Immunomodulatory effect of arctigenin, a lignan compound, on tumour necrosis factor-alpha and nitric oxide production, and lymphocyte proliferation

An integrated network pharmacology and molecular docking approach to reveal the role of Arctigenin against Cutibacterium acnes-induced skin inflammation by targeting the CYP19A1

Acne caused by inflammation of hair follicles and sebaceous glands is a common chronic skin disease. Arctigenin (ATG) is an extract of Arctium lappa L., which has significant anti-inflammatory effects. However, the effect and mechanism of ATG in cutaneous inflammation mediated by Cutibacterium acnes (C. acnes) has not been fully evaluated. The purpose of this study was to explore the effect and potential mechanism of ATG in the treatment of acne through network pharmacology and experimental confirmation. An acne model was established by injected live C. acnes into living mice and treated with ATG. Our data showed that ATG effectively improved acne induced by live C. acnes, which was confirmed by determining ear swelling rate, estradiol concentration and hematoxylin and eosin (H&E) staining. In addition, ATG inhibited the NLRP3 inflammasome signaling pathway in mice ear tissues and reduced the secretion of pro-inflammatory cytokines IL-1β to relieve inflammation. The results of network pharmacology and molecular docking confirmed that ATG can regulate 17β-Estradiol (E2) levels through targeted to CYP19A1, and finally inhibited skin inflammation. Taken together, our results confirmed that ATG regulated E2 secretion by targeting CYP19A1, thereby inhibiting the NLRP3 inflammasome signaling pathway and improving inflammation levels in acne mice. This study provides a basis for the feasibility of ATG in treating acne in clinical practice.

Metabolomic Profiles and Biopharmaceutical Properties of Petrosimonia brachiata and P. nigdeensis from Turkey

Halophytic plants possess a huge range of active constituents and medicinal benefits. In this study, extracts (water, ethanol, ethyl acetate, dichloromethane, and n-hexane) of two halophytes of the genus Petrosimonia (P. brachiata and P. nigdeensis) were investigated for their phytochemical profiles and pharmacological properties. The phytochemical profiles of both species were investigated using an untargeted metabolomics approach based on high-resolution mass spectrometry. The two species show different polyphenolic profiles and these are influenced by the different extraction solvents used. The same extracts were used for different bioactivity assays. The results show that all extracts yielded total flavonoid and phenolic contents of 11.14-24.22 mg GAE/g and 3.15-22.03 mg RE/g, respectively. While extracts of both species demonstrated a radical scavenging ability in the ABTS assay (16.12-98.02 mg TE/g), only the polar and moderately polar extracts (water, ethanol, and ethyl acetate) showed scavenging potential in the DPPH assay (4.74-16.55 mg TE/g). A reducing potential was also displayed by all extracts in the CUPRAC and FRAP assays (26.02-80.35 mg TE/g and 31.70-67.69 mg TE/g, respectively). The total antioxidant capacity of the extracts ranged from 0.24 to 2.17 mmol TE/g, and the metal chelating activity ranged from 14.74 to 33.80 mg EDTAE/g. The water extracts possessed a higher metal chelating power than the other extracts. All extracts acted as inhibitors of acetylcholinesterase (0.16-3.85 mg GALAE/g) and amylase (0.11-1.28 mmol ACAE/g). Moreover, apart from the water extracts, the other extracts also showed anti-butyrylcholinesterase activity (0.73-2.86 mg GALAE/g), as well as anti-tyrosinase (36.74-61.40 mg KAE/g) and anti-glucosidase (2.37-2.73 mmol ACAE/g) potential. In general, the water extracts were found to be weak inhibitors of the tested enzymes, while the ethanol extracts mostly showed an inhibitory effect. The obtained findings revealed the antioxidant and enzyme inhibitory properties of these two species and demonstrated that the solvent type used affected the pharmacological properties of the extracts and hence, can be useful to further investigate the active constituents yielded in the extracts and understand the mechanisms involved.

Anthriscus sylvestris-Noxious Weed or Sustainable Source of Bioactive Lignans?

Anthriscus sylvestris (L.) Hoffm. (Apiaceae), commonly known as wild chervil, has gained scientific interest owing to its diverse phytochemical profile and potential therapeutic applications. The plant, despite being categorized as a noxious weed, is traditionally used in treating various conditions like headaches, dressing wounds, and as a tonic, antitussive, antipyretic, analgesic, and diuretic. Its pharmacological importance stems from containing diverse bioactive lignans, especially aryltetralins and dibenzylbutyrolactones. One of the main compounds of A. sylvestris, deoxypodophyllotoxin, among its wide-ranging effects, including antitumor, antiproliferative, antiplatelet aggregation, antiviral, anti-inflammatory, and insecticidal properties, serves as a pivotal precursor to epipodophyllotoxin, crucial in the semisynthesis of cytostatic agents like etoposide and teniposide. The main starting compound for these anticancer medicines was podophyllotoxin, intensively isolated from Sinopodophyllum hexandrum, now listed as an endangered species due to overexploitation. Since new species are being investigated as potential sources, A. sylvestris emerges as a highly promising candidate owing to its abundant lignan content. This review summarizes the current knowledge on A. sylvestris, investigating its biological and morphological characteristics, and pharmacological properties. Emphasizing the biological activities and structure-activity relationship, this review underscores its therapeutic potential, thus encouraging further exploration and utilization of this valuable plant resource.

Anti-Gene IGF-I Vaccines in Cancer Gene Therapy: A Review of a Case of Glioblastoma

OBJECTIVE

Vaccines for the deadliest brain tumor - glioblastoma (GBM) - are generally based on targeting growth factors or their receptors, often using antibodies. The vaccines described in the review were prepared to suppress the principal cancer growth factor - IGF-I, using anti-gene approaches either of antisense (AS) or of triple helix (TH) type. Our objective was to increase the median survival of patients treated with AS and TH cell vaccines.

METHODOLOGY

The cells were transfected in vitro by both constructed IGF-I AS and IGF-I TH expression episomal vectors; part of these cells was co-cultured with plant phytochemicals, modulating IGF-I expression. Both AS and TH approaches completely suppressed IGF-I expression and induced MHC-1 / B7 immunogenicity related to the IGF-I receptor signal.

RESULTS

This immunogenicity proved to be stronger in IGF-I TH than in IGF-I AS-prepared cell vaccines, especially in TH / phytochemical cells. The AS and TH vaccines generated an important TCD8+ and TCD8+CD11b- immune response in treated GBM patients and increased the median survival of patients up to 17-18 months, particularly using TH vaccines; in some cases, 2- and 3-year survival was reported. These clinical results were compared with those obtained in therapies targeting other growth factors.

CONCLUSION

The anti-gene IGF-I vaccines continue to be applied in current GBM personalized medicine. Technical improvements in the preparation of AS and TH vaccines to increase MHC-1 and B7 immunogenicity have, in parallel, allowed to increase in the median survival of patients.

A systematic review on botany, ethnopharmacology, quality control, phytochemistry, pharmacology and toxicity of Arctium lappa L. fruit

ETHNOPHARMACOLOGICAL RELEVANCE

Arctium lappa L., is a biennial plant that grows around the Eurasia. Many parts of Arctium lappa L. (roots, leaves and fruits, etc.) are medically used in different countries. Arctium lappa L. fruit, also called Arctii Fructus, is traditionally applied to dispel wind-heat, ventilate lung to promote eruption, remove toxicity substance and relieve sore throat.

THE AIM OF THE REVIEW

The review aims to integrate the botany, ethnopharmacology, quality control, phytochemistry, pharmacology, derivatives and toxicity information of Arctii Fructus, so as to facilitate future research and explore the potential of Arctii Fructus as an agent for treating diseases.

MATERIALS AND METHODS

Related knowledge about Arctii Fructus were acquired from Science Direct, GeenMedical, PubMed, China National Knowledge Infrastructure (CNKI), Web of Science, Pharmacopoeia of the People's Republic of China, Doctoral and Master's thesis, ancient books, etc. RESULTS: Arctii Fructus as an herb used for medicine and food was pervasively distributed and applicated around the world. It was traditionally used to treat anemopyretic cold, dyspnea and cough, sore throat, etc. To date, more than 200 compounds have been isolated and identified from Arctii Fructus. It contained lignans, phenolic acids and fatty acids, terpenoids, volatile oils and others. Lignans, especially arctigenin and arctiin, had the extensive pharmacological effects such as anti-cancer, antiviral, anti-inflammatory activities. The ester derivatives of arctigenin had the anti-cancer, anti-Alzheimer's disease and immunity enhancing effects. Although Arctii Fructus extract had no toxicity, arctigenin was toxic at a certain dose. The alleviating effects of Arctii Fructus on chronic inflammation and ageing have been demonstrated by clinical studies.

CONCLUSION

Arctii Fructus is regarded as a worthy herb with many chemical components and various pharmacological effects. Several traditional applications have been supported by modern pharmacological research. However, their action mechanisms need to be further studied. Although many chemical components were isolated from Arctii Fructus, the current research mainly focused on lignans, especially arctiin and arctigenin. Therefore, it is very important to deeply clarify the pharmacological activities and action mechanism of the compounds and make full medicinal use of the resources of Arctii Fructus.

Japanese Encephalitis Virus: An Update on the Potential Antivirals and Vaccines

Japanese encephalitis virus (JEV) is the causal agent behind Japanese encephalitis (JE), a potentially severe brain infection that spreads through mosquito bites. JE is predominant over the Asia-Pacific Region and has the potential to spread globally with a higher rate of morbidity and mortality. Efforts have been made to identify and select various target molecules essential in JEV’s progression, but until now, no licensed anti-JEV drug has been available. From a prophylactic point of view, a few licensed JE vaccines are available, but various factors, viz., the high cost and different side effects imposed by them, has narrowed their global use. With an average occurrence of >67,000 cases of JE annually, there is an urgent need to find a suitable antiviral drug to treat patients at the acute phase, as presently only supportive care is available to mitigate infection. This systematic review highlights the current status of efforts put in to develop antivirals against JE and the available vaccines, along with their effectiveness. It also summarizes epidemiology, structure, pathogenesis, and potential drug targets that can be explored to develop a new range of anti-JEV drugs to combat JEV infection globally.

Arctigenin: pharmacology, total synthesis, and progress in structure modification

Arctium lappa L. is a prevalent medicinal herb and a health supplement that is commonly used in Asia. Over the last few decades, the bioactive component arctigenin has attracted the attention of researchers because of its anti-inflammatory, antioxidant, immunomodulatory, multiple sclerosis fighting, antitumor, and anti-leukemia properties. After summarising the research and literature on arctigenin, this study outlines the current status of research on pharmacological activity, total synthesis, and structural modification of arctigenin. The purpose of this study is to assist academics in obtaining a more comprehensive understanding of the research progress on arctigenin and to provide constructive suggestions for further investigation of this useful molecule.

Protective effect and possible mechanism of arctiin on broilers challenged by Salmonella pullorum

This study was aimed to investigate the effects of dietary arctiin (ARC) supplementation (100, 200, and 400 mg/kg) on the growth performance and immune response of broilers after a Salmonella pullorum (S. pullorum) challenge, and we conducted in vitro antibacterial test to explore the bacteriostatic mechanism of ARC. The in vivo trial was randomly assigned to six groups: noninfected control (NC) group and positive control (PC) group received a basal diet; TET group, received a basal diet supplemented with 100 mg/kg chlortetracycline; ARC100, ARC200, and ARC400 groups received a basal diet containing 100, 200, and 400 mg/kg ARC, respectively. From days 14 to 16, all birds (except the NC group) were infected with 1 mL (1 × 108 CFU per mL) fresh S. pullorum culture by oral gavage per day. In vivo results showed that dietary supplementation of 200 mg/kg ARC significantly increased average daily gain (P < 0.05) and decreased feed-to-gain ratio of broilers vs. the PC group during days 15 to 28 after being challenged with S. pullorum (P < 0.05). The jejunal crypt depth (CD) was decreased by supplementing 100 or 200 mg/kg ARC in diets compared with PC birds at day 19 (P < 0.05). The jejunal villi height (VH) was increased by supplementing 100, 200, or 400 mg/kg ARC in diets compared with PC birds at day 28 (P < 0.05). Besides, dietary supplementation of 200 mg/kg ARC increased the jejunal VH to CD ratio than the PC group both at days 19 and 28 (P < 0.05). Notably, the broilers had lower serum lipopolysaccharide and diamine oxidase levels in the ARC100 and ARC200 groups at day 28 than those in the PC group (P < 0.05). Furthermore, in comparison to PC birds, the birds in ARC groups (100, 200, and 400 mg/kg) had higher serum contents of IgM and IL-10, and the birds in the ARC200 group had higher serum contents of IgA at day 19 (P < 0.05). At day 28, the birds in ARC groups (100, 200, and 400 mg/kg) had lower serum contents of IL-8, and the birds in the ARC200 group had lower serum contents of IFN-γ compared with PC birds (P < 0.05). The in vitro experiment showed that ARC significantly inhibited the biofilm formation and adhesion of S. pullorum (P < 0.05). Metabonomics analysis revealed that ARC can restrain the formation of the biofilm by affecting a variety of metabolic pathways of S. pullorum. Therefore, dietary supplementation of 200 mg/kg ARC might be a potential way to substitute antibiotics to control S. pullorum infection in broilers.

Antiviral drug research for Japanese encephalitis: an updated review

Japanese encephalitis (JE) caused by the Japanese encephalitis virus (JEV) is one of Asia's most common viral encephalitis. JEV is a flavivirus, common in rural and sub-urban regions of Asian countries. Although only 1% of JEV-infected individuals develop JE, there is a 20-30% chance of death among these individuals and possible neurological sequelae post-infection. No licensed anti-JE drugs are currently available, despite extensive efforts to develop them. Literature search was performed using databases such as PubMed Central, Google Scholar, Wiley Online Library, etc. using keywords such as Japanese encephalitis virus, antiviral drugs, antiviral drug screening, antiviral drug targets, etc. From around 230 papers/abstracts and research reviews retrieved and reviewed for this study, approximately 180 most relevant and important ones have been cited. Different approaches in drug testing and various antiviral drug targets explored so far have been thoroughly searched from the literature and compiled, besides addressing the future perspectives of the antiviral drug development strategies. Although the development of effective anti-JE drugs is an urgent issue, only supportive care is currently available. Recent advancements in understanding the biology of infection and new drug targets have been promising improvements. Despite hindrances such as the unavailability of a proper drug delivery system or a treatment regimen irrespective of the stage of infection, several promising anti-JE candidate molecules are in different phases of clinical trials. Nonetheless, efficient therapy against JEV is expected to be achieved with drug combinations and a highly targeted drug delivery system soon.

Optimisation of the Conversion and Extraction of Arctigenin From Fructus arctii Into Arctiin Using Fungi

Fructus arctii is commonly used in Chinese medicine, and arctiin and arctigenin are its main active ingredients. Arctiin has low bioavailability in the human body and needs to be converted into arctigenin by intestinal microbes before it can be absorbed into the blood. Arctigenin has antiviral, anti-inflammatory, and anti-tumour effects and its development has important value. In this study, we used external microbial fermentation with Aspergillus awamori and Trichoderma reesei to process and convert arctiin from F. arctii powder into arctigenin, hence increasing its bioavailability. We developed a fermentation process by optimising the carbon and nitrogen source/ratio, fermentation time, pH, liquid volume, inoculation volume, and substrate solid-liquid ratio. This allowed for an arctiin conversion rate of 99.84%, and the dissolution rate of the final product was 95.74%, with a loss rate as low as 4.26%. After the fermentation of F. arctii powder, the average yield of arctigenin is 19.51 mg/g. Crude fermented F. arctii extract was purified by silica gel column chromatography, and we observed an arctigenin purity of 99.33%. Our technique effectively converts arctiin and extracts arctigenin from F. arctii and provides a solid basis for further development and industrialisation.

Plant Phenolics as Pathogen-Carrier Immunogenicity Modulator Haptens

Background

Pathogens use multiple mechanisms to disrupt cell functioning in their host and allow pathogenesis. These mechanisms involve communication between the pathogen and the host cell through protein-protein interactions.

Methods

Protein-protein interactions chains referred to as signal transduction pathways are the processes by which a chemical or physical signal transmits through a cell as series of molecular events so the pathogen needs to intercept these molecular pathways at few positions to induce pathogenesis such as pathogen viability, infection or hypersensitivity.

Results

The pathogen nodes of interception are not necessarily the most immunogenic; so that novel immunogenicity-improvement strategies need to be developed thought a chemical conjugation of the pathogen-carrier nodes to develop an efficient immune response in order to block pathogenesis. On the other hand, if pathogen-carriers are immunogens; toleration ought to be induced by this conjugation avoiding hypersensitivity. Thus, this paper addresses the biological plausibility of plant-phenolics as pathogen-carrier immunogenicity modulator haptens.

Conclusion

The plant-phenolic compounds have in their structure functional groups such as hydroxyl, carbonyl, carboxyl, ester, or ether, capable of reacting with the amino or carbonyl groups of the amino acids of a pathogen-carrier to form conjugates. Besides, the varied carbon structures these phenolic compounds have; it is possible to alter the pathogen-carrier related factors that determine the immunogenicity: 1) Structural complexity, 2) Molecular size, 3) Structural heterogeneity, 4) Accessibility to antigenic determinants or epitopes, 5) Optical configuration, 6) Physical state, or 7) Molecular rigidity.

Arctigenin prevents the progression of osteoarthritis by targeting PI3K/Akt/NF-κB axis: In vitro and in vivo studies

Osteoarthritis (OA), which is principally featured by progressive joint metabolic imbalance and subsequent degeneration of articular cartilage, is a common chronic joint disease. Arctigenin (ATG), a dietary phyto-oestrogen, has been described to have potent anti-inflammatory effects. Nevertheless, its protective effects on OA have not been clearly established. The target of our following study is to evaluate the protective effects of ATG on IL-1β-induced human OA chondrocytes and mouse OA model. Our results revealed that the ATG pre-treatment effectively decreases the level of pro-inflammatory mediators, such as prostaglandin E2 (PGE2), nitrous oxide (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), IL-6 and tumour necrosis factor alpha (TNF-α) in IL-1β-induced human chondrocytes. In addition, ATG protects against the degradation of extracellular matrix (ECM) under the stimulation of IL-1β and the possible mechanism might be connected with the inactivation of phosphatidylinositol-3-kinase (PI3K)/Akt/nuclear factor-kappa B (NF-κB) axis. Furthermore, a powerful binding capacity between ATG and PI3K was also uncovered in our molecular docking research. Meanwhile, ATG may act as a protector on the mouse OA model. Collectively, all these findings suggest that ATG could be utilized as a promising therapeutic agent for the treatment of OA.

Arctium Species Secondary Metabolites Chemodiversity and Bioactivities

Arctium species are known for a variety of pharmacological effects due to their diverse volatile and non-volatile secondary metabolites. Representatives of Arctium species contain non-volatile compounds including lignans, fatty acids, acetylenic compounds, phytosterols, polysaccharides, caffeoylquinic acid derivatives, flavonoids, terpenes/terpenoids and volatile compounds such as hydrocarbons, aldehydes, methoxypyrazines, carboxylic and fatty acids, monoterpenes and sesquiterpenes. Arctium species also possess bioactive properties such as anti-cancer, anti-diabetic, anti-oxidant, hepatoprotective, gastroprotective, antibacterial, antiviral, antimicrobial, anti-allergic, and anti-inflammatory effects. This review aims to provide a complete overview of the chemistry and biological activities of the secondary metabolites found in therapeutically used Arctium species. Summary of pharmacopeias and monographs contents indicating the relevant phytochemicals and therapeutic effects are also discussed, along with possible safety considerations.

Arctigenin improves lipid metabolism by regulating AMP-activated protein kinase and downstream signaling pathways

Although it has been reported that arctigenin (ARG) can reduce the body weight and inhibit adipogenic differentiation by activating AMP-activated protein kinase (AMPK), the exact signals responsible for the ARG-mediated antiobesity mechanism through AMPK are not well understood. In this study, we investigated the potential improvement of AGR on lipid metabolism using a high-fat diet (HFD)-induced hyperlipidemia rats and 3T3-L1 mature adipocytes. The levels of AMPK and its downstream factors were examined by Western blot analysis and real-time fluorescent quantitative polymerase chain reaction. We observed that ARG lowered the HFD-induced body weight and the levels of serum lipid. Moreover, ARG clearly alleviated fat deposition in the liver and reduced epididymal fat accumulation. ARG also suppressed lipogenesis and lipolysis but promoted fatty acid β-oxidation in adipocytes. Most importantly, ARG increased the phosphorylation of AMPK and acetyl-CoA carboxylase (ACC) and upregulated the messenger RNA levels of downstream genes related to fatty acid β-oxidation, such as carnitine palmitoyltransferase 1 and acyl-CoA oxidase 1 but downregulated the expression of peroxisome proliferator-activated receptor γ (PPARγ), sterol regulatory element-binding transcription factor 1 (SREBP1c) and their targets, including lipogenesis-related genes such as CCAAT/enhancer-binding protein α, lipoprotein lipase, adipocyte protein 2, and fatty acid synthase (FAS), as well as lipolysis-related genes such as adipose triglyceride lipase and hormone-sensitive lipase. The activity of FAS was also decreased by ARG. We conclude that AMPK activation is important for the pharmacological effects of ARG. ARG may improve lipid metabolism by regulating the AMPK-ACC and AMPK-PPARγ/SREBP1c signaling pathways.

Overview of the anti-inflammatory effects, pharmacokinetic properties and clinical efficacies of arctigenin and arctiin from Arctium lappa L

Arctigenin (AR) and its glycoside, arctiin, are two major active ingredients of Arctium lappa L (A lappa), a popular medicinal herb and health supplement frequently used in Asia. In the past several decades, bioactive components from A lappa have attracted the attention of researchers due to their promising therapeutic effects. In the current article, we aimed to provide an overview of the pharmacology of AR and arctiin, focusing on their anti-inflammatory effects, pharmacokinetics properties and clinical efficacies. Compared to acrtiin, AR was reported as the most potent bioactive component of A lappa in the majority of studies. AR exhibits potent anti-inflammatory activities by inhibiting inducible nitric oxide synthase (iNOS) via modulation of several cytokines. Due to its potent anti-inflammatory effects, AR may serve as a potential therapeutic compound against both acute inflammation and various chronic diseases. However, pharmacokinetic studies demonstrated the extensive glucuronidation and hydrolysis of AR in liver, intestine and plasma, which might hinder its in vivo and clinical efficacy after oral administration. Based on the reviewed pharmacological and pharmacokinetic characteristics of AR, further pharmacokinetic and pharmacodynamic studies of AR via alternative administration routes are suggested to promote its ability to serve as a therapeutic agent as well as an ideal bioactive marker for A lappa.

Arctigenin protects against ultraviolet-A-induced damage to stemness through inhibition of the NF-κB/MAPK pathway

The stemness of stem cells is negatively affected by ultraviolet A (UVA) irradiation. This study was performed to examine the effects of arctigenin on UVA-irradiation-induced damage to the stemness of human mesenchymal stem cells (hMSCs) derived from adipose tissue. The mechanisms of action of arctigenin were also investigated. A BrdU-incorporation assay demonstrated that arctigenin attenuated the UVA-induced reduction of the cellular proliferative potential. Arctigenin also increased the UVA-induced reduction in stemness of hMSCs by upregulating stemness-related genes such as SOX2, OCT4, and NANOG. In addition, the UVA-induced reduction in the mRNA expression level of hypoxia-inducible factor (HIF)-1α was significantly recovered by arctigenin. The antagonizing effect of arctigenin on UVA irradiation was mediated by reduced PGE₂ production through the inhibition of MAPKs (p42/44 MAPK, p38 MAPK, and JNK) and NF-κB. Overall, these findings suggest that arctigenin can ameliorate the reduced stemness of hMSCs induced by UVA irradiation. The effects of arctigenin are mediated by PGE₂-cAMP signaling-dependent upregulation of HIF-1α. Therefore, arctigenin could be used as an antagonist to attenuate the effects of UVA irradiation.

Neuroprotective effect of arctigenin against neuroinflammation and oxidative stress induced by rotenone

Background: the present study was to investigate the neuroprotective effect of arctigenin, the major active component of a traditional Chinese medicine “Arctii Fructus”, against PD in a rat model induced by rotenone. Materials and methods: in the present study, rotenone was injected subcutaneously in the backs of rats to mimic the progressive neurodegenerative nature of PD and arctigenin was administered. Behavioral analyses including a grid test, bar test and open-field test were used to evaluate motor activities and behavioral movement abilities. Energy metabolism indexes including oxygen consumption, carbon dioxide production, heat production and energy expenditure were measured via a TSE phenoMaster/LabMaster animal monitoring system. Immunohistochemistry was performed to detect the staining of TH and the expression of α-synuclein in substantia nigra (SN). The effect of arctigenin on oxidative stress was evaluated by the levels of GSH and MDA, and activities of SOD and GSH-Px. The levels of pro-inflammatory cytokines such as IL-6, IL-1β, TNF-α, IFN-γ and PGE2, the expression of Iba-1 and GFAP, and the impression of inflammatory mediators such as COX-2 and NF-κB in the SN were measured to evaluate the effect on the inflammation of SN area induced by rotenone. Results: compared with the ROT group, the deadlock time of rats treated with arctigenin was significantly shortened and the score of locomotor activity increased in the behavioral test; the number of TH⁺ positive DA neurons of the arctigenin treated group was increased and α-synuclein immunopositive was decreased; the level of GSH and activities of SOD and GSH-Px in the arctigenin-treated group were significantly increased; arctigenin administration induced a significant decrease in the MDA level; arctigenin also significantly decreased the levels of IL-6, IL-1β, TNF-α, IFN-γ and PGE2 and reduced the impression of COX-2 and NF-κB in SN; treatment with arctigenin decreased microglia and astrocyte activation evidenced by the reduced expression of Iba-1 and GFAP. Conclusion: the findings demonstrated that arctigenin can improve the behavior changes of PD rats and the damage of DA neurons. The oxidative stress and inflammation involved in the pathogenesis of PD and arctigenin may protect DA neurons through its potent antioxidant and anti-inflammatory activities.

The present study was to investigate the neuroprotective effect of arctigenin, the major active component of a traditional Chinese medicine “Arctii Fructus”, against PD in a rat model induced by rotenone.

Arctigenin improves vascular tone and decreases inflammation in human saphenous vein

The goal of this study was to test the effects of bioactive phenylpropanoid dibenzylbutyrolactone lignan arctigenin (ATG) in vascular tone. Human bypass graft vessel, from a saphenous vein (SV), were set up in organ bath system and contracted with potassium chloride (KCl, 40mM). Two concentration-response curves of noradrenaline (NE) (10nM-100μM) separated with an incubation period of 30min without (Control) or with ATG (3-100μM) were established. Inhibitors of nitric oxide, prostaglandins, K⁺ related channels or calcium influx were used to delineate the molecular mechanisms beyond ATG effects. To investigate anti-inflammatory actions, SV were treated with 10μM or 100μM ATG and incubated for 18h in the absence or presence of both interleukin-1beta (IL-1β) and lipopolysaccharide (LPS) to mimic the physiological or inflamed tissue conditions. Proatherogenic and inflammatory mediators İnterleukine-1 beta (IL-1β), Monocyte Chemoattractant Proteine-1 (MCP-1), Tumor Necrosis Factor- α (TNF-α), İnterleukine-6 (IL-6), Prostaglandin E₂ (PGE₂) and İnterleukine-8 (IL-8) in the supernatant were measured. ATG significantly decreased vascular contractile response to NE. Moreover, it reduced contractions induced by KCl and cumulative addition of CaCl_2. The mediators were significantly increased in inflammatory conditions compared to normal conditions, an effect which was inhibited by ATG (10 and 100µM). ATG reduces contractions in SV and decreases the production of proinflammatory-proatherogenic mediators, setting the stage for further evaluating the effect of ATG in cardiovascular diseases.

Biodistribution of arctigenin-loaded nanoparticles designed for multimodal imaging

BACKGROUND

Tracking targets of natural products is one of the most challenging issues in fields ranging from pharmacognosy to biomedicine. It is widely recognized that the biocompatible nanoparticle (NP) could function as a "key" that opens the target "lock".

RESULTS

We report a functionalized poly-lysine NP technique that can monitor the target protein of arctigenin (ATG) in vivo non-invasively. The NPs were synthesized, and their morphologies and surface chemical properties were characterized by transmission electron microscopy (TEM), laser particle size analysis and atomic force microscopy (AFM). In addition, we studied the localization of ATG at the level of the cell and the whole animal (zebrafish and mice). We demonstrated that fluorescent NPs could be ideal carriers in the development of a feasible method for target identification. The distributions of the target proteins were found to be consistent with the pharmacological action of ATG at the cellular and whole-organism levels.

CONCLUSIONS

The results indicated that functionalized poly-lysine NPs could be valuable in the multimodal imaging of arctigenin.

Protective effect of arctigenin on ethanol-induced neurotoxicity in PC12 cells

As a neurotropic substance, ethanol can damage nerve cells through an increase in the production of free radicals, interference of neurotrophic factor signaling pathways, activation of endogenous apoptotic signals and other molecular mechanisms. Previous studies have revealed that a number of natural drugs extracted from plants offer protection of nerve cells from damage. Among these, arctigenin (ATG) is a lignine extracted from Arctium lappa (L.), which has been found to exert a neuroprotective effect on scopolamine‑induced memory deficits in mice with Alzheimer's disease and glutamate-induced neurotoxicity in primary neurons. As a result, it may offer beneficial effects on ethanol-induced neurotoxicity. However, the effects of ATG on ethanol‑induced nerve damage remain to be elucidated. To address this issue, the present study used rat pheochromocytoma PC12 cells to investigate the neuroprotective effects of ATG on ethanol-induced cell damage by performing an MTT reduction assay, cell cycle analysis, Hoechst33342/propidium iodide fluorescence staining and flow cytometry to examine apoptosis. The results showed that 10 µM ATG effectively promoted the proliferation of damaged cells, and increased the distribution ratio of the cells at the G2/M and S phases (P<0.05). In addition, the apoptosis and necrosis of the PC12 cells were significantly decreased following treatment with ATG. Therefore, it was concluded that 10 µM ATG had a protective effect on ethanol‑induced injury in PC12 cells.

The Synthesis and Evaluation of Arctigenin Amino Acid Ester Derivatives

The use of arctigenin (ARG), a traditional medicine with many pharmacological activities, has been restricted due to its poor solubility in water. Five amino acid derivatives of ARG have been synthesized using glycine, o-alanine, valine, leucine, and isoleucine, which have t-butyloxy carbonyl (BOC) as a protective group. In this study, we examined the effects of removing these protective groups. The results showed that the amino acid derivatives have better solubility and nitrite-clearing ability than ARG. Among the compounds tested, the amino acid derivatives without protective group were the best. Based on these results, ARG and its two amino acid derivatives without protective group (ARG8, ARG10) were selected to evaluate their anti-tumor activity in vivo at a dosage of 40 mg/kg. The results indicated that ARG8 and ARG10 both exhibit more anti-tumor activity than ARG in H₂₂ tumor-bearing mice. The tumor inhibition rates of ARG8 and ARG10 were 69.27 and 43.58%, which was much higher than ARG. Furthermore, the mice treated with these compounds exhibited less damage to the liver, kidney and immune organs compared with the positive group. Furthermore, ARG8 and ARG10 improved the serum cytokine levels significantly compared to ARG. In brief, this study provides a method to improve the water solubility of drugs, and we also provide a reference basis for new drug development.

The antiviral activity of arctigenin in traditional Chinese medicine on porcine circovirus type 2

Arctigenin (ACT) is a phenylpropanoid dibenzylbutyrolactone lignan extracted from the traditional herb Arctium lappa L. (Compositae) with anti-viral and anti-inflammatory effects. Here, we investigated the antiviral activity of ACT found in traditional Chinese medicine on porcine circovirus type 2 (PCV2) in vitro and in vivo. Results showed that dosing of 15.6-62.5μg/mL ACT could significantly inhibit the PCV2 proliferation in PK-15 cells (P<0.01). Dosing of 62.5μg/mL ACT 0, 4 or 8h after challenge inoculation significantly inhibited the proliferation of 1MOI and 10MOI in PK-15 cells (P<0.01), and the inhibitory effect of ACT dosing 4h or 8h post-inoculation was greater than 0h after dosing (P<0.01). In vivo test with mice challenge against PCV2 infection demonstrated that intraperitoneal injection of 200μg/kg ACT significantly inhibited PCV2 proliferation in the lungs, spleens and inguinal lymph nodes, with an effect similar to ribavirin, demonstrating the effectiveness of ACT as an antiviral agent against PCV2 in vitro and in vivo. This compound, therefore, may have the potential to serve as a drug for protection of pigs against the infection of PCV2.

Benzofuranyl Esters: Synthesis, Crystal Structure Determination, Antimicrobial and Antioxidant Activities

A series of five new 2-(1-benzofuran-2-yl)-2-oxoethyl 4-(un/substituted)benzoates 4(a-e), with the general formula of C₈H₅O(C=O)CH₂O(C=O)C₆H₄X, X = H, Cl, CH₃, OCH₃ or NO₂, was synthesized in high purity and good yield under mild conditions. The synthesized products 4(a-e) were characterized by FTIR, ¹H-, (13)C- and ¹H-(13)C HMQC NMR spectroscopic analysis and their 3D structures were confirmed by single-crystal X-ray diffraction studies. These compounds were screened for their antimicrobial and antioxidant activities. The tested compounds showed antimicrobial ability in the order of 4b < 4a < 4c < 4d < 4e and the highest potency with minimum inhibition concentration (MIC) value of 125 µg/mL was observed for 4e. The results of antioxidant activities revealed the highest activity for compound 4e (32.62% ± 1.34%) in diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, 4d (31.01% ± 4.35%) in ferric reducing antioxidant power (FRAP) assay and 4a (27.11% ± 1.06%) in metal chelating (MC) activity.

Natural products and synthetic compounds as immunomodulators

Research on immunomodulation by natural products or synthetic derivatives is of key interest for anti-infective therapy for a number of reasons. Many plant remedies well-known in traditional medicine or refined natural products in clinical use exert their anti-infective effects not only (if at all) by directly affecting the pathogen. At least part of their effect is indirect, by stimulating natural and adaptive defense mechanisms of the host. These findings have now given many empirical therapies a rationale, scientific basis and thereby a means for 'intelligent' improvement. In discovering the molecular mechanisms by which known remedies exert their effects, chosen elements further down the 'chain of command' might be synthesized and applied directly for more rapid and selective cure, omitting unwanted side effects. The direct use of recombinant cytokines, often in combination with antibiotics, is one consequence of this rationale.

Arctigenin anti-tumor activity in bladder cancer T24 cell line through induction of cell-cycle arrest and apoptosis

Bladder cancer is the most common neoplasm in the urinary system. This study assesses arctigenin anti-tumor activity in human bladder cancer T24 cells in vitro and the underlying molecular events. The flow cytometry analysis was used to detect cell-cycle distribution and apoptosis. Western blotting was used to detect changes in protein expression. The data showed that arctigenin treatment reduced viability of bladder cancer T24 cells in a dose- and time-dependent manner after treatment with arctigenin (10, 20, 40, 80, and 100 μmol/L) for 24 hr and 48 hr. Arctigenin treatment clearly arrested tumor cells in the G1 phase of the cell cycle. Apoptosis was detected by hoechst stain and flow cytometry after Annexin-V-FITC/PI double staining. Early and late apoptotic cells were accounted for 2.32-7.01% and 3.07-7.35%, respectively. At the molecular level, arctigenin treatment decreased cyclin D1 expression, whereas CDK4 and CDK6 expression levels were unaffected. Moreover, arctigenin selectively altered the phosphorylation of members of the MAPK superfamily, decreasing phosphorylation of ERK1/2 and activated phosphorylation of p38 significantly in a dose-dependent manner. These results suggest that arctigenin may inhibit cell viability and induce apoptosis by direct activation of the mitochondrial pathway, and the mitogen-activated protein kinase pathway may play an important role in the anti-tumor effect of arctigenin. The data from the current study demonstrate the usefulness of arctigenin in bladder cancer T24 cells, which should further be evaluated in vivo before translation into clinical trials for the chemoprevention of bladder cancer.

Immunomodulatory effect of (--)-matairesinol in vivo and ex vivo

Matairesinol is one of the lignan compounds found in a variety of plant foodstuffs. We investigated the immunomodulatory effects of (-)-matairesinol in vivo and ex vivo by using mice. Although we found no significant differences in the IgG, IgA and IgM levels in the serum, the IgE level was strongly suppressed by the uptake of (-)-matairesinol in both intact and ovalbumin-immunized mice. The immunoglobulin produced by lymphocytes from the spleen was not activated by the intake of (-)-matairesinol. However, lymphocytes in such gut-associated lymphatic tissues as Peyer's patches and mesenteric lymph nodes were activated by the administration of (-)-matairesinol.

In vitro anti-inflammatory effects of arctigenin, a lignan from Arctium lappa L., through inhibition on iNOS pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Arctigenin, a bioactive constituent from dried seeds of Arctium lappa L. (Compositae) which has been widely used as a Traditional Chinese Medicine for dispelling wind and heat included in Chinese Pharmacophere, was found to exhibit anti-inflammatory activities but its molecular mechanism remains unknown yet.

AIM OF THE STUDY

To investigate the anti-inflammatory mechanism of arctigenin.

MATERIALS AND METHODS

Cultured macrophage RAW 264.7 cells and THP-1 cells were used for the experiments. Griess assay was used to evaluate the inhibitory effect of arctigenin on the overproduction of nitric oxide (NO). ELISA was used to determine the level of pro-inflammatory cytokines including tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6). The inhibitory effect on the enzymatic activity of cyclooxygenase-2 (COX-2) was tested by colorimetric method. Western blot was used to detect the expression of inducible nitric oxide synthase (iNOS) and COX-2.

RESULTS

Arctigenin suppressed lipopolysaccharide (LPS)-stimulated NO production and pro-inflammatory cytokines secretion, including TNF-alpha and IL-6 in a dose-dependent manner. Arctigenin also strongly inhibited the expression of iNOS and iNOS enzymatic activity, whereas the expression of COX-2 and COX-2 enzymatic activity were not affected by arctigenin.

CONCLUSIONS

These results indicated that potent inhibition on NO, TNF-alpha and IL-6, but not COX-2 expression and COX-2 activity, might constitute the anti-inflammatory mechanism of arctigenin. Arctigenin suppressed the overproduction of NO through down-regulation of iNOS expression and iNOS enzymatic activity in LPS-stimulated macrophage.

[Interest of lignans in prevention and treatment of cancers]

Lignans are diphenolic compounds widely distributed in the plant kingdom. They are mainly localised in lignified tissues, seeds and roots. These molecules are involved in plant defence mechanisms, but are also interesting for human health. Flax lignans belonging to the phytoestrogens are metabolised after ingestion into enterolignans that may offer a protection against the onset and development of hormono-dependant cancers. In vitro studies based on mammalian cellular models tend to confirm their beneficial effects observed during epidemiological studies and give us insights about their mechanisms of action. The most studied lignan, podophyllotoxin, and its semi-synthetic derivatives (etoposide, teniposide, etoposide phosphate), are particularly interesting at a curative level due to their cytotoxic properties. These semi-synthetic derivatives are used in chemotherapy of lung cancer for example. However, the extensive use of these anticancer drugs will lead to the problem of podophyllotoxin supply. This molecule is currently extracted from the rhizomes and roots of an Indian species Podophyllum hexandrum which has subsequently become endangered. Strategies are investigated to obtain economically viable alternative sources of Podophyllotoxin from plants and in vitro cultures of several species. Among them, north american Podophyllum peltatum, Linum wild species, Hyptis, Anthriscus, Juniperus or Dysosma species which accumulate Podophyllotoxin or closely related derivatives, are good candidates. double dagger.

Diarctigenin, a lignan constituent from Arctium lappa, down-regulated zymosan-induced transcription of inflammatory genes through suppression of DNA binding ability of nuclear factor-kappaB in macrophages

Diarctigenin was previously isolated as an inhibitor of nitric oxide (NO) production in macrophages from the seeds of Arctium lappa used as an alternative medicine for the treatment of inflammatory disorders. However, little is known about the molecular basis of these effects. Here, we demonstrated that diarctigenin inhibited the production of NO, prostaglandin E(2), tumor necrosis factor-alpha, and interleukin (IL)-1beta and IL-6 with IC(50) values of 6 to 12 miciroM in zymosan- or lipopolysaccharide-(LPS) activated macrophages. Diarctigenin attenuated zymosan-induced mRNA synthesis of inducible NO synthase (iNOS) and also inhibited promoter activities of iNOS and cytokine genes in the cells. Because nuclear factor (NF)-kappaB plays a pivotal role in inflammatory gene transcription, we next investigated the effect of diarctigenin on NF-kappaB activation. Diarctigenin inhibited the transcriptional activity and DNA binding ability of NF-kappaB in zymosan-activated macrophages but did not affect the degradation and phosphorylation of inhibitory kappaB (IkappaB) proteins. Moreover, diarctigenin suppressed expression vector NF-kappaB p65-elicited NF-kappaB activation and also iNOS promoter activity, indicating that the compound could directly target an NF-kappa-activating signal cascade downstream of IkappaB degradation and inhibit NF-kappaB-regulated iNOS expression. Diarctigenin also inhibited the in vitro DNA binding ability of NF-kappaB but did not affect the nuclear import of NF-kappaB p65 in the cells. Taken together, diarctigenin down-regulated zymosan- or LPS-induced inflammatory gene transcription in macrophages, which was due to direct inhibition of the DNA binding ability of NF-kappaB. Finally, this study provides a pharmacological potential of diarctigenin in the NF-kappaB-associated inflammatory disorders.

Trypanocidal structure-activity relationship for cis- and trans-methylpluviatolide

The trypanocidal activity of racemic mixtures of cis- and trans-methylpluviatolides was evaluated in vitro against trypomastigote forms of two strains of Trypanosoma cruzi, and in the enzymatic assay of T. cruzi gGAPDH. The cytotoxicity of the compounds was assessed by the MTT method using LLC-MK2 cells. The effect of the compounds on peroxide and NO production were also investigated. The mixture of the trans stereoisomers displayed trypanocidal activity (IC50 approximately 89.3 microM). Therefore, it was separated by chiral HPLC, furnishing the (+) and (-)-enantiomers. Only the (-)-enantiomer was active against the parasite (IC50 approximately 18.7 microM). Despite being inactive, the (+)-enantiomer acted as an antagonistic competitor. Trans-methylpluviatolide displayed low toxicity for LLC-MK2 cells, with an IC50 of 6.53 mM. Furthermore, methylpluviatolide neither inhibited gGAPDH activity nor hindered peroxide and NO production at the evaluated concentrations.

(-)-Syringaresinol inhibits proliferation of human promyelocytic HL-60 leukemia cells via G1 arrest and apoptosis

We examined the effect of (-)-syringaresinol, a furofuran-type lignan isolated from Daphne genkwa, on cell cycle regulation in HL-60 human promyelocytic leukemia cells in vitro. (-)-Syringaresinol decreased the viability of HL-60 cells by inducing G(1) arrest followed by apoptosis in a dose- and time-dependent manner. The G(0)/G(1) phase of the cell cycle is regulated by cyclin-dependent kinases (Cdk), cyclins and cyclin-dependent kinase inhibitors (Cdki). We show by western blot analysis, that the (-)-syringaresinol-induced G(1) arrest was mediated through the increased expression of Cdki proteins (p21(cip1/waf1) and p27(kip1)) with a simultaneous decrease in cdk2, cdk4, cdk6, cyclin D(1), cyclin D(2), and cyclin E expression. The induction of apoptosis after treatment with (-)-syringaresinol for 24 h was demonstrated by morphological changes, DNA fragmentation, altered ratio of Bax/Bcl-2, cleavage of poly(ADP-ribose) polymerase and flow cytometry analysis. (-)-Syringaresinol also induced cytochrome c release and activation of caspase-3 and caspase-9. To our knowledge, this is the first time that (-)-syringaresinol has been reported to potently inhibit the proliferation of human promyelocytic HL-60 cells through G(1) arrest and induction of apoptosis. These findings suggest that (-)-syringaresinol may be a potential chemotherapeutic agent for the treatment of cancer.

Taiwanin A induced cell cycle arrest and p53-dependent apoptosis in human hepatocellular carcinoma HepG2 cells

Taiwanin A, a lignan isolated from Taiwania cryptomerioides Hayata, has previously been reported to have cytotoxicity against human tumor cells, but the mechanisms are unclear. In this study, we examined the molecular mechanism of cell death of human hepatocellular carcinoma HepG2 cells induced by Taiwanin A. Taiwanin A has been found to induce cell cycle arrest at G2/M phase as well as caspase-3-dependent apoptosis within 24 h. We performed both in vitro turbidity assay and immunofluorescence staining of tubulin to show that Taiwanin A can inhibit microtubule assembly. Moreover, the tumor suppressor protein p53 in HepG2 cells was activated by Taiwanin A within 12 h. Inhibition of p53 by either pifithrin-alpha or by short hairpin RNA which blocks p53 expression attenuates Taiwanin A cytotoxicity. Our results demonstrate that Taiwanin A can act as a new class of microtubule damaging agent, arresting cell cycle progression at mitotic phase and inducing apoptosis through the activation of p53.

Lignans from Arctium lappa and Their Inhibition of LPS-Induced Nitric Oxide Production

A new butyrolactone sesquilignan, isolappaol C (1), together with four known lignans, lappaol C (2), lappaol D (3), lappaol F (4), and diarctigenin (5), were isolated from the methanolic extract of the seeds from the Arctium lappa plant. The structure of isolappaol C (1) was determined by spectral analysis including 1D- and 2D-NMR. All the isolates were evaluated for their inhibitory effects on the LPS-induced nitric oxide production using murine macrophage RAW264.7 cells. Lappaol F (4) and diarctigenin (5) strongly inhibited NO production in the LPS-stimulated RAW264.7 cells with IC(50) values of 9.5 and 9.6 microM, respectively.

Cytotoxic activity and cytostatic mechanism of novel 2-arylbenzo[b]furans

The aims of this study were to screen cytotoxic compounds from 14 newly-synthesized 2-arylbenzo[b]furans and explore their mechanisms of action. Cytotoxicity was determined by the MTT method. Cell-cycle distribution was detected by flow cytometry. Wright-Giemsa staining was performed to demonstrate the morphological features of cells in mitotic phase. Polymerization of tubulin was detected by tubulin assembly assay, and the cellular microtubule network was observed by immunocytochemical study. Among the 14 compounds screened, 4-formyl-2-(4-hydroxy-3-methoxyphenyl)-5-(2-methoxycarbonyethyl)-7-methoxy-benzo[b]furan (ERJT-12) showed significant cytotoxicity. Our results demonstrated that ERJT-12 exhibited anti-cancer activity in a variety of tumour cell lines with an IC50 value (concentration resulting in 50% inhibition of cell growth) of 5.75 approximately 17.29 microM. Cell cycle analysis showed a concentration-dependent accumulation of tumour cells in G2/M phase after treatment with ERJT-12. Further investigation indicated that ERJT-12 blocked the cell cycle in M phase, with separation and dispersion of chromosomes. ERJT-12 inhibited tubulin polymerization in-vitro. Changes of the cellular microtubule network caused by ERJT-12 were also detected, which were similar to the changes caused by colchicine. These results suggested that the anti-cancer activity of ERJT-12 is worth further investigation.

Bioavailability of lignans in human subjects

Dietary lignans are phyto-oestrogens that possibly influence human health. The present review deals with lignan bioavailability, the study of which is crucial to determine to what extent metabolism, absorption and excretion of lignans alter their biological properties. Since intestinal bacteria play a major role in lignan conversion, for instance by producing the enterolignans enterodiol and enterolactone, emphasis is put on data obtained in recent bacteriological studies.

Identification of arctigenin as an antitumor agent having the ability to eliminate the tolerance of cancer cells to nutrient starvation

Tumor cells generally proliferate rapidly and the demand for essential nutrients as well as oxygen always exceeds the supply due to the unregulated growth and the insufficient and inappropriate vascular supply. However, cancer cells show an inherent ability to tolerate extreme conditions, such as that characterized by low nutrient and oxygen supply, by modulating their energy metabolism. Thus, targeting nutrient-deprived cancer cells may be a novel strategy in anticancer drug development. Based on that, we established a novel screening method to discover anticancer agents that preferentially inhibit cancer cell viability under the nutrient-deprived condition. After screening 500 medicinal plant extracts used in Japanese Kampo medicine, we found that a CH(2)Cl(2)-soluble extract of Arctium lappa exhibited 100% preferential cytotoxicity under the nutrient-deprived condition at a concentration of 50 microg/mL with virtually no cytotoxicity under nutrient-rich condition. Further bioassay-guided fractionation and isolation led to the isolation of arctigenin as the primary compound responsible for such preferential cytotoxicity; the compound exhibited 100% preferential cytotoxicity against nutrient-deprived cells at a concentration of 0.01 microg/mL. Furthermore, arctigenin was also found to strongly suppress the PANC-1 tumor growth in nude mice, as well as the growth of several of the tested pancreatic cancer cell lines, suggesting the feasibility of this novel antiausterity approach in cancer therapy. Further investigation of the mechanism of action of arctigenin revealed that the compound blocked the activation of Akt induced by glucose starvation, which is a key process in the tolerance exhibited by cancer cells to glucose starvation.

A preparative isolation and purification of arctigenin and matairesinol fromForsythia koreana by centrifugal partition chromatography

Centrifugal partition chromatography was applied to separate arctigenin and matairesinol from Forsythia koreana extract with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (5:5:5:5 v/v). Using this method, arctigenin and matairesinol were successfully separated from partially purified F. koreana extracts in only one step. The purities of isolated compounds were determined to be over 90% by HPLC analysis.

Synthesis of 2,3-disubstituted benzo[b]furans by the palladium-catalyzed coupling of o-iodoanisoles and terminal alkynes, followed by electrophilic cyclization

[reaction: see text] 2,3-Disubstituted benzo[b]furans are readily prepared under very mild reaction conditions by the palladium/copper-catalyzed cross-coupling of various o-iodoanisoles and terminal alkynes, followed by electrophilic cyclization with I2, PhSeCl, or p-O2NC6H4SCl. Aryl- and vinylic-substituted alkynes undergo electrophilic cyclization in excellent yields. Biologically important furopyridines can be prepared by this approach in high yields.