Coumarins from the root of Angelica gigas Nakai

Angelica gigas: Signature Compounds, In Vivo Anticancer, Analgesic, Neuroprotective and Other Activities, and the Clinical Translation Challenges

Angelica gigas Nakai (AGN) root is a medicinal herbal widely used in traditional medicine in Korea. AGN root ethanolic extract dietary supplements are marketed in the United States for memory health and pain management. We comprehensively reviewed the anticancer, analgesic, pro-memory and other bio-activities of AGN extract and its signature phytochemicals decursin, decursinol angelate, and decursinol a decade ago in 2012 and updated their anticancer activities in 2015. In the last decade, significant progress has been made for understanding the pharmacokinetics (PK) and metabolism of these compounds in animal models and single dose human PK studies have been published by us and others. In addition to increased knowledge of the known bioactivities, new bioactivities with potential novel health benefits have been reported in animal models of cerebral ischemia/stroke, anxiety, sleep disorder, epilepsy, inflammatory bowel disease, sepsis, metabolic disorders, osteoporosis, osteoarthritis, and even male infertility. Herein, we will update PK and metabolism of pyranocoumarins, review in vivo bioactivities from animal models and human studies, and critically appraise the relevant active compounds, the cellular and molecular pharmacodynamic targets, and pertinent mechanisms of action. Knowledge gaps include whether human pyranocoumarin PK metrics are AGN dose dependent and subjected to metabolic ceiling, or metabolic adaptation after repeated use. Critical clinical translation challenges include sourcing of AGN extracts, product consistency and quality control, and AGN dose optimization for different health conditions and disease indications. Future research directions are articulated to fill knowledge gaps and address these challenges.

Cytotoxic Activity, Cell Cycle Inhibition, and Apoptosis-Inducing Potential of Athyrium hohenackerianum (Lady Fern) with Its Phytochemical Profiling

In the present study, we investigated the cytotoxic effects of Athyrium hohenackerianum ethanolic extract (AHEE) on the proliferation of breast, lung, and colon cancer cells. The AHEE was tested for its effect on the progression of the cell cycle, followed by induction of apoptosis determination by flow cytometry. Real-time qRT-PCR was also utilized to observe the initiation of apoptosis. In addition, GC-MS was performed in order to identify the active phytochemicals present in the AHEE. A cytotoxic activity with an IC₅₀ value of 123.90 μg/mL against HCT-116 colon cancer cells was exhibited by AHEE. Following propidium iodide staining, annexin-V/PI, and clonogenic assays, AHEE treatment results in cell arrest in the S phase, causing an increase in the early and late phases of apoptosis and displaying antiproliferative potential, respectively. The morphological alterations were further monitored using acridine orange/ethidium bromide (AO/EB) staining. When compared with the control cells, features of apoptotic cell death, including nuclear fragmentation, in the AHEE-treated cells were noticed. The apoptosis was also confirmed by detecting the increased expression of p53 and caspase-3 along with the downregulation of Bcl-2. GC-MS analysis revealed that trans-linalool oxide, loliolide, phytol, 4,8,12,16-tetramethylheptadecan-4-olide, and gamma-sitosterol were the major phytochemical constituents. Based on these findings, it can be suggested that AHEE causes cellular death via apoptosis, which should be further explored for the identification of active compounds responsible for these observed effects. Therefore, AHEE can be used in the pharmaceutical development of anticancer agents for cancer therapeutics.

Potentiation of decursinol angelate on pentobarbital-induced sleeping behaviors via the activation of GABAA-ergic systems in rodents

Angelicae Gigantis Radix (AGR, Angelica gigas) has been used for a long time as a traditional folk medicine in Korea and oriental countries. Decursinol angelate (DCA) is structurally isomeric decursin, one of the major components of AGR. This study was performed to confirm whether DCA augments pentobarbital-induced sleeping behaviors via the activation of GABA_A-ergic systems in animals. Oral administration of DCA (10, 25 and 50 mg/kg) markedly suppressed spontaneous locomotor activity. DCA also prolonged sleeping time, and decreased the sleep latency by pentobarbital (42 mg/kg), in a dose-dependent manner, similar to muscimol, both at the hypnotic (42 mg/kg) and sub-hypnotic (28 mg/kg) dosages. Especially, DCA increased the number of sleeping animals in the sub-hypnotic dosage. DCA (50 mg/kg, p.o.) itself modulated sleep architectures; DCA reduced the counts of sleep/wake cycles. At the same time, DCA increased total sleep time, but not non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. In the molecular experiments. DCA (0.001, 0.01 and 0.1 µg/ml) increased intracellular Cl- influx level in hypothalamic primary cultured neuronal cells of rats. In addition, DCA increased the protein expression of glutamic acid decarboxylase (GAD_65/67) and GABA_A receptors subtypes. Taken together, these results suggest that DCA potentiates pentobarbital-induced sleeping behaviors through the activation of GABA_A-ergic systems, and can be useful in the treatment of insomnia.

Decursin inhibits osteoclastogenesis by downregulating NFATc1 and blocking fusion of pre-osteoclasts

Bone sustains its structure through dynamic interaction between osteoblastic cells and osteoclastic cells. But imbalance may lead to osteoporosis caused by overactivated osteoclast cells that have bone-resorbing function. Recently, herbs have been researched as major sources of medicines in many countries. In vitro and in vivo anti-osteoclastogenic activity of Angelica gigas NAKAI have been reported, but the biological activity of decursin, its major component in osteoclast differentiation is still unknown. Therefore, in this study, we explored whether decursin could affect RANKL-mediated osteoclastogenesis. The results showed that decursin efficiently inhibited RANKL-activated osteoclast differentiation by inhibiting transcriptional and translational expression of NFATc1, a major factor in RANKL-mediated osteoclastogenesis. Furthermore, decursin decreased fusion and migration of pre-osteoclasts by downregulating mRNA expression levels of DC-STAMP and β3 integrin, respectively. In addition, decursin prevents lipopolysaccharide (LPS)-induced bone erosion in vivo. In summary, decursin could prevent osteoclastogenesis and inflammatory bone loss via blockage of NFATc1 activity and fusion and migration of pre-osteoclasts, and it could be developed as a potent phytochemical candidate for treating pathologies of bone diseases.

Natural product inhibitors of ocular angiogenesis

Natural products are characterized by high chemical diversity and biochemical specificity; therefore, they are appealing as lead compounds for drug discovery. Given the importance of angiogenesis to many pathologies, numerous natural products have been explored as potential anti-angiogenic drugs. Ocular angiogenesis underlies blinding eye diseases such as retinopathy of prematurity (ROP) in children, proliferative diabetic retinopathy (DR) in adults of working age, and age-related macular degeneration (AMD) in the elderly. Despite the presence of effective therapy in many cases, these diseases are still a significant health burden. Anti-VEGF biologics are the standard of care, but may cause ocular or systemic side effects after intraocular administration and patients may be refractory. Many anti-angiogenic compounds inhibit tumor growth and metastasis alone or in combination therapy, but a more select subset of them has been tested in the context of ocular neovascular diseases. Here, we review the promise of natural products as anti-angiogenic agents, with a specific focus on retinal and choroidal neovascularization. The multifunctional curcumin and the chalcone isoliquiritigenin have demonstrated promising anti-angiogenic effects in mouse models of DR and choroidal neovascularization (CNV) respectively. The homoisoflavanone cremastranone and the flavonoid deguelin have been shown to inhibit ocular neovascularization in more than one disease model. The isoflavone genistein and the flavone apigenin on the other hand are showing potential in the prevention of retinal and choroidal angiogenesis with long-term administration. Many other products with anti-angiogenic potential in vitro such as the lactone withaferin A, the flavonol quercetin, and the stilbenoid combretastatin A4 are awaiting investigation in different ocular disease-relevant animal models. These natural products may serve as lead compounds for the design of more specific, efficacious, and affordable drugs with minimal side effects.

Ultrafine Angelica gigas powder normalizes ovarian hormone levels and has antiosteoporosis properties in ovariectomized rats: particle size effect

The root of Angelica gigas (Korean angelica) is traditionally used to treat women's ailments that are caused by an impairment of menstrual blood flow and cycle irregularities. This study evaluated the effect particle size of Korean angelica powder on its efficacy for treating estrogen-related symptoms of menopause. Initially, Korean angelica roots were pulverized into ultrafine powder, and orally administered to the rats at a concentration of 500 mg/kg body weight for 8 weeks. The effects of Korean angelica powder particle size on extraction yield, contents of bioactive compounds (decursin and decursinol angelate), levels of serum ovarian hormones (estradiol and progesterone), reproductive hormones (luteinizing hormone and follicle-stimulating hormone), and experimental osteoporosis parameters (mineral density, strength, and histological features) were determined. A significant increase (fivefold) in the contents of decursin and decursinol angelate in the extract of the ultrafine Korean angelica powder was observed compared to coarse Korean angelica powder. Rats were divided into sham-operated or ovariectomized (OVX) groups that were fed coarse (CRS) or ultrafine (UF) ground Korean angelica root. The serum levels of estradiol in the OVX_UF group were 19.2% and 54.1% higher than that of OVX_CRS group. Serum bone-alkaline phosphatase/total-alkaline phosphatase index in the OVX_UF group was half that of the OVX_CRS group. In addition, less trabecular bone loss and thick cortical areas were observed in rats administered ultrafine powder. Therefore, ultrafine grinding may enhance the bioactivity of herbal medicines and be especially useful when their extracted forms lose bioactivity during processing, storage, and oral intake.

Chemical and biological assessment of angelica roots from different cultivated regions in a chinese herbal decoction danggui buxue tang

Roots of Angelica sinensis (Danggui) have been used in promoting blood circulation as herbal medicine for over 2000 years in China. Another species of Angelica roots called A. gigas is being used in Korea. To reveal the efficiency of different Angelica roots, the chemical and biological properties of Angelica roots from different cultivated regions were compared. Roots of A. sinensis contained higher levels of ferulic acid, Z-ligustilide, and senkyunolide A, while high amounts of butylphthalide and Z-butylenephthalide were found in A. gigas roots. The extracts deriving from A. gigas roots showed better effects in osteogenic and estrogenic properties than that of A. sinensis from China. However, this difference was markedly reduced when the Angelica roots were being prepared in a Chinese herbal decoction together with Astragali Radix as Danggui Buxue Tang. In contrast, the herbal decoction prepared from A. sinensis roots showed better responses in cell cultures. In addition, the extracts of A. gigas roots showed strong cell toxicity both as single herb and as Danggui Buxue Tang. This result revealed the distinct properties of Angelica roots from China and Korea suggesting the specific usage of herb in preparing a unique herbal decoction.

Effect of decursin on the pharmacokinetics of theophylline and its metabolites in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Decursin is used as a traditional Asian medicine to treat various women's diseases.

AIM OF THE STUDY

Herb-drug interaction has become a serious problem since herbal medicine is extensively used in the modern world. This study investigates effects of decursin, on the pharmacokinetics of theophylline, a typical substrate of cytochrome P450 1A2 enzyme, in rats.

MATERIALS AND METHODS

After decursin pretreatment for 3 days, on the fourth day rats were administered decursin and theophylline concomitantly. The blood theophylline and its major metabolites (1-methylxanthine (1-MX), 3-methylxanthine (3-MX), 1-methyluric acid (1-MU), and 1,3-dimethyluric acid (1,3-DMU)) levels were monitored with LC-MS/MS.

RESULTS

The results indicated that the clearance, elimination rate constant (K(el)) of theophylline was significantly decreased and area under concentration-time curve (AUC), C(max), half-life was increased in decursin (25mg/kg) pretreatment when theophylline (10mg/kg) was given. In the presence of decursin, the pharmacokinetic parameters of three metabolites (1-MX, 1,3-DMU, and 1-MU) were affected and the differences were statistically significant about AUC(24)(h) parameter.

CONCLUSION

Our results suggest that patients who want to use CYP1A2-metabolized drugs such as caffeine and theophylline should be advised of the potential herb-drug interaction, to reduce therapeutic failure or increased toxicity of conventional drug therapy.

Metabolite profiling of Angelica gigas from different geographical origins using 1H NMR and UPLC-MS analyses

Angelica gigas obtained from different geographical regions was characterized using (1)H nuclear magnetic resonance (NMR) spectroscopy and ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) followed by multivariate data analyses. Principal component analysis (PCA) and orthogonal partial least-squares-discriminant analysis (OPLS-DA) score plots from (1)H NMR and UPLC-MS data sets showed a clear distinction among A. gigas from three different regions in Korea. The major metabolites that contributed to the discrimination factor were primary metabolites including acetate, choline, citrate, 1,3-dimethylurate, fumarate, glucose, histamine, lactose, malate, N-acetylglutamate, succinate, and valine and secondary metabolites including decursin, decursinol, nodakenin, marmesin, 7-hydroxy-6-(2R-hydroxy-3-methylbut-3-ethyl)coumarin in A. gigas roots. The results demonstrate that (1)H NMR and UPLC-MS-based metabolic profiling coupled with chemometric analysis can be used to discriminate the geographical origins of various herbal medicines and to identify primary and secondary metabolites responsible for discrimination.

Inhibition of cyclooxygenase-2-dependent survivin mediates decursin-induced apoptosis in human KBM-5 myeloid leukemia cells

We demonstrate that decursin induces apoptosis via regulation of cyclooxygenase-2 (COX-2) and survivin in leukemic KBM-5 cells. By activating an apoptotic machinery, decursin is cytotoxic to KBM-5 cells. In this apoptotic process, decursin can activate caspase family members and triggers PARP cleavage. At the same time, the expression of COX-2 and survivin in the cells is downregulated. Furthermore, decursin is in synergy with COX-2 inhibitor, celecoxib or NS398 for the induction of apoptosis. Overall, these results suggest that decursin, via inhibiting COX-2 and survivin, sensitizes human leukemia cells to apoptosis and is a potential chemotherapeutic agent to treat this disease.

The Cytotoxic Properties of Natural Coumarins Isolated from Roots of Ferulago campestris (Apiaceae) and of Synthetic Ester Derivatives of Aegelinol

Grandivittin (1), agasyllin (2), aegelinol benzoate (3) and felamidin (20), four natural coumarins isolated from Ferulago campestris, and several synthetic ester derivatives of aegelinol (4) were tested against four tumor cell lines. Some of them were shown to be marginally cytotoxic against the A549 lung cancer cell line.

Decursin inhibits VEGF-mediated inner blood-retinal barrier breakdown by suppression of VEGFR-2 activation

The blood-retinal barrier (BRB) is essential for the normal structural and functional integrity of the retina, whose breakdown could cause the serious vision loss. Vascular endothelial growth factor (VEGF), as a permeable factor, induces alteration of tight junction proteins to result in BRB breakdown. Herein, we demonstrated that decursin inhibits VEGF-mediated inner BRB breakdown through suppression of VEGFR-2 signaling pathway. In retinal endothelial cells, decursin inhibited VEGF-mediated hyperpermeability. Decursin prevented VEGF-mediated loss of tight junction proteins including zonula occludens-1 (ZO-1), ZO-2, and occludin in retinal endothelial cells, which was also supported by restoration of tight junction proteins in intercellular junction. In addition, decursin significantly inhibited VEGF-mediated vascular leakage from retinal vessels, which was accompanied by prevention of loss of tight junction proteins in retinal vessels. Decursin significantly suppressed VEGF-induced VEGFR-2 phosphrylation that consequently led to inhibition of extracellular signal-regulated kinase (ERK) 1/2 activation. Moreover, decursin induced no cytotoxicity to retinal endothelial cells and no retinal toxicity under therapeutic concentrations. Therefore, our results suggest that decursin prevents VEGF-mediated BRB breakdown through blocking of loss of tight junction proteins, which might be regulated by suppression of VEGFR-2 activation. As a novel inhibitor to BRB breakdown, decursin could be applied to variable retinopathies with BRB breakdown.

Decursin and decursinol inhibit VEGF-induced angiogenesis by blocking the activation of extracellular signal-regulated kinase and c-Jun N-terminal kinase

The root of Angelica gigas Nakai contains two major coumarins, which have been previously identified as decursin and decursinol. Decursin has been demonstrated to exhibit potent anti-cancer activity both in vitro and in vivo. In this study, we found that decursin and decursinol at non-cytotoxic doses inhibited the VEGF-induced proliferation, migration, and capillary-tube formation of HUVECs. Moreover, decursin and decursinol suppressed microvessel formation on chorioallantoic membranes in fertilized eggs and into mouse Matrigel plugs. The oral administration of decursin and decursinol also reduced VEGF-induced angiogenesis in Matrigel. Furthermore, decursin and decursinol reduced the phosphorylation of ERK and JNK, but not p38 MAPK, in VEGF-stimulated HUVECs. Taken together, our results reveal that decursin and decursinol inhibit VEGF-induced angiogenesis by reducing the activation of ERK and JNK in HUVECs, and possess potent in vivo anti-angiogenic activity, coupled with the advantage of oral dosing. Thus, these compounds may have the potential for the treatment of cancers dependent on VEGF-induced vascularization.

Decursin and decursinol angelate inhibit VEGF-induced angiogenesis via suppression of the VEGFR-2-signaling pathway

Inhibition of angiogenesis is an attractive approach for the treatment of angiogenic diseases, such as cancer. Vascular endothelial growth factor (VEGF) is one of the most important activators of angiogenesis and interacts with the high-affinity tyrosine kinase receptors, VEGFR-1 and VEGFR-2. The pyranocoumarin compounds decursin and decursinol angelate isolated from the herb, Angelica gigas, are known to possess potent anti-inflammatory activities. However, little is known about their antiangiogenic activity or their underlying mechanisms. Here, we show the antiangiogenic effects of decursin and decursinol angelate using in vitro assays and in vivo animal experiments. Decursin and decursinol angelate inhibited VEGF-induced angiogenic processes in vitro, including proliferation, migration and tube formation of human umbilical vein endothelial cells. Decursin and decursinol angelate significantly suppressed neovessel formation in chick chorioallantoic membrane and tumor growth in a mouse model. The microvessel density in tumors treated with decursin for 14 days was significantly decreased compared with a vehicle control group. Decursin and decursinol angelate inhibited VEGF-induced phosphorylation of VEGFR-2, extracellular signal-regulated kinases and c-Jun N-terminal kinase mitogen-activated protein kinases. Taken together, these results demonstrate that decursin and decursinol angelate are novel candidates for inhibition of VEGF-induced angiogenesis.

Decursin and decursinol angelate inhibit estrogen-stimulated and estrogen-independent growth and survival of breast cancer cells

Introduction

Estrogen and estrogen receptor (ER)-mediated signaling are crucial for the etiology and progression of human breast cancer. Attenuating ER activities by natural products is a promising strategy to decrease breast cancer risk. We recently discovered that the pyranocoumarin compound decursin and its isomer decursinol angelate (DA) have potent novel antiandrogen receptor signaling activities. Because the ER and the androgen receptor belong to the steroid receptor superfamily, we examined whether these compounds affected ER expression and signaling in breast cancer cells.

Methods

We treated estrogen-dependent MCF-7 and estrogen-independent MDA MB-231 human breast cancer cells with decursin and DA, and examined cell growth, apoptosis, and ERα and ERβ expression in both cell lines – and, in particular, estrogen-stimulated signaling in the MCF-7 cells. We compared these compounds with decursinol to determine their structure-activity relationship.

Results

Decursin and DA exerted growth inhibitory effects on MCF-7 cells through G₁ arrest and caspase-mediated apoptosis. These compounds decreased ERα in MCF-7 cells at both mRNA and protein levels, and suppressed estrogen-stimulated genes. Decursin and the pure antiestrogen Faslodex™ exerted an additive growth inhibitory effect on MCF-7 cells. In MDA MB-231 cells, these compounds induced cell-cycle arrests in the G₁ and G₂ phases as well as inducing apoptosis, accompanied by an increased expression of ERβ. In contrast, decursinol, which lacks the side chain of decursin and DA, did not have these cellular and molecular activities at comparable concentrations.

Conclusion

The side chain of decursin and DA is crucial for their anti-ER signaling and breast cancer growth inhibitory activities. These data provide mechanistic rationales for validating the chemopreventive and therapeutic efficacy of decursin and its derivatives in preclinical animal models of breast cancer.

Irritant and cytotoxic coumarins from Angelica glauca Edgew roots

Irritant and cytotoxic potentiality of six coumarins, isolated for the first time from the roots of Angelica glauca identified as 5,6,7-trimethoxycoumarin, 6-methoxy-7,8-methylenedioxycoumarin, bergapten, decursinol angelate, decursin, and nodakenetin, were investigated. The irritant potential was explored by open mouse ear assay, evaluating their ID(50) after acute and by IU (Irritant units) after chronic effects, while the cytotoxic capability was explored by their LC(50), using brine shrimp (Artemia salina) larvae (nauplii). All the coumarins exhibited well-defined irritancy on mouse's ears, compared with the positive controlled euphorbium reaction and cytotoxic response against brine shrimp larvae, compared with the positive control colchicine. Decursinol angelate and decursin were the most potent and persistent irritant compounds with least ID(50), whose reactions lasted for 48 h. 6-Methoxy-7,8-methylenedioxycoumarin and bergaten revealed an intermediate irritant reactions, while 5,6,7-trimethoxycoumarin and nodakenetin displayed the least irritant and least persistent reactions on mouse ears. Both decursin and decursinol angelate also appeared to be the stronger cytotoxic agents than other coumarins. 5,6,7-trimethoxycoumarin displayed an intermediate cytotoxic behaviour, while other three coumarins, i.e., 6-methoxy-7,8-methylenedioxycoumarin, bergapten, and nodakenetin, exhibited the least cytotoxic capacity against brine shrimp larvae.

The simultaneous determination of coumarins in Angelica gigas root by high performance liquid chromatography-diode array detector coupled with electrospray ionization/mass spectrometry

An high performance liquid chromatography-diode array detector coupled with electrospray ionization/mass spectrometry (HPLC-DAD/MS) based method has been developed for the simultaneous determination of nine coumarin compounds, nodakenin (1), peucedanone (2), marmesin (3), decursinol (4), 7-hydroxy-6-(2R-hydroxy-3-methylbut-3-enyl)coumarin (5), demethylsuberosin (6), decursin (7), decursinol angelate (8) and isoimperatorin (9) in the Korean medicinal herb, Cham-Dang-Gui, the dried root of Angelica gigas (Umbelliferae). The methanol extracts were analyzed by HPLC using a reversed-phase C18 column (5 microm, 4.5 mm x 250 mm) using a gradient acetonitrile-water solvent system at a flow rate of 1.0 ml/min. The analysis of six coumarins (1, 3, 4 and 6-8) with DAD was done at 330 nm and showed excellent linearity (r(2)=0.998-0.999) in a range of 0.2-250 microg/ml for all the compounds. The average recoveries (n=3) were between 96.5% and 110.8%. Identification of each peak was also discussed with the electrospray ionization multi-stage tandem mass spectroscopy (ESI-MS(n)). The amount of these coumarin compounds was evaluated in A. gigas samples. Meanwhile, three coumarins (2, 5 and 9) could not been quantified by DAD because these peaks were overlapped with others. Determination of these compounds could be successfully accomplished with the HPLC-ESI/MS in selected ion monitoring/selected reaction monitoring mode.

Oriental herbs as a source of novel anti-androgen and prostate cancer chemopreventive agents

Androgen and androgen receptor (AR) signaling are crucial for the genesis of prostate cancer (PCa), which can often develop into androgen-ligand-independent diseases that are lethal to the patients. Recent studies show that even these hormone-refractory PCa require ligand-independent AR signaling for survival. As current chemotherapy is largely ineffective for PCa and has serious toxic sideeffects, we have initiated a collaborative effort to identify and develop novel, safe and naturally occurring agents that target AR signaling from Oriental medicinal herbs for the chemoprevention and treatment of PCa. We highlight our discovery of decursin from an Oriental formula containing Korean Angelica gigas Nakai (Dang Gui) root as a novel anti-androgen/AR agent. We have identified the following mechanisms to account for the specific anti-AR actions: rapid block of AR nuclear translocation, inhibition of binding of 5alpha-dihydrotestesterone to AR and increased proteasomal degradation of AR protein. Furthermore, decursin lacks the agonist activity of the "pure" anti-androgen bicalutamide and is more potent than bicalutamide in inducing PCa apoptosis. Structure-activity analyses reveal a critical requirement of the side-chain on decursin or its structural isomer decursinol angelate for anti-AR, cell cycle arrest and proapoptotic activities. This work demonstrates the feasibility of using activity-guided fractionation in cell culture assays combined with mechanistic studies to identify novel anti-androgen/ AR agents from complex herbal mixtures.

Mechanism-Based Inactivation of Cytochrome P450 2A6 by Decursinol Angelate Isolated fromAngelica Gigas

The inhibition of CYP2A6 by decursinol angelate, a pyranocoumarin isolated from Angelica gigas roots, was examined in human liver microsomes and recombinant CYP2A6. Decursinol angelate moderately inhibited coumarin 7-hydroxylation, but a 20-min preincubation with microsomes and NADPH significantly increased its inhibitory effect (IC(50); >20 versus 4.4 microM). A similar inhibition pattern was observed in nicotine C oxidation, which is also one of the prototype reactions of CYP2A6. Inactivation by decursinol angelate was selective for CYP2A6 and characterized by K(I) values of 0.99 and 2.42 microM and the k(inact) values of 0.136 and 0.053 min(-1) in microsomes and recombinant CYP2A6, respectively. This inactivation was not protected or restored by nucleophiles, reactive oxygen scavengers, or extensive dialysis but was inhibited by the addition of a competitive CYP2A6 inhibitor, pilocarpine. Furthermore, incubation of CYP2A6 with decursinol angelate in the presence of NADPH resulted in a loss of the spectral CYP2A6 content. An in vitro metabolism study revealed that CYP2A6 oxidized decursinol angelate to the dihydrodiol metabolite, presumably via an epoxide intermediate that might be responsible for the inactivation of CYP2A6. These results collectively demonstrated that decursinol angelate inactivated CYP2A6 in a mechanism-based mode.

Anti-tumor activities of decursinol angelate and decursin from Angelica gigas

The in vivo anti-tumor activities of decursinol angelate (1) and decursin (2) isolated from the roots of Angelica gigas were investigated. These two compounds, when administered consecutively for 9 days at 50 and 100 mg/kg i.p. in mice, caused a significant increase in the life span and a significant decrease in the tumor weight and volume of mice inoculated with Sarcoma-180 tumor cells. These results suggest that decursinol angelate (1) and decursin (2) from A. gigas have anti-tumor activities.

Antinociceptive profiles of crude extract from roots of Angelica gigas NAKAI in various pain models

To characterize the antinociceptive profiles of Angelica gigas NAKAI (ANG; Korean angelica), methanol extract from the dried roots of ANG was made and mice were administered orally at the various doses (from 0.25 to 3 g/kg). ANG produced the increased latencies of the tail-flick and hot-plate paw-licking responses in a dose-dependent manner. In acetic acid-induced writhing test, ANG dose-dependently decreased writhing numbers. Moreover, the cumulative response time of nociceptive behaviors induced by intraplantar formalin injection was reduced during both the 1st and the 2nd phases in a dose-dependent manner in ANG-treated mice. Furthermore, oral administration of ANG did not cause licking, scratching and biting responses induced by TNF-alpha (100 pg), IFN-gamma (100 pg) or IL-1beta (100 pg) injected intrathecally (i.t.), especially at higher dose (3 g/kg). Additionally, in ANG treated mice, the cumulative nociceptive response time for i.t. administration of substance P or capsaicin was dose-dependently diminished. Finally, nociceptive responses elicited by i.t. injection of glutamate (20 microg), N-methyl-D-aspartic acid (60 ng), alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (13 ng) or kainic acid (12 ng) were decreased by oral administration of ANG. Our results suggest that ANG produces antinociception via acting on the central nervous system and shows antinociceptive profiles in various pain models, especially inflammatory pain.

Antibacterial coumarins from Angelica gigas roots

Systematic fractionation of Angelica gigas roots led to the isolation of linear furano(pyrano)coumarins such as bergapten (1), decursinol angelate (2), decursin (3), nodakenetin (4) and nodakenin (5). The antibacterial activities of those compounds against pathogenic bacteria were investigated. Among the compounds tested, decursinol angelate (2) and decursin (3) exhibited significant antibacterial activity against Bacillus subtilis with the minimum inhibitory concentrations (MICs) of 50 and 12.5 microg/mL, respectively.

Coumarins isolated from Angelica gigas inhibit acetylcholinesterase: structure-activity relationships

Acetylcholinesterase (AChE) inhibitory activity-guided fractionation of Angelica gigas led to isolation and identification of a new coumarin, peucedanone (12), and isolation of 11 known coumarins. Among them, decursinol (1) represented the highest inhibitory activity toward AChE in vitro. The correlation of the inhibitory activities of the coumarins toward AChE with their chemical structures was studied.