HA. The diverse medicinal properties of the plant have different challenges to overcome for its development. Limited studies to decipher the molecular mechanism behind the pharmacological activity restrict the utilization of the complete potential of HA as therapeutics. Still, the compilation of phytochemical, pharmacological activities, and target pathways of HA is missing in the literature. The current review not only compiles the pharmacological activities and phytochemicals but also highlights the gaps and proposes the future direction to develop HA as a candidate against important diseases.

Pharmacological and phytochemical insights on the pancreatic β-cell modulation by Angelica L. roots

ETHNOPHARMACOLOGICAL RELEVANCE

Angelica roots are a significant source of traditional medicines for various cultures around the northern hemisphere, from indigenous communities in North America to Japan. Among its many applications, the roots are used to treat type 2 diabetes mellitus; however, this application is not mentioned often. Ethnopharmacological studies have reported the use of A. japonica var. hirsutiflora, A. furcijuga, A. shikokiana, and A. keiskei to treat diabetes symptoms, and further reports have demonstrated the three angelica roots, i.e., A. japonica var. hirsutiflora, A. reflexa, and A. dahurica, exhibit insulin secretagogue activity.

AIM OF THE STUDY

This study aimed to phytochemically characterize and compare angelica roots monographed in the European Pharmacopeia 11th, isolate major plant metabolites, and assess extracts and isolates' capability to modulate pancreatic β-cell function.

MATERIALS AND METHODS

Root extracts of Angelica archangelica, Angelica dahurica, Angelica biserrata, and Angelica sinensis were phytochemically profiled using liquid chromatography method coupled with mass spectrometry. Based on this analysis, simple and furanocoumarins were isolated using chromatography techniques. Extracts (1.6-50 μg/mL) and isolated compounds (5-40 μmol/L) were studied for their ability to modulate insulin secretion in the rat insulinoma INS-1 pancreatic β-cell model. Insulin was quantified by the homogeneous time-resolved fluorescence method.

RESULTS

Forty-one secondary metabolites, mostly coumarins, were identified in angelica root extracts. A. archangelica, A. dahurica, and A. biserrata root extracts at concentration of 12.5-50 μg/mL potentiated glucose-induced insulin secretion, which correlated with their high coumarin content. Subsequently, 23 coumarins were isolated from these roots and screened using the same protocol. Coumarins substituted with the isoprenyl group were found to be responsible for the extracts' insulinotropic effect.

CONCLUSIONS

Insulinotropic effects of three pharmacopeial angelica roots were found, the metabolite profiles and pharmacological activities of the roots were correlated, and key structures responsible for the modulation of pancreatic β-cell function were identified. These findings may have implications for the traditional use of angelica roots in treating diabetes. Active plant metabolites may also become lead structures in the search for new antidiabetic treatments.

Anti-obesity and anti-diabetic bioactive peptides: A comprehensive review of their sources, properties, and techno-functional challenges

The scourge of obesity arising from obesogens and poor dieting still ravages our planet as half of the global population may be overweight and obese by 2035. This metabolic disorder is intertwined with type 2 diabetes (T2D), both of which warrant alternative therapeutic options other than clinically approved drugs like orlistat with their tendency of abuse and side effects. In this review, we comprehensively describe the global obesity problem and its connection to T2D. Obesity, overconsumption of fats, the mechanism of fat digestion, obesogenic gut microbiota, inhibition of fat digestion, and natural anti-obesity compounds are discussed. Similar discussions are made for diabetes with regard to glucose regulation, the diabetic gut microbiota, and insulinotropic compounds. The sources and production of anti-obesity bioactive peptides (AOBPs) and anti-diabetic bioactive peptides (ADBPs) are also described while explaining their structure-function relationships, gastrointestinal behaviors, and action mechanisms. Finally, the techno-functional applications of AOBPs and ADBPs are highlighted.

Chemical Relationship among Genetically Authenticated Medicinal Species of Genus Angelica

The genus Angelica comprises various species utilized for diverse medicinal purposes, with differences attributed to the varying levels or types of inherent chemical components in each species. This study employed DNA barcode analysis and HPLC analysis to genetically authenticate and chemically classify eight medicinal Angelica species (n = 106) as well as two non-medicinal species (n = 14) that have been misused. Nucleotide sequence analysis of the nuclear internal transcribed spacer (ITS) region revealed differences ranging from 11 to 117 bp, while psbA-trnH showed variances of 3 to 95 bp, respectively. Phylogenetic analysis grouped all samples except Angelica sinensis into the same cluster, with some counterfeits forming separate clusters. Verification using the NCBI database confirmed the feasibility of species identification. For chemical identification, a robust quantitative HPLC analysis method was developed for 46 marker compounds. Subsequently, two A. reflexa-specific and seven A. biserrata-specific marker compounds were identified, alongside non-specific markers. Moreover, chemometric clustering analysis reflecting differences in chemical content between species revealed that most samples formed distinct clusters according to the plant species. However, some samples formed mixed clusters containing different species. These findings offer crucial insights for the standardization and quality control of medicinal Angelica species.

Anti-Obesity and Anti-Diabetic Effects of Ostericum koreanum (Ganghwal) Extract

"Ganghwal" is a widely used herbal medicine in Republic of Korea, but it has not been reported as a treatment strategy for obesity and diabetes within adipocytes. In this study, we determined that Ostericum koreanum extract (OKE) exerts an anti-obesity effect by inhibiting adipogenesis and an anti-diabetic effect by increasing the expression of genes related to glucose uptake in adipocytes and inhibiting α-glucosidase activity. 3T3-L1 preadipocytes were differentiated for 8 days in methylisobutylxanthine, dexamethasone, and insulin medium, and the effect of OKE was confirmed by the addition of 50 and 100 µg/mL of OKE during the differentiation process. This resulted in a reduction in lipid accumulation and the expression of PPARγ (Peroxisome proliferator-activated receptor γ) and C/EBPα (CCAAT enhancer binding protein α). Significant activation of AMPK (AMP-activated protein kinase), increased expression of GLUT4 (Glucose Transporter Type 4), and inhibition of α-glucosidase activity were also observed. These findings provide the basis for the anti-obesity and anti-diabetic effects of OKE. In addition, OKE has a significant antioxidant effect. This study presents OKE as a potential natural product-derived material for the treatment of patients with metabolic diseases such as obesity- and obesity-induced diabetes.

The Bioactivity and Phytochemicals of Muscari comosum (Leopoldia comosa), a Plant of Multiple Pharmacological Activities

Leopoldia comosa (LC), popularly known as Muscari comosum, spontaneously grows in the Mediterranean region and its bulbs are used as a vegetable. Traditionally, they are also used to treat various diseases and conditions, which has inspired the study of the pharmacological activities of different parts of LC. These studies revealed the numerous biological properties of LC including antioxidant, anti-inflammatory, anti-diabetes, anti-obesity, anti-cancer, anti-Alzheimer's disease, antibacterial, and immune stimulant. High antioxidant activity compared to other non-cultivated plants, and the potential role of antioxidant activity in other reported activities make LC an excellent candidate to be developed as an antioxidant plant against important associated diseases. The presence of a diverse class of phytochemicals (n = 85), especially flavonoids and homoisoflavones, in LC, also imparts significance to the nutraceutical candidature of the plant. However, limited animal studies and the lack of a directional approach have limited the further design of effective clinical studies for the development of LC. The current study is the first attempt to comprehensively compile information regarding the phytochemicals and pharmacological activities of LC, emphasize the targets/markers targeted by LC, important in other activities, and also highlight the current gaps and propose possible bridges for the development of LC as a therapeutic and/or supplement against important diseases.