Osthole, a potential antidiabetic agent, alleviates hyperglycemia in db/db mice

Tumor-Specific Nano-Herb Delivery System with High L-Arginine Loading for Synergistic Chemo and Gas Therapy against Cervical Cancer

Cancer metastasis poses significant challenges in current clinical therapy. Osthole (OST) has demonstrated efficacy in treating cervical cancer and inhibiting metastasis. Despite these positive results, its limited solubility, poor oral absorption, low bioavailability, and photosensitivity hinder its clinical application. To address this limitation, a glutathione (GSH)-responded nano-herb delivery system (HA/MOS@OST&L-Arg nanoparticles, HMOA NPs) is devised for the targeted delivery of OST with cascade-activatable nitric oxide (NO) release. The HMOA NPs system is engineered utilizing enhanced permeability and retention (EPR) effects and active targeting mediated by hyaluronic acid (HA) binding to glycoprotein CD44. The cargoes, including OST and L-Arginine (L-Arg), are released rapidly due to the degradation of GSH-responsive mesoporous organic silica (MOS). Then abundant reactive oxygen species (ROS) are produced from OST in the presence of high concentrations of NAD(P)H quinone oxidoreductase 1 (NQO1), resulting in the generation of NO and subsequently highly toxic peroxynitrite (ONOO-) by catalyzing guanidine groups of L-Arg. These ROS, NO, and ONOO- molecules have a direct impact on mitochondrial function by reducing mitochondrial membrane potential and inhibiting adenosine triphosphate (ATP) production, thereby promoting increased apoptosis and inhibiting metastasis. Overall, the results indicated that HMOA NPs has great potential as a promising alternative for the clinical treatment of cervical cancer.

Role of microglia in diabetic neuropathic pain

Approximately one-third of the patients with diabetes worldwide suffer from neuropathic pain, mainly categorized by spontaneous and stimulus-induced pain. Microglia are a class of immune effector cells residing in the central nervous system and play a pivotal role in diabetic neuropathic pain (DNP). Microglia specifically respond to hyperglycemia along with inflammatory cytokines and adenosine triphosphate produced during hyperglycemic damage to nerve fibers. Because of the presence of multiple receptors on the microglial surface, microglia are dynamically and highly responsive to their immediate environment. Following peripheral sensitization caused by hyperglycemia, microglia are affected by the cascade of inflammatory factors and other substances and respond accordingly, resulting in a change in their functional state for DNP pathogenesis. Inhibition of receptors such as P2X reporters, reducing cytokine expression levels in the microglial reactivity mechanisms, and inhibiting their intracellular signaling pathways can effectively alleviate DNP. A variety of drugs attenuate DNP by inhibiting the aforementioned processes induced by microglial reactivity. In this review, we summarize the pathological mechanisms by which microglia promote and maintain DNP, the drugs and therapeutic techniques available, and the latest advances in this field.

Oral administration of osthole mitigates maladaptive behaviors through PPARα activation in mice subjected to repeated social defeat stress

Psychological stress induces neuroinflammatory responses, which are associated with the pathogenesis of various psychiatric disorders, such as posttraumatic stress disorder and anxiety. Osthole-a natural coumarin isolated from the seeds of the Chinese herb Cnidium monnieri-exerts anti-inflammatory and antioxidative effects on the central nervous system. However, the therapeutic benefits of osthole against psychiatric disorders remain largely unknown. We previously demonstrated that mice subjected to repeated social defeat stress (RSDS) in the presence of aggressor mice exhibited symptoms of posttraumatic stress disorder, such as social avoidance and anxiety-like behaviors. In this study, we investigated the therapeutic effects of osthole and the underlying molecular mechanisms. Osthole exerted therapeutic effects on cognitive behaviors, mitigating anxiety-like behaviors and social avoidance in a mouse model of RSDS. The anti-inflammatory response induced by the oral administration of osthole was strengthened through the upregulation of heme oxygenase-1 expression. The expression of PPARα was inhibited in mice subjected to RSDS. Nonetheless, osthole treatment reversed the inhibition of PPARα expression. We identified a positive correlation between heme oxygenase-1 expression and PPARα expression in osthole-treated mice. In conclusion, osthole has potential as a Chinese herbal medicine for anxiety disorders. When designing novel drugs for psychiatric disorders, researchers should consider targeting the activation of PPARα.

Osthole ameliorates early diabetic kidney damage by suppressing oxidative stress, inflammation and inhibiting TGF-β1/Smads signaling pathway

BACKGROUND

Osthole is a natural active ingredient extracted from the traditional Chinese medicine Cnidium monnieri. It has been demonstrated to have anti-inflammatory, anti-fibrotic, and anti-hyperglycemic properties. However, its effect on diabetic kidney disease (DKD) remains uncertain. This study aims to assess the preventive and therapeutic effects of osthole on DKD and investigate its underlying mechanisms.

METHODS

A streptozotocin/high-fat and high-sucrose diet induced Type 2 diabetic rat model was established. Metformin served as the positive drug control. Diabetic rats were treated with metformin or three different doses of osthole for 8 weeks. Throughout the treatment period, the progression of DKD was assessed by monitoring increases in urinary protein, serum creatinine, urea nitrogen, and uric acid, along with scrutinizing kidney pathology. Enzyme-linked immunosorbent assay (ELISA) was employed to detect inflammatory factors and oxidative stress levels. At the same time, immunohistochemical staining was utilized to evaluate changes in alpha-smooth muscle actin, fibronectin, E-cadherin, and apoptosis. The alterations in TGF-β1/Smads signaling pathway were ascertained through western blot and immunofluorescence. Furthermore, we constructed a high glucose-stimulated HBZY-1 cells model to uncover its molecular protective mechanism.

RESULTS

Osthole significantly reduced fasting blood glucose, insulin resistance, serum creatinine, uric acid, blood urea nitrogen, urinary protein excretion, and glomerular mesangial matrix deposition in diabetic rats. Additionally, significant improvements were observed in inflammation, oxidative stress, apoptosis, and fibrosis levels. The increase of ROS, apoptosis and hypertrophy in HBZY-1 cells induced by high glucose was reduced by osthole. Immunofluorescence and western blot results demonstrated that osthole down-regulated the TGF-β1/Smads signaling pathway and related protein expression.

CONCLUSION

Our findings indicate that osthole exhibits potential preventive and therapeutic effects on DKD. It deserves further investigation as a promising drug for preventing and treating DKD.

Vasorelaxant and Blood Pressure-Lowering Effects of Cnidium monnieri Fruit Ethanol Extract in Sprague Dawley and Spontaneously Hypertensive Rats

Cnidium monnieri (L.) Cusson, a member of the Apiaceae family, is rich in coumarins, such as imperatorin and osthole. Cnidium monnieri fruit (CM) has a broad range of therapeutic potential that can be used in anti-bacterial, anti-cancer, and sexual dysfunction treatments. However, its efficacy in lowering blood pressure through vasodilation remains unknown. This study aimed to assess the potential therapeutic effect of CM 50% ethanol extract (CME) on hypertension and the mechanism of its vasorelaxant effect. CME (1-30 µg/mL) showed a concentration-dependent vasorelaxation on constricted aortic rings in Sprague Dawley rats induced by phenylephrine via an endothelium-independent mechanism. The vasorelaxant effect of CME was inhibited by blockers of voltage-dependent and Ca2+-activated K+ channels. Additionally, CME inhibited the vascular contraction induced by angiotensin II and CaCl2. The main active compounds of CM, i.e., imperatorin (3-300 µM) and osthole (1-100 µM), showed a concentration-dependent vasorelaxation effect, with half-maximal effective concentration values of 9.14 ± 0.06 and 5.98 ± 0.06 µM, respectively. Orally administered CME significantly reduced the blood pressure of spontaneously hypertensive rats. Our research shows that CME is a promising treatment option for hypertension. However, further studies are required to fully elucidate its therapeutic potential.

Vitisin B, a resveratrol tetramer from Vitis thunbergii var. taiwaniana, ameliorates impaired glucose regulations in nicotinamide/streptozotocin-induced type 2 diabetic mice

Background and aim

In Taiwan, Vitis thunbergii var. taiwaniana (VTT) is used in traditional medicine and as a local tea. VTT rich in resveratrol and resveratrol oligomers have been reported to exhibit anti-obesity and anti-hypertensive activities in animal models; however, no studies have investigated type 2 diabetes mellitus (T2DM) treatments. This study aimed to investigate the anti-T2DM effects of resveratrol tetramers isolated from the VTT in nicotinamide/streptozotocin (STZ)-induced Institute of Cancer Research (ICR) mice.

Experimental procedure

The oral glucose tolerance test (OGTT) was used to imitate postprandial blood glucose (BG) regulations in mice by pre-treatment with VTT extracts, resveratrol tetramers of vitisin A, vitisin B, and hopeaphenol 30 min before glucose loads. Vitisin B (50 mg/kg) was administered to treat T2DM-ICR mice once daily for 28 days to investigate its hypoglycemic activity.

Results and conclusion

Mice pre-treated with VTT-S-95EE, or vitisin B (100 mg/kg) 30-min before glucose loading showed significant reductions (P < 0.001) in the area under the curve at 120-min (BG-AUC0-120) than those without pre-treatment with VTT-S-95 E E or vitisin B. Vitisin B-treated T2DM mice showed hypoglycemic activities via a reduction in plasma dipeptidyl peptidase (DPP)-IV activities to maintain insulin actions and differed significantly than those of untreated T2DM mice (P < 0.05), and also reduced BG-AUC0-120 and insulin-AUC0-120 in the OGTT.These in vivo results showed that VTT containing vitisin B would be beneficial for developing nutraceuticals and/or functional foods for glycemic control in patients with T2DM, which should be investigated further.

Dietary regulation of peroxisome proliferator-activated receptors in metabolic syndrome

BACKGROUND

Peroxisome proliferator-activated receptors (PPARs) are a class of ligand-activated nuclear transcription factors, members of the type nuclear receptor superfamily, with three subtypes, namely PPARα, PPARβ/δ, and PPARγ, which play a key role in the metabolic syndrome. In the past decades, a large number of studies have shown that natural products can act by regulating metabolic pathways mediated by PPARs.

PURPOSE

This work summarizes the physiological importance and clinical significance of PPARs and reviews the experimental evidence that natural products mediate metabolic syndrome via PPARs.

METHODS

This study reviews relevant literature on clinical trials, epidemiology, animals, and cell cultures published in NCBI PubMed, Scopus, Web of Science, Google Scholar, and other databases from 2001 to October 2022. Search keywords were "natural product" OR "botanical" OR "phytochemical" AND "PPAR" as well as free text words.

RESULTS

The modulatory involvement of PPARs in the metabolic syndrome has been supported by prior research. It has been observed that many natural products can treat metabolic syndrome by altering PPARs. The majority of currently described natural compounds are mild PPAR-selective agonists with therapeutic effects that are equivalent to synthetic medicines but less harmful adverse effects.

CONCLUSION

PPAR agonists can be combined with natural products to treat and prevent metabolic syndrome. Further human investigations are required because it is unknown how natural products cause harm and how they might have negative impacts.

Therapeutic Effects of Coumarins with Different Substitution Patterns

The use of derivatives of natural and synthetic origin has gained attention because of their therapeutic effects against human diseases. Coumarins are one of the most common organic molecules and are used in medicine for their pharmacological and biological effects, such as anti-inflammatory, anticoagulant, antihypertensive, anticonvulsant, antioxidant, antimicrobial, and neuroprotective, among others. In addition, coumarin derivates can modulate signaling pathways that impact several cell processes. The objective of this review is to provide a narrative overview of the use of coumarin-derived compounds as potential therapeutic agents, as it has been shown that substituents on the basic core of coumarin have therapeutic effects against several human diseases and types of cancer, including breast, lung, colorectal, liver, and kidney cancer. In published studies, molecular docking has represented a powerful tool to evaluate and explain how these compounds selectively bind to proteins involved in various cellular processes, leading to specific interactions with a beneficial impact on human health. We also included studies that evaluated molecular interactions to identify potential biological targets with beneficial effects against human diseases.

Osthole Antagonizes Microglial Activation in an NRF2-Dependent Manner

Microglia are neuroglia in the brain with an innate immune function and participate in the progress of neurodegenerative diseases. Osthole (OST) is a coumarin derivative extracted from Cnidium monnieri and bears a microglia-antagonizing ability. However, the underlying mechanism of the antagonism is not clear. The lipopolysaccharides-induced microglial BV2 cell line and amyloid-overexpressing fruit fly were used as models to study OST treatment. We found that OST treatment is sufficient to evoke NRF2 cascade under an LPS-induced inflammatory environment, and silencing NRF2 is sufficient to abolish the process. Moreover, we found that OST is sufficient to antagonize microglial activation in both LPS-induced BV2 cells and Aβ-overexpressing fruit flies, and silencing NRF2 abolishes OST's antagonism. Furthermore, OST treatment rescued survival, climbing, and the learning ability of Aβ-overexpressing fruit flies and relieved oxidative stress. In conclusion, we proved that OST antagonizes microglial activation induced by either LPS or Aβ and that NRF2 is necessary for OST's antagonism.

Nutritive Importance and Therapeutics Uses of Three Different Varieties (Murraya koenigii, Micromelum minutum, and Clausena indica) of Curry Leaves: An Updated Review

Murraya koenigii (M. koenigii), Micromelum minutum (M. minutum), and Clausena indica (C. indica) are three varieties of curry leaves in the family Rutaceae. They have been widely used in Ayurvedic medicine worldwide in the treatment and prevention of various diseases. Earlier findings provide strong evidence to support the three curry leaf species' potent pharmaceutical and biological effects, including antioxidant, antidiabetic, anti-inflammatory, and antitumor activities. Various parts of these plants, such as leaves, seeds, flowers, and fruit, contain constituents responsible for the modulation of numerous biological processes. Leading constituents of curry leaves play a crucial role in diabetic and anticancer management by regulating various molecular pathways, including Bcl-2, Bax, NF-κB, and TNFα, according to in vitro and in vivo models established. Therefore, this review summarizes the current knowledge on research achievements made in terms of phytoconstituents, their structures, biological activities, and pharmacological actions with clinical studies of curry leaves up to date. The review also emphasizes the necessity for comprehensive research studies on the pharmacological actions and the mechanisms of selected phytochemicals of M. koenigii, M. minutum, and C. indica to validate their efficacy as potent herbal remedies for many ailments.

Antifungal Activity and Action Mechanism Study of Coumarins from Cnidium monnieri Fruit and Structurally Related Compounds

The increasing resistance of plant diseases caused by phytopathogenic fungi highlights the need for highly effective and environmentally benign agents. The antifungal activities of Cnidium monnieri fruit extracts and five isolated compounds as well as structurally related coumarins against five plant pathogenic fungi were evaluated. The acetone extract, which contained the highest amount of five coumarins, showed strongest antifungal activity. Among the coumarin compounds, we found that 4-methoxycoumarin exhibited stronger and broader antifungal activity against five phytopathogenic fungi, and was more potent than osthol. Especially, it could significantly inhibit the growth of Rhizoctonia solani mycelium with an EC₅₀ value of 21 μg mL^-1 . Further studies showed that 4-methoxycoumarin affected the structure and function of peroxisomes, inhibited the β-oxidation of fatty acids, decreased the production of ATP and acetyl coenzyme A, and then accumulated ROS by damaging MMP and the mitochondrial function to cause the cell death of R. solani mycelia. 4-Methoxycoumarin presented antifungal efficacy in a concentration- dependent manner in vivo and could be used to prevent the potato black scurf. This study laid the foundation for the future development of 4-methoxycournamin as an alternative and friendly biofungicide.

The Protective Effect of Natural Compounds on Doxorubicin-Induced Cardiotoxicity via Nicotinamide Adenine Dinucleotide Phosphate Oxidase Inhibition

OBJECTIVES

Doxorubicin (DOX) is widely prescribed for the treatment of several human cancers. Unfortunately, cumulative doses of DOX are the main cause of myocardial dysfunction. Although preclinical and pharmaceutical studies were performed to investigate the potential of natural compounds in minimizing DOX toxicity, a comprehensive review of them is not available. This review can help the researchers for an effective search strategy.

KEY FINDINGS

Oxidative stress and p53 play an important role in DOX-associated cardiotoxicity. DOX activates nicotinamide adenine dinucleotide phosphate NADPH oxidase (NOX) in the heart, resulting in excessive reactive oxygen species that can induce cardiomyocyte apoptosis through phosphorylation of p53, DNA damage and/or mitogen-activated protein kinases-mediated cardiomyocyte apoptosis. Although a few chemical drugs with high efficacy are administered along with DOX to prevent or more likely to reduce cardiovascular toxicity, their use is often limited by additional side effects. Recently, attention has been drawn to natural compounds that prevent DOX cardiotoxicity. This review focuses on some of the natural bioactive compounds with potential therapeutic efficacy against DOX-induced cardiotoxicity (DIC).

SUMMARY

Some natural compounds, especially flavonols, flavonoids and proanthocyanidins, have the most protective effects against DIC by forming stable radicals and preventing the assembly of the NOX subunits.

Ligands and Signaling of Mas-Related G Protein-Coupled Receptor-X2 in Mast Cell Activation

Mas-related G protein-coupled receptor-X2 (MRGPRX2) is known as a novel receptor to activate mast cells (MCs). MRGPRX2 plays a dual role in promoting MC-dependent host defense and immunomodulation and contributing to the pathogenesis of pseudo-allergic drug reactions, pain, itching, and inflammatory diseases. In this article, we discuss the possible signaling pathways of MCs activation mediated by MRGPRX2 and summarize and classify agonists and inhibitors of MRGPRX2 in MCs activation. MRGPRX2 is a low-affinity and low-selectivity receptor, which allows it to interact with a diverse group of ligands. Diverse MRGPRX2 ligands utilize conserved residues in its transmembrane (TM) domains and carboxyl-terminus Ser/Thr residues to undergo ligand binding and G protein coupling. The coupling likely initiates phosphorylation cascades, induces Ca²⁺ mobilization, and causes degranulation and generation of cytokines and chemokines via MAPK and NF-κB pathways, resulting in MCs activation. Agonists of MRGPRX2 on MCs are divided into peptides (including antimicrobial peptides, neuropeptides, MC degranulating peptides, peptide hormones) and nonpeptides (including FDA-approved drugs). Inhibitors of MRGPRX2 include non-selective GPCR inhibitors, herbal extracts, small-molecule MRGPRX2 antagonists, and DNA aptamer drugs. Screening and classifying MRGPRX2 ligands and summarizing their signaling pathways would improve our understanding of MRGPRX2-mediated physiological and pathological effects on MCs.

Osthole Attenuates Macrophage Activation in Experimental Asthma by Inhibitingthe NF-ĸB/MIF Signaling Pathway

Inhibition of activated macrophages is an alternative therapeutic strategy for asthma. We investigated whether a coumarin compound, osthole, isolated from Cnidium monnieri (L.) Cuss, alleviated macrophage activation in vivo and in vitro. Osthole could reduce expression of a marker of activated macrophages, cluster of differentiation (CD)206, in an ovalbumin-challenge model of asthma in mice. Osthole could also inhibit infiltration of inflammatory cells, collagen deposition and production of proinflammatory cytokines [interleukin (IL)-1β, tumor necrosis factor-ɑ, macrophage migration inhibitory factor (MIF)] in asthmatic mice. In vitro, expression of phosphorylated-IĸBɑ, MIF and M2 cytokines (Ym-1, Fizz-1, arginase-1) in IL-4-induced macrophages decreased upon exposure to the NF-ĸB inhibitor MG-132. In our short hairpin (sh)RNA-MIF-knockdown model, reduced expression of M2 cytokines was detected in the IL-4 + shRNA-MIF group. Osthole could attenuate the proliferation and migration of an IL-4-induced rat alveolar macrophages line (NR8383). Osthole could reduce IL-4-induced translocation of nuclear factor-kappa B (NF-ĸB) in NR8383 cells. Collectively, our results suggest that osthole ameliorates macrophage activation in asthma by suppressing the NF-ĸB/MIF signaling pathway, and might be a potential agent for treating asthma.

The fluorescence of a mercury probe based on osthol

The ability of osthol (OST) to recognize mercury ions in aqueous solution was studied using fluorescence, UV–vis spectrophotometry, mass spectrometry, and ¹H NMR spectroscopy, and the recognition mechanism is discussed. The results showed that OST and Hg²⁺ can form a complex with a stoichiometric ratio of 1:1. The binding constant was 1.552 × 10⁵ L∙mol⁻¹, having a highly efficient and specific selectivity for Hg²⁺. The fluorescence intensity of OST showed a good linear correlation with the Hg²⁺ concentration (6.0 × 10⁻⁵ to 24.0 × 10⁻⁵ mol∙L⁻¹, R² = 0.9954), and the detection limit of the probe was 5.04 × 10⁻⁸ mol∙L⁻¹, which can be used for the determination of Hg²⁺ traces.

Osthole, a Natural Plant Derivative Inhibits MRGPRX2 Induced Mast Cell Responses

Mast cells are tissue-resident innate immune cells known for their prominent role in mediating allergic reactions. MAS-related G-protein coupled receptor-X2 (MRGPRX2) is a promiscuous G-protein coupled receptor (GPCR) expressed on mast cells that is activated by several ligands that share cationic and amphipathic properties. Interestingly, MRGPRX2 ligands include certain FDA-approved drugs, antimicrobial peptides, and neuropeptides. Consequently, this receptor has been implicated in causing mast cell-dependent pseudo-allergic reactions to these drugs and chronic inflammation associated with asthma, urticaria and rosacea in humans. In the current study we examined the role of osthole, a natural plant coumarin, in regulating mast cell responses when activated by the MRGPRX2 ligands, including compound 48/80, the neuropeptide substance P, and the cathelicidin LL-37. We demonstrate that osthole attenuates both the early (Ca2+ mobilization and degranulation) and delayed events (chemokine/cytokine production) of mast cell activation via MRGPRX2 in vitro. Osthole also inhibits MrgprB2- (mouse ortholog of human MRGPRX2) dependent inflammation in in vivo mouse models of pseudo-allergy. Molecular docking analysis suggests that osthole does not compete with the MRGPRX2 ligands for interaction with the receptor, but rather regulates MRGPRX2 activation via allosteric modifications. Furthermore, flow cytometry and confocal microscopy experiments reveal that osthole reduces both surface and intracellular expression levels of MRGPRX2 in mast cells. Collectively, our data demonstrate that osthole inhibits MRGPRX2/MrgprB2-induced mast cell responses and provides a rationale for the use of this natural compound as a safer alternative treatment for pseudo-allergic reactions in humans.

Osthole inhibited the activity of CYP2C9 in human liver microsomes and influenced indomethacin pharmacokinetics in rats

Osthol, a pharmacologically active ingredient in various traditional Chinese medicines, is predominantly metabolized by CYP2C9. It may be co-administered with other drugs which are metabolized by CYP2C9 in clinical medicine. However, CYP2C9*1/*2/*3 genotype on the pharmacokinetics of osthole and its metabolic diversity between rat and human are unclear.In this study, we investigated the effects of osthole on enzyme activity of CYP2C11/CYP2C9 in rat liver microsomes (RLMs) and human liver microsomes (HLMs), to distinguish metabolic manner of osthole in different species. Interestingly, we found that osthole inhibits the activity of CYP2C11 in a non-competitive manner in RLMs, while inhibits CYP2C9 activity in a competitive manner in pooled HLMs. Then, the effects of CYP2C9*1/*2/*3 allele on the pharmacokinetics of osthole were identified. In human CYP2C9 isoform, the Ki value of 21.93 μM (CYP2C9*1), 18.10 μM (CYP2C9*2), 13.12 μM (CYP2C9*3) indicate that there are individual differences in the inhibition of osthole on CYP2C9 activity.We investigated how the indomethacin pharmacokinetics was affected by osthole in SD rat. To estimate the area under the curve (AUC), maximum plasma concentration (C_max) and apparent clearance (CL/F), indomethacin (10 mg/kg) was given orally combined with osthole (20 mg/kg) in adult SD rat. We found the value of PK on indomethacin, such as the AUC_0-∞, was from 176.40 ± 17.29 to 173.74 ± 27.69 μg/ml h^-1, C_max from 9.02 ± 1.24 to 9.89 ± 0.82 μg/ml and CL/F from 0.11 ± 0.01 to 0.12 ± 0.04 mg/kg/h which were unsignificantly changed compared with the control groups. However, the T_max was prolonged from 2.00 ± 0.00 h to 7.33 ± 1.15 h, and T_1/2 increased from 8.38 ± 2.30 h to 11.37 ± 2.11 h. These results indicate that osthole could potentially affect the metabolism of indomethacin in vivo.

Natural Chalcones in Chinese Materia Medica: Licorice

Licorice is an important Chinese materia medica frequently used in clinical practice, which contains more than 20 triterpenoids and 300 flavonoids. Chalcone, one of the major classes of flavonoid, has a variety of biological activities and is widely distributed in nature. To date, about 42 chalcones have been isolated and identified from licorice. These chalcones play a pivotal role when licorice exerts its pharmacological effects. According to the research reports, these compounds have a wide range of biological activities, containing anticancer, anti-inflammatory, antimicrobial, antioxidative, antiviral, antidiabetic, antidepressive, hepatoprotective activities, and so on. This review aims to summarize structures and biological activities of chalcones from licorice. We hope that this work can provide a theoretical basis for the further studies of chalcones from licorice.

Osthole relieves diabetics cardiac autonomic neuropathy associated with P2X3 receptor in ratstellate ganglia

Diabetic cardiac autonomic neuropathy (DCAN) is a serious complication of diabetes mellitus, which often leads to cardiac dysfunction and even threatens patients' life. Osthole, a natural coumarin derivative, has anti-inflammatory, anti-oxidant and antihypertensive effects. The P2X3 receptor is related to DCAN. The objective of this study will investigate whether osthole relieves DCAN associated with the P2X3 receptor in the stellate ganglia of diabetic rats. A type 2 diabetes mellitus rat model was induced by a combination of diet and streptozotocin. Our results showed that osthole improved the abnormal changes of blood pressure, heart rate, and heart rate variability in diabetic rats and significantly reduced the up-regulated expression levels of the P2X3 receptor, tumor necrosis factor-α and interleukin-1β in stellate ganglia of diabetic rats. Meanwhile, osthole significantly decreased the elevated serum adrenaline concentration and phosphorylation level of extracellular regulated protein kinase 1/2. In addition, the molecular docking result indicated that osthole was a perfect fit for interacting with the P2X3 receptor. Overall, osthole alleviates the sympathetic relative excitation via inhibiting the expression of P2X3 receptors in the stellate ganglia, to achieve a balance between sympathetic and parasympathetic nerves, relieves the DCAN.

Separation and Enrichment of Three Coumarins from Angelicae Pubescentis Radix by Macroporous Resin with Preparative HPLC and Evaluation of Their Anti-Inflammatory Activity

In order to enrich and separate three coumarins (columbianetin acetate, osthole and columbianadin) from Angelicae Pubescentis Radix (APR), an efficient method was established by combining macroporous resins (MARs) with preparative high-performance liquid chromatography (PHPLC). Five different macroporous resins (D101, AB-8, DA-201, HP-20 and GDX-201) were used to assess the adsorption and desorption characteristics of three coumarins. The result demonstrated that HP-20 resin possessed the best adsorption and desorption capacities for these three coumarins. Moreover, the adsorption dynamics profiles of three coumarins were well fitted to the pseudo second order equation (R² > 0.99) for the HP-20 resin. The adsorption process was described by the three isotherms models including Langmuir (R² > 0.98, 0.046 ≤ R_L ≤ 0.103), Freundlich (R² > 0.99, 0.2748 ≤ 1/n ≤ 0.3103) and Dubinin Radushkevich (R² > 0.97). The contents of columbianetin acetate, osthole and columbianadin in the product were increased 10.69-fold, 19.98-fold and 19.68-fold after enrichment, respectively. Three coumarins were further purified by PHPLC and the purities of them reached above 98%. Additionally, the anti-inflammatory effects of these three coumarins were assessed by Lipopolysaccharide (LPS)-induced RAW 264.7 cells. It was found that the production of NO and MCP-1 was obviously inhibited by three coumarins. Columbianetin acetate, osthole and columbianadin could be used as potentially natural anti-inflammatory ingredients in pharmaceutical products. It was concluded that the new method combining MARs with PHPLC was efficient and economical for enlarging scale separation and enrichment of columbianetin acetate, osthole and columbianadin with anti-inflammatory effect from the APR extract.

5'-hydroxy Auraptene stimulates osteoblast differentiation of bone marrow-derived mesenchymal stem cells via a BMP-dependent mechanism

Background

Identifying bone anabolic agents is a superior strategy for the treatment of osteoporosis. Naturally, derived coumarin derivatives have shown osteoanabolic effect in vitro and in vivo. In this study, we investigated the effect of 5′-Hydroxy Auraptene (5′-HA), a coumarin derivative that newly isolated from Lotus lalambensis Schweinf on the differentiation of the mouse bone marrow-derived mesenchymal (skeletal) stem cells (mBMSCs) into osteoblast and adipocyte.

Methods

The effect of 5′-HA on mBMSCs cell proliferation and osteoblast differentiation was assessed by measuring cell viability, quantitative alkaline phosphatase (ALP) activity assay, Alizarin red staining for matrix mineralization and osteogenic gene array expression. Adipogenesis was measured by Oil Red O staining and quantitative real time PCR (qPCR) analysis of adipogenic markers. Regulation of BMPs signaling pathways by 5′-HA was measured by Western blot analysis and qPCR.

Results

5′-HA showed to stimulate the differentiation of mBMSCs into osteogenic cell lineage in a dose-dependent manner, without affecting their differentiation into adipocytic cell lineage. Treatment of mBMSCs with 5′-HA showed to promote significantly the BMP2-induced osteogenesis in mBMSCs via activating Smad1/5/8 phosphorylation and increasing Smad4 expression. Blocking of BMP signaling using BMPR1 selective inhibitor LDN-193189 significantly inhibited the stimulatory effect of 5′-HA on osteogenesis.

Conclusions

Our data identified 5′-HA, as a novel coumarin derivative that function to stimulate the differentiation of mBMSCs into osteoblasts in BMP-signaling dependent mechanism.

Electronic supplementary material

The online version of this article (10.1186/s12929-019-0544-7) contains supplementary material, which is available to authorized users.

Volatile Secondary Metabolites with Potent Antidiabetic Activity from the Roots of Prangos pabularia Lindl.—Computational and Experimental Investigations

(1) Background: Almost 500 million people worldwide are suffering from diabetes. Since ancient times, humans have used medicinal plants for the treatment of diabetes. Medicinal plants continue to serve as natural sources for the discovery of antidiabetic compounds. Prangos pabularia Lindl. is a widely distributed herb with large reserves in Tajikistan. Its roots and fruits have been used in Tajik traditional medicine. To our best knowledge, there are no previously published reports concerning the antidiabetic activity and the chemical composition of the essential oil obtained from roots of P. pabularia. (2) Methods: The volatile secondary metabolites were obtained by hydrodistillation from the underground parts of P. pabularia growing wild in Tajikistan and were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Protein tyrosine phosphatase 1B (PTP-1B) inhibition assay and molecular docking analysis were carried out to evaluate the potential antidiabetic activity of the P. pabularia essential oil. (3) Results: The main constituents of the volatile oil of P. pabularia were 5-pentylcyclohexa-1,3-diene (44.6%), menthone (12.6%), 1-tridecyne (10.9%), and osthole (6.0%). PTP-1B inhibition assay of the essential oil and osthole resulted in significant inhibitory activity with an IC50 value of 0.06 ± 0.01 and 0.93 ± 0.1 μg/mL. Molecular docking analysis suggests volatile compounds such as osthole inhibit PTP-1B, and the results are also in agreement with experimental investigations. (4) Conclusions: Volatile secondary metabolites and the pure isolated compound (osthole) from the roots of P. pabularia exhibited potent antidiabetic activity, twenty-five and nearly two times more than the positive control (3-(3,5-dibromo-4-hydroxybenzoyl)-2-ethylbenzofuran-6-sulfonic acid-(4-(thiazol-2-ylsulfamyl)-phenyl)-amide)) with an IC50 value of 1.46 ± 0.4 μg/mL, respectively.

One-Pot Synthesis of Novel Dibenzoxanthenes, Diarylbutanes, and Calix[4]resorcinarenes via Consecutive Pyrrolidine Ring-Closure/Ring-Opening Reactions

Herein, we report the approach to the otherwise hardly accessible dibenzoxanthenes, diarylbutanes, and calix[4]resorcinarenes possessing urea moieties based on the reaction of N-(4,4-diethoxybutyl)ureas with electron-rich aromatics in strongly acidic media. Unlike the previously developed methods, the proposed approach benefits from one-pot procedure and allows to obtain the target compounds with much higher yields.

Effect of osthole on advanced glycation end products-induced renal tubular hypertrophy and role of klotho in its mechanism of action

BACKGROUND

Osthole has been widely reported to have pharmacological activities such as anti-cancer, anti-inflammation and anti-hyperlipidemic effects. Klotho was identified as an anti-senescence protein in a variety of tissues. Loss of klotho has been associated with chronic kidney disease. However, potential roles and molecular events for osthole and klotho in diabetic nephropathy remain unclear.

PURPOSE

In the current study, we undertook to study the effect of osthole on klotho expression in advanced glycation end products (AGE)-cultured human renal proximal tubular cells, and to investigate the molecular mechanisms of osthole and exogenous klotho against AGE-induced renal tubular hypertrophy.

METHODS

Cell viability was elucidated by MTT assay. Protein expression was measured by Western blotting. mRNA level was analyzed by real-time PCR. Cellular hypertrophy growth was evaluated by hypertrophy index. Relative cell size was detected by flow cytometry.

RESULTS

We found that raising the ambient AGE concentration causes a dose-dependent decrease in klotho synthesis. Osthole significantly increased AGE-inhibited klotho mRNA and protein expression. Osthole and exogenous klotho treatments significantly attenuated AGE-induced Janus kinase 2 (JAK2)-signal transducers and activators of transcription 1 (STAT1) and STAT3 activation. Moreover, protein levels of suppressor of cytokine signaling 1 (SOCS1) and SOCS3 were augmented by osthole and exogenous klotho. The abilities of osthole and exogenous klotho to reverse AGE-induced cellular hypertrophy were verified by the observation that osthole and exogenous klotho inhibited p21^Waf1/Cip1/collagen IV/RAGE expression, total protein content, and cell size.

CONCLUSION

Consequently, we found that osthole attenuated AGE-induced renal tubular hypertrophy via induction of klotho expression and suppression of the JAK2-STAT1/STAT3 signaling. These results also showed that klotho might be used as a unique molecular target for the treatment of diabetic nephropathy.

Osthole inhibits triple negative breast cancer cells by suppressing STAT3

BACKGROUND

Triple-negative breast cancer (TNBC) is an aggressive subgroup of human breast cancer. Patients with TNBC have poor clinical outcome as they are non-responsive to current targeted therapies. There is an urgent need to identify new therapeutic targets and develop more effective treatment options for TNBC patients. Osthole, a natural product from C. monnieri, has been shown to inhibit certain cancer cells. However, the mechanisms of action as well as its effect on TNBC cells are not currently known.

METHODS

We investigated the effect of osthole in cultured TNBC cells as well as in a xenograft model of TNBC growth. We also used a high-throughput proteomics platform to identify the direct binding protein of osthole.

RESULTS

We found that osthole inhibited the growth of a panel of TNBC cells and induced apoptosis in both cultured cells and TNBC xenografts. We used a high-throughput proteomics platform and identified signal transducer and activator of transcription 3 (STAT3) as a potential binding protein of osthole. We further show that osthole suppressed STAT3 in TNBC cells to inhibit growth and induce apoptosis. Overexpressing STAT3 in TNBC reduced the effectiveness of osthole treatment.

CONCLUSIONS

These results provide support for osthole as a potential new therapeutic agent for the management of TNBC. Moreover, our results indicate that STAT3 may be targeted for the development of novel anti-TNBC drugs.

Application of Metabolomics in the Study of Natural Products

LC-MS-based metabolomics could have a major impact in the study of natural products, especially in its metabolism, toxicity and activity. This review highlights recent applications of metabolomics approach in the study of metabolites and toxicity of natural products, and the understanding of their effects on various diseases. Metabolomics has been employed to study the in vitro and in vivo metabolism of natural compounds, such as osthole, dehydrodiisoeugenol, and myrislignan. The pharmacological effects of natural compounds and extracts were determined using metabolomics technology combined with diseases models in animal, including osthole and nutmeg extracts. It has been demonstrated that metabolomics is a powerful technology for the investigation of xenobiotics-induced toxicity. The metabolism of triptolide and its hepatotoxicity were discussed. LC-MS-based metabolomics has a great potential in the druggability of natural products. The application of metabolomics should be broadened in the field of natural products in the future.

Metabolic map of osthole and its effect on lipids

1. Osthole, a coumarin compound from plants, is a promising agent for the treatment of metabolic diseases, including hyperglycemia, fatty liver, and cancers. Studies indicate that the peroxisome proliferator-activated receptors (PPAR) α and γ are involved in the pharmacological effects of osthole. The in vitro and in vivo metabolism of osthole and its biological activity are not completely understood. 2. In this study, ultra-performance chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOFMS)-based metabolomics was used to determine the metabolic pathway of osthole and its influence on the levels of endogenous metabolites. Forty-one osthole metabolites, including 23 novel metabolites, were identified and structurally elucidated from its metabolism in vitro and in vivo. Recombinant cytochrome P450s (CYPs) screening showed that CYP3A4 and CYP3A5 were the primary enzymes contributing to osthole metabolism. 3. More importantly, osthole was able to decrease the levels of lysophosphatidylethanolamine (LPE) and lysophosphatidylcholine (LPC) in the plasma, which explains in part its modulatory effects on metabolic diseases. 4. This study gives the insights about the metabolic pathways of osthole in vivo, including hydroxylation, glucuronidation, and sulfation. Furthermore, the levels of the lipids regulated by osthole indicated its potential effects on adipogenesis. These data contribute to the understanding of the disposition and pharmacological activity of osthole in vivo.

Simultaneous determination of columbianetin-β-d-glucopyranoside and columbianetin in a biological sample by high-performance liquid chromatography with fluorescence detection and identification of other columbianetin-β-d-glucopyranoside metabolites by ultra high-performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry

Columbianetin-β-d-glucopyranoside (CBG) and its metabolite columbianetin (CBN) are the bioactive constituents of Angelicae pubescentis radix (APR). They exhibit the anti-platelet aggregation, anti-inflammatory and analgesic properties. The absorption, distribution, metabolism and excretion (ADME) of CBG has not been reported to date. Both high-performance liquid chromatography with fluorescence detection and ultra high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry methods were developed and validated for the study of ADME of CBG. It was found that CBG could be catabolized into its active metabolite CBN in vivo. The absolute bioavailability of columbianetin-β-d-glucopyranoside was 5.63 ± 4.42%. The other co-existing constituents from the APR ethanol extract could enhance the absorption of CBG. CBG and CBN were rapidly and broadly distributed in the stomach, ovary, kidney, liver, spleen, lung, muscles, heart and brain. Higher levels of accumulation of CBG and CBN were detected in the ovary and kidney tissues. Eight metabolites of CBG were tentatively identified in blood, urine, bile and faeces of rats after oral administration of pure CBG. It was also found that CBG and CBN were mainly excreted through the faecal route. It can be concluded that the validated methods were successfully applied for absorption, distribution, metabolism and excretion study of CBG.

Protective effects of Ficus carica leaves on glucose and lipids levels, carbohydrate metabolism enzymes and β-cells in type 2 diabetic rats

CONTEXT

The decoctions of Ficus carica Linn. (Moraceae) leaves are used in the folklore treatment of diabetes.

OBJECTIVE

To evaluate the effect of F. carica on glucose and lipids levels, carbohydrate metabolism enzymes and β-cells protective effects in type 2 diabetes.

MATERIAL AND METHODS

Diabetes was induced in 15 days high-fat diet (HFD)-fed Wistar rats by intraperitoneal injection of streptozotocin (STZ) (40 mg/kg). The ethyl acetate extract (250 and 500 mg/kg) of F. carica leaves was administered for 28 days. Oral glucose tolerance (OGTT) and intraperitoneal insulin tolerance tests (ITT) were evaluated on 15th and 25th days, respectively.

RESULTS

The ethyl acetate extract (250 and 500 mg/kg) of n F. carica leaves showed significant effect (p < 0.005) in the levels of blood glucose, total cholesterol (TC), triglycerides (TG), body weight and hepatic glycogen. In OGTT, F. carica (250 and 500 mg/kg) significantly (p < 0.005) detained the increase in blood glucose levels at 60 and 120 min and in ITT, F. carica enhanced the glucose utilization significantly (p < 0.005) over 30 and 60 min compared to diabetic control. Further, the altered activities of key carbohydrate metabolizing enzymes such as glucose-6-phosphatase, fructose-1,6-bisphosphatase and hexokinase in the liver tissue of diabetic rats were significantly (p < 0.005) reverted to near normal levels upon treatment with F. carica. Immumohistochemical studies of islets substantiated the cytoprotective effect on pancreatic β-cells.

DISCUSSION AND CONCLUSIONS

F. carica leaves exerted significant effect on carbohydrate metabolism enzymes with promising hypoglycemic and hypolipidemic activities in type 2 diabetic rats.

Cnidimonins A-C, Three Types of Hybrid Dimer from Cnidium monnieri: Structural Elucidation and Semisynthesis

Three pairs of racemic dimers, (±)-cnidimonins A-C (1-3), were isolated from the fruits of Cnidium monnieri. They represent novel hybrid-dimerization patterns of coumarin skeleton with structurally diverse units (flavonol, benzofuran, and chromone) via an unprecedented terminal chiral carbon of prenyl. The absolute configurations of the enantiomers were determined by electronic circular dichroism (ECD). To investigate their bioactivities in depth, (±)-cnidimonins A-C (1-3) were synthesized. The racemic mixture (±)-1 exhibited stronger antiviral activity against HSV-1 (IC₅₀: 1.23 μM) than its corresponding optically pure enantiomers.

Coumarins as potential antidiabetic agents

OBJECTIVES

Even with great advances in modern medicine and therapeutic agent development, the search for effective antidiabetic drugs remains challenging. Coumarins are secondary metabolites found widely in nature plants and used mainly in anticoagulation and antithrombotic therapy. Over the past two decades, however, there has been an increasing body of literatures related to the effects of coumarins and their derivatives on diabetes and its complications. This review aimed to focus on research findings concerning the effects of coumarins against diabetes and its complications using in-vitro and in-vivo animal models, and also to discuss cellular and molecular mechanisms underlying these effects.

KEY FINDINGS

The search for new coumarins against diabetes and it complications, either isolated from traditional medicine or chemically synthesized, has been constantly expanding. The cellular and molecular mechanisms involved include protecting pancreatic beta cells from damage, improving abnormal insulin signalling, reducing oxidative stress/inflammation, activating AMP-activated protein kinase (AMPK), inhibiting α-glucosidases and ameliorating diabetic complications.

CONCLUSIONS

The effects and mechanisms of coumarins and their derivatives upon diabetes and its complications are discussed in current review. Further investigations remain to be carried out to develop a promising antidiabetic agent based on coumarin cores.

The potential of natural products for targeting PPARα

Peroxisome proliferator activated receptors (PPARs) α, -γ and -β/δ are ligand-activated transcription factors and members of the superfamily of nuclear hormone receptor. These receptors play key roles in maintaining glucose and lipid homeostasis by modulating gene expression. PPARs constitute a recognized druggable target and indeed several classes of drugs used in the treatment of metabolic disease symptoms, such as dyslipidemia (fibrates, e.g. fenofibrate and gemfibrozil) and diabetes (thiazolidinediones, e.g. rosiglitazone and pioglitazone) are ligands for the various PPAR isoforms. More precisely, antidiabetic thiazolidinediones act on PPARγ, while PPARα is the main molecular target of antidyslipidemic fibrates. Over the past few years, our understanding of the mechanism underlying the PPAR modulation of gene expression has greatly increased. This review presents a survey on terrestrial and marine natural products modulating the PPARα system with the objective of highlighting how the incredible chemodiversity of natural products can provide innovative leads for this "hot" target.

Osthole inhibits bone metastasis of breast cancer

Bone is one of the most common sites for breast cancer metastasis, which greatly contributes to patient morbidity and mortality. Osthole, a major extract from Cnidium monnieri (L.), exhibits many biological and pharmacological activities, however, its potential as a therapeutic agent in the treatment of breast cancer bone metastases remain poorly understood. In this study, we set out to investigate whether osthole could inhibit breast cancer metastasis to bone in mice and clarified the potential mechanism of this inhibition. In the murine model of breast cancer osseous metastasis, mice that received osthole developed significantly less bone metastases and displayed decreased tumor burden when compared with mice in the control group. Osthole inhibited breast cancer cell growth, migration, and invasion, and induced apoptosis of breast cancer cells. Additionally, it also regulated OPG/RANKL signals in the interactions between bone cells (osteoblasts and osteoclasts) and cancer cells. Besides, it also inhibited TGF-β/Smads signaling in breast cancer metastasis to bone in MDA-231BO cells. The results of this study suggest that osthole has real potential as a therapeutic candidate in the treatment of breast cancer patients with bone metastases.

Anti-asthmatic activity of osthole in an ovalbumin-induced asthma murine model

Osthole, an active coumarin extracted from the dried fruits of Cnidium monnieri (L.) Cusson, is known to possess a variety of pharmacological activities. In the present study, we investigated and illuminated the mechanisms underlying the protective effects of osthole in an experimental model of allergic asthma. Our results show that osthole treatment significantly reduced the OVA-induced increase in serum IgE and inflammatory cytokines (IL-4, IL-5, IL-13) in bronchoalveolar lavage fluid (BALF), and decreased the recruitment of inflammatory cells in BALF and the lung. It also effectively attenuated goblet cell hyperplasia and mucus overproduction in lung tissue. In addition, western blot analysis demonstrated that osthole blocked NF-κB activation, which may be associated with a reduction in inflammatory cytokine production. These data suggest that osthole attenuated OVA-induced allergic asthma inflammation by inhibiting NF-κB activation. The present study identified the molecular mechanisms of action of osthole, which support the potential pharmaceutical application of osthole treatment for asthma and other airway inflammation disorders.

Microwave-assisted synthesis and antifungal activity of novel fused Osthole derivatives

Based on the microwave-assisted synthetic protocol developed in our previous work, we have synthesized a series of novel furo[3,2-c]coumarins as fused Osthole derivatives, via the reaction of 4-hydroxycoumarins and β-ketoesters catalyzed by DMAP. All the target compounds were evaluated in vitro for their antifungal activity against six phytopathogenic fungi, some compounds exhibited potential activity in the primary assays. Especially compounds 6c, 7b, 8b and 8c (shown in Fig. 1) were the most active ones, EC₅₀ values of these four compounds against Colletotrichum capsica, Botrytis cinerea and Rhizoctonia solani were further investigated. 6c was identified as the most promising candidate with the EC₅₀ value at 0.110 μM against Botrytis cinerea and 0.040 μM against Colletotrichum capsica, respectively, representing better antifungal activity than that of the commonly used fungicide Azoxystrobin.

Anti-Leishmania Activity of Osthole

BACKGROUND

Treatment of cutaneous leishmaniasis (CL) is occasionally highly resistant to pentavalent antimonials, the gold standard in pharmacotherapy of CL. Since there is no effective vaccine, the discovery of natural antileishmanial products as complementary therapeutic agents could be used to improve the current regimens.

OBJECTIVE

In this study in vitro and in vivo antileishmanial activities of osthole, a natural coumarin known to possess antibacterial and parasiticidal activities are evaluated.

MATERIALS AND METHODS

Leishmania major infected J774.A1 macrophages were treated with increasing concentrations of osthole. CL lesions of BALB/c mice were treated topically with 0.2% osthole.

RESULTS

Osthole exhibited dose-dependent leishmanicidal activity against intracellular amastigotes with IC50 value of 14.95 μg/ml. Treatment of CL lesions in BALB/c mice with osthole significantly declined lesion progression compared to untreated mice (P < 0.05), however did not result in recovery.

CONCLUSION

Osthole demonstrated remarkable leishmanicidal activity in vitro. Higher concentrations of osthole may demonstrate the therapeutic property in vivo.

SUMMARY

In vitro and in vivo antileishmanial activities of osthole, a pernylated coumarin extracted from Prangos asperula Boiss., are studied against Leishmania major.

Coumarin heterocyclic derivatives: chemical synthesis and biological activity

This review highlights the broad range of science that has arisen from the synthesis of coumarin-linked and fused heterocycle derivatives. Specific topics include their synthesis and biological activity.

Osthole improves glucose and lipid metabolism via modulation of PPARα/γ-mediated target gene expression in liver, adipose tissue, and skeletal muscle in fatty liver rats

CONTEXT

Osthole may be a dual agonist of peroxisome proliferator-activated receptors (PPAR) α/γ and ameliorate the insulin resistance (IR), but its mechanisms are not yet understood completely.

OBJECTIVE

We investigated the effects of osthole on PPARα/γ-mediated target genes involved in glucose and lipid metabolism in liver, adipose tissue, and skeletal muscle in fatty liver and IR rats.

MATERIALS AND METHODS

The rat model was established by orally feeding high-fat and high-sucrose emulsion for 9 weeks. The experimental rats were treated with osthole 5-10 mg/kg by gavage after feeding the emulsion for 6 weeks, and were sacrificed 4 weeks after administration.

RESULTS

After treatment with osthole 5-10 mg/kg for 4 weeks, the lipid levels in serum and liver were decreased by 37.9-67.2% and 31.4-38.5% for triglyceride, 33.1-47.5% and 28.5-31.2% for free fatty acid, respectively, the fasting blood glucose, fasting serum insulin, and homeostasis model assessment of IR were also decreased by 17.2-22.7%, 25.9-26.7%, and 37.5-42.8%, respectively. Osthole treatment might simultaneously decrease the sterol regulatory element binding protein-1c, diacylglycerol acyltransferase, and fatty acid synthase mRNA expressions in liver and adipose tissue, and increase the carnitine palmitoyltransferase-1A mRNA expression in liver and glucose transporter-4 mRNA expression in skeletal muscle, especially in the osthole 10 mg/kg group (p < 0.01).

DISCUSSION AND CONCLUSION

Osthole can improve glucose and lipid metabolism in fatty liver and IR rats, and its mechanisms may be associated with synergic modulation of PPARα/γ-mediated target genes involved in glucose and lipid metabolism in liver, adipose tissue, and skeletal muscle.

Cnidium monnieri: A Review of Traditional Uses, Phytochemical and Ethnopharmacological Properties

Cnidium monnieri (L.) Cuss., an annual plant of the Umbelliferae species is one of the most widely used traditional herbal medicines and its fruits have been used to treat a variety of diseases in China, Vietnam, and Japan. The aim of this review is to provide an up-to-date and comprehensive analysis of the botany, traditional uses, phytochemistry, pharmacology, toxicity and contraindication of Cnidium monnieri (L.) Cuss. and to provide future directions of research on this plant. To date, 350 compounds have been isolated and identified from Cnidium monnieri (L.) Cuss., including the main active constituent, coumarins. In vitro and in vivo studies suggest that osthole and other coumarin compounds possess wide range of pharmacological properties for the treatment of female genitals, male impotence, frigidity, skin-related diseases, and exhibit strong antipruritic, anti-allergic, antidermatophytic, antibacterial, antifungal, anti-osteoporotic effects. Although coumarins have been identified as the main active constituents responsible for the observed pharmacological effects, the molecular mechanisms of their actions are still unknown. Therefore, further studies are still required to reveal the structure-activity relationship of these active constituents. In addition, toxicological and clinical studies are also required to provide further data for pharmaceutical use.

Osthole: A Review on Its Bioactivities, Pharmacological Properties, and Potential as Alternative Medicine

This paper reviews the latest understanding of biological and pharmacological properties of osthole (7-methoxy-8-(3-methyl-2-butenyl)-2H-1-benzopyran-2-one), a natural product found in several medicinal plants such as Cnidium monnieri and Angelica pubescens. In vitro and in vivo experimental results have revealed that osthole demonstrates multiple pharmacological actions including neuroprotective, osteogenic, immunomodulatory, anticancer, hepatoprotective, cardiovascular protective, and antimicrobial activities. In addition, pharmacokinetic studies showed osthole uptake and utilization are fast and efficient in body. Moreover, the mechanisms of multiple pharmacological activities of osthole are very likely related to the modulatory effect on cyclic adenosine monophosphate (cAMP) and cyclic adenosine monophosphate (cGMP) level, though some mechanisms remain unclear. This review aims to summarize the pharmacological properties of osthole and give an overview of the underlying mechanisms, which showcase its potential as a multitarget alternative medicine.

Umbelliferone Improves an Impaired Glucose and Lipid Metabolism in High-Fat Diet/Streptozotocin-Induced Type 2 Diabetic Rats

Umbelliferone (UMB) is a natural product that has several pharmacological effects including antihyperglycemic activity in diabetic rats. Thus, the objective of this study was to investigate the effect of UMB on insulin resistance and on the regulation of glucose and lipid metabolism in type 2 diabetic rats. Type 2 diabetes was induced in rats by feeding a high-fat diet (45 kcal% fat) and a single dose of streptozotocin injection. After 8 weeks of treatment, UMB significantly reduced the elevated blood glucose levels and insulin resistance and increased the liver glycogen and serum adiponectin. Moreover, the serum lipid and the storages of triglyceride and non-esterified fatty acid in liver tissue were reduced. From histological examination, the lipid droplets in liver tissue were clearly decreased, and the fat cell size in the fat tissue was smaller in diabetic rats treated with UMB. Interestingly, UMB increased fat cell adiponectin, plasma membrane glucose transporter 4 (GLUT4) and peroxisome proliferator-activated receptor gamma (PPARγ), and liver PPARα protein expressions. Our findings demonstrate that UMB improves glucose and lipid metabolism in type 2 diabetes by stimulating the insulin secretion and the related mechanisms via stimulating expression of adiponectin, GLUT4, PPARγ, and PPARα-protein expressions. Copyright © 2015 John Wiley & Sons, Ltd.