Anti-oxidant and anti-inflammatory activities of macelignan in murine hippocampal cell line and primary culture of rat microglial cells

Neuroprotective Effects of Noncanonical PAR1 Agonists on Cultured Neurons in Excitotoxicity

Serine proteases regulate cell functions through G protein-coupled protease-activated receptors (PARs). Cleavage of one peptide bond of the receptor amino terminus results in the formation of a new N-terminus ("tethered ligand") that can specifically interact with the second extracellular loop of the PAR receptor and activate it. Activation of PAR1 by thrombin (canonical agonist) and activated protein C (APC, noncanonical agonist) was described as a biased agonism. Here, we have supposed that synthetic peptide analogs to the PAR1 tethered ligand liberated by APC could have neuroprotective effects like APC. To verify this hypothesis, a model of the ischemic brain impairment based on glutamate (Glu) excitotoxicity in primary neuronal cultures of neonatal rats has been used. It was shown that the nanopeptide NPNDKYEPF-NH2 (AP9) effectively reduced the neuronal death induced by Glu. The influence of AP9 on cell survival was comparable to that of APC. Both APC and AP9 reduced the dysregulation of intracellular calcium homeostasis in cultured neurons induced by excitotoxic Glu (100 µM) or NMDA (200 µM) concentrations. PAR1 agonist synthetic peptides might be noncanonical PAR1 agonists and a basis for novel neuroprotective drugs for disorders related to Glu excitotoxicity such as brain ischemia, trauma and some neurodegenerative diseases.

Phytoconstituents and Ergosterol Biosynthesis-Targeting Antimicrobial Activity of Nutmeg (Myristica fragans Houtt.) against Phytopathogens

In recent years, nutmeg (Myristica fragans Houtt.) has attracted considerable attention in the field of phytochemistry due to its diverse array of bioactive compounds. However, the potential application of nutmeg as a biorational for crop protection has been insufficiently explored. This study investigated the constituents of a nutmeg hydroethanolic extract via gas chromatography-mass spectrometry and vibrational spectroscopy. The research explored the extract's activity against phytopathogenic fungi and oomycetes, elucidating its mechanism of action. The phytochemical profile revealed fatty acids (including tetradecanoic acid, 9-octadecenoic acid, n-hexadecanoic acid, dodecanoic acid, and octadecanoic acid), methoxyeugenol, and elemicin as the main constituents. Previously unreported phytochemicals included veratone, gelsevirine, and montanine. Significant radial growth inhibition of mycelia was observed against Botrytis cinerea, Colletotrichum acutatum, Diplodia corticola, Phytophthora cinnamomi, and especially against Fusarium culmorum. Mode of action investigation, involving Saccharomyces cerevisiae labeled positively with propidium iodide, and a mutant strain affected in ERG6, encoding sterol C-24 methyltransferase, suggested that the extract induces a necrotic type of death and targets ergosterol biosynthesis. The evidence presented underscores the potential of nutmeg as a source of new antimicrobial agents, showing particular promise against F. culmorum.

Macelignan prevents colorectal cancer metastasis by inhibiting M2 macrophage polarization

BACKGROUND

Colorectal cancer (CRC) metastasis is a complicated process that not only involves tumor cells but also the effects of M2 type tumor-associated macrophages, a key component of the tumor microenvironment (TME), act a crucial role in cancer metastasis. Macelignan, an orally active lignan isolated from Myristica fragrans, possesses various beneficial biological activities, including anti-cancer effects, but its effect on macrophage polarization in the TME remains unknown.

PURPOSE

To evaluate the inhibitory potency and prospective mechanism of macelignan on M2 polarization of macrophages and CRC metastasis.

METHODS

The polarization and specific mechanism of M1 and M2 macrophage regulated by macelignan were determined by western blot, flow cytometry, immunofluorescence and network pharmacology. In vitro and in vivo function assays were performed to investigate the roles of macelignan in CRC metastasis.

RESULTS

Macelignan efficiently inhibited IL-4/13-induced polarization of M2 macrophages by suppressing the PI3K/AKT pathway in a reactive oxygen species (ROS)-dependent manner. The proportion of CD206+ M2 macrophages was elevated in patients with CRC liver metastasis. Furthermore, macelignan inhibited M2 macrophage-mediated metastasis of CRC cells in vitro and in vivo. Mechanistically, macelignan reduced secretion of IL-1β from M2 macrophages, which in turn blocked NF-κB p65 nuclear translocation and inhibited metastasis.

CONCLUSION

Macelignan suppressed macrophage M2 polarization via ROS-mediated PI3K/AKT signaling pathway, thus preventing IL-1β/NF-κB-dependent CRC metastasis. In the present study, we reveal a previously unrecognized mechanism of macelignan in the prevention of CRC metastasis and demonstrate its effectively and safely therapeutic potential in CRC treatment.

Treatment of polycystic ovary syndrome and its associated psychiatric symptoms with the Mongolian medicine Nuangong Qiwei Pill and macelignan

ETHNOPHARMACOLOGICAL RELEVANCE

The Mongolian medicine Nuangong Qiwei Pill (NGQW) is a folk prescription with a long history of use by the Mongolian people. NGQW comprises seven Mongolian medicines, which have the effects of regulating and nourishing blood, warming the uterus, dispelling cold and relieving pain. For a long time, it has been used as a good remedy for gynecological diseases, with remarkable curative effects, favored by the majority of patients and recommended by doctors. Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disorder that can lead to menstrual disorders or infertility. In the gynecological classification of Mongolian medicine, polycystic ovary syndrome has not been distinguished in detail, and the mechanism of NGQW in the treatment of polycystic ovary syndrome has not been scientifically studied and standardized.

AIM OF THE STUDY

The aim of this study was to clarify the mechanism of action of NGQW and macelignan in the treatment of PCOS and to provide a reference for the clinical application of these drugs.

MATERIALS AND METHODS

The effect of intragastric administration of NGQW and macelignan on PCOS model mice was observed. The mental status of mice was examined behaviorally, and serum hormone levels and oxidative stress parameters were measured by ELISA. Giemsa staining was used to detect the reproductive cycle, and HE staining was used to observe the ovarian status. Immunofluorescence staining was performed to observe the proliferation and apoptosis of ovarian granulosa cells. qRT‒PCR was conducted to measure the expression of IL-6, BAX, BCL-2, and estrogen synthesis-related genes in ovarian tissue and particle cells.

RESULTS

In the dehydroepiandrosterone (DHEA)-induced PCOS model mice, both NGQW and macelignan improved the estrous cycle; increased the estradiol (E2) content; lowered testosterone (T), progesterone (P) and luteinizing hormone (LH) levels; reduced the number of polycystic follicles; promoted granulosa cell proliferation; reduced granulosa cell apoptosis; and alleviated depression and anxiety. In addition, Nuangong Qiwei Pill and macelignan reduced the mRNA levels of the ovarian inflammatory factor IL-6; improved the disordered levels of the antioxidant indicators GSH, MDA, and SOD; and activated the TGF-β3 signaling pathway to increase the transcription of Cyp19a1, which increases estrogen secretion.

CONCLUSION

NGQW and macelignan can treat PCOS through the TGF-β3/Smad/Cyp19a1 signaling pathway to regulate the secretion ability of ovarian granulosa cells. Our research justifies the traditional use of NGQW to treat PCOS and enriches the scope of action of macelignan.

Inhibition of LPS-Induced Microglial Activation by the Ethyl Acetate Extract of Pueraria mirifica

Microglial activation has been found to play a crucial role in various neurological disorders. Proinflammatory substances overproduced by activated microglia, such as cytokines, chemokines, reactive oxygen species, and nitric oxide (NO), can result in neuroinflammation that further exacerbates the course of the diseases. This study aimed to explore the anti-inflammatory effect of the ethyl acetate extract of Pueraria mirifica on microglial activation. Lipopolysaccharide (LPS)-induced inflammation was used as a model to investigate the effects of P. mirifica on HAPI (highly aggressive proliferating immortalized), a rat microglial cell line. Administration of ethyl acetate extract from the tuberous roots of P. mirifica to HAPI cells dose-dependently reduced NO production and iNOS expression induced by LPS. Attenuation of IRF-1 (interferon regulatory factor-1) induction, one of the transcription factors governing iNOS expression, suggested that the inhibitory effect on NO production by the plant extract was at least partially mediated through this transcription factor. In addition, LPS-stimulated mRNA expression of MCP-1 (monocyte chemoattractant protein-1), IL-6 (interleukin-6), and TNF-α (tumor necrosis factor-α) was also suppressed with P. mirifica extract pretreatment. This study indicates that the ethyl acetate extract of P. mirifica could potentially serve as an anti-inflammatory mediator and may be useful in relieving the severity of neurological diseases where microglia play a role.

Inhibitory Effects of Macelignan on Tau Phosphorylation and Aβ Aggregation in the Cell Model of Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disorder mainly affecting old population. In this study, two Tau overexpressing cell lines (SH-SY5Y/Tau and HEK293/Tau), N2a/SweAPP cell line, and 3× Transgene (APPswe/PS1M146V/TauP301L) mouse primary nerve cell lines were used as AD models to study the activity and molecular mechanism of macelignan, a natural compound extracted from Myristica fragrans, against AD. Our study showed that macelignan could reduce the phosphorylation of Tau at Thr 231 site, Ser 396 site, and Ser 404 site in two overexpressing Tau cell lines. It also could decrease the phosphorylation of Tau at Ser 404 site in mouse primary neural cells. Further investigation of its mechanism found that macelignan could reduce the phosphorylation of Tau by increasing the level of autophagy and enhancing PP2A activity in Tau overexpressing cells. Additionally, macelignan could activate the PERK/eIF2α signaling pathway to reduce BACE1 translation, which further inhibits the cleavage of APP and ultimately suppresses Aβ deposition in N2a/SweAPP cells. Taken together, our results indicate that macelignan has the potential to be developed as a treatment for AD.

Bioactive Based Nanocarriers for the Treatment of Viral Infections and SARS-CoV-2

Since ancient times, plants have been used for their medicinal properties. They provide us with many phytomolecules, which serve a synergistic function for human well-being. Along with anti-microbial, plants also possess anti-viral activities. In Western nations, about 50% of medicines were extracted from plants or their constituents. The spread and pandemic of viral diseases are becoming a major threat to public health and a burden on the financial prosperity of communities worldwide. In recent years, SARS-CoV-2 has made a dramatic lifestyle change. This has promoted scientists not to use synthetic anti-virals, such as protease inhibitors, nucleic acid analogs, and other anti-virals, but to study less toxic anti-viral phytomolecules. An emerging approach includes searching for eco-friendly therapeutic molecules to develop phytopharmaceuticals. This article briefly discusses numerous bioactive molecules that possess anti-viral properties, their mode of action, and possible applications in treating viral diseases, with a special focus on coronavirus and various nano-formulations used as a carrier for the delivery of phytoconstituents for improved bioavailability.

Pharmacokinetics and Tissue Distribution of Anwuligan in Rats after Intravenous and Intragastric Administration by Liquid Chromatography-Mass Spectrometry

Anwuligan, a natural 2,3-dibenzylbutane lignan from the nutmeg mace of Myristica fragans, has been proved to possess a broad range of pharmacological effects. A rapid, simple, and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been established and successfully applied to the study of pharmacokinetics and tissue distribution of anwuligan after intravenous or intragastric administration. Sample preparation was carried out through a liquid-liquid extraction method with ethyl acetate as the extraction reagent. Arctigenin was used as the internal standard (IS). A gradient program was employed with a mobile phase consisting of 0.1% formic acid aqueous solution and acetonitrile. The mass spectrometer was operated in a positive ionization mode with multiple reaction monitoring. The transitions for quantification were m/z 329.0→205.0 for anwuligan and m/z 373.0→137.0 for IS, respectively. Calibration curves were linear over the ranges of 0.5-2000 ng/mL for both plasma samples and tissue samples (r > 0.996). The absolute bioavailability is 16.2%, which represented the existing of the obvious first-pass effect. An enterohepatic circulation was found after the intragastric administration. Anwuligan could be distributed rapidly and widely in different tissues and maintained a high concentration in the liver. The developed and validated LC-MS/MS method and the pharmacokinetic study of anwuligan would provide reference for the future investigation of the preclinical safety of anwuligan as a candidate drug.

Macelignan inhibits the inflammatory response of microglia and regulates neuronal survival

Neuroinflammation is an important pathological process of neurodegenerative diseases, and microglial contributes to chronic inflammation and neuronal loss in progressive neurodegenerative. Therefore, regulating the inflammatory response of microglia could lead to the discovery of promising treatments for neurodegenerative diseases. In this study, we investigated the effects of the nutmeg plant seed extract, macelignan, on the inflammatory response of microglia and neuronal cell survival. We detected NO and iNOS using the Griess test and Western blotting. We measured phosphoinositide 3 kinase (PI3K)/Akt expression by Western blotting. The release of NO and inflammatory cytokines and the expression of iNOS decreased in a concentration-dependent manner, with an increase in macelignan concentration. PI3K/Akt phosphorylation levels decreased in a dose-dependent manner in lipopolysaccharide (LPS)-activated microglial cells after exposure to macelignan. We also demonstrated that macelignan improved HT22 cell viability, following exposure to a microglial-conditioned medium. Furthermore, macelignan inhibited microglial cell near neurons treated with a hypoxic conditioned medium. Finally, macelignan treatment reduced the expression of p27 and cyclin D1 in neurons cultured in an LPS-activated microglia-conditioned medium. Therefore, these results imply that macelignan can inhibit the inflammatory response of microglia and regulate neuronal survival through the PI3K/Akt pathway.

Neuroprotective effects of myristargenol A against glutamate-induced apoptotic HT22 cell death

Glutamate is an important neurotransmitter in the central nervous system; however, at high concentrations, it causes excitotoxicity and many neurological disorders. Excitotoxicity induces cell death by apoptosis. Thus, factors that can inhibit the apoptotic pathways are a target of drug development for the treatment and prevention of neurodegenerative diseases. Herein, the antioxidative and neuroprotective effects of myristargenol A were examined in glutamate-induced mouse hippocampal neuronal HT22 cells. When the HT22 cells were stressed with glutamate, cell viability decreased to 44.4 ± 5.6% when compared with the case of the control cells (100 ± 4.8%); however, when these cells were treated with myristargenol A (10 μM), the cell viability was increased by 113.6 ± 2.3%. The protective effect of myristargenol A against the apoptosis of glutamate-induced HT22 cells was also confirmed using FITC-annexin V/propidium iodide double staining. In addition, myristargenol A protected the mitochondrial membrane potential (ΔΨ m). Subsequently, the expression levels of proteins in the caspase pathway related with the induction of apoptosis were decreased. Moreover, the expression levels of mitochondrial-related proteins, such as Bcl-2 and Bax, were examined, and it was found that the expression ratio of Bax/Bcl-2 decreased. In addition, myristargenol A inhibited the activity of mitogen-activated protein kinases, including p38 and c-Jun N-terminal kinase, for an oxidative stress protection effect but increased the activity of the extracellular signal-regulated kinases 1 and 2 for cell proliferation. These results reveal that myristargenol A possesses a neuroprotective effect against the neuronal cell damage caused by glutamate.

Potent inhibition of acetylcholinesterase by sargachromanol I from Sargassum siliquastrum and by selected natural compounds

Six hundred forty natural compounds were tested for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities. Of those, sargachromanol I (SCI) and G (SCG) isolated from the brown alga Sargassum siliquastrum, dihydroberberine (DB) isolated from Coptis chinensis, and macelignan (ML) isolated from Myristica fragrans, potently and effectively inhibited AChE with IC50 values of 0.79, 1.81, 1.18, and 4.16 µM, respectively. SCI, DB, and ML reversibly inhibited AChE and showed mixed, competitive, and noncompetitive inhibition, respectively, with Ki values of 0.63, 0.77, and 4.46 µM, respectively. Broussonin A most potently inhibited BChE (IC50 = 4.16 µM), followed by ML, SCG, and SCI (9.69, 10.79, and 13.69 µM, respectively). In dual-targeting experiments, ML effectively inhibited monoamine oxidase B with the greatest potency (IC50 = 7.42 µM). Molecular docking simulation suggested the binding affinity of SCI (-8.6 kcal/mol) with AChE was greater than those of SCG (-7.9 kcal/mol) and DB (-8.2 kcal/mol). Docking simulation indicated SCI interacts with AChE at Trp81, and that SCG interacts at Ser119. No hydrogen bond was predicted for the interaction between AChE and DB. This study suggests SCI, SCG, DB, and ML be viewed as new reversible AChE inhibitors and useful lead compounds for the development for the treatment of Alzheimer's disease.

3D tissue engineering, an emerging technique for pharmaceutical research

Tissue engineering and the tissue engineering model have shown promise in improving methods of drug delivery, drug action, and drug discovery in pharmaceutical research for the attenuation of the central nervous system inflammatory response. Such inflammation contributes to the lack of regenerative ability of neural cells, as well as the temporary and permanent loss of function associated with neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and traumatic brain injury. This review is focused specifically on the recent advances in the tissue engineering model made by altering scaffold biophysical and biochemical properties for use in the treatment of neurodegenerative diseases. A portion of this article will also be spent on the review of recent progress made in extracellular matrix decellularization as a new and innovative scaffold for disease treatment.

Total Synthesis of Leoligin from Edelweiss Roots

Leoligin, a tetrahydrofuran lignan isolated from the root of the edelweiss plant, was synthesised from veratraldehyde (2 mol), diethyl succinate and 2-methyl-(Z)-2-butenoic acid. Initially, veratraldehyde and diethyl succinate underwent a Stobbe condensation to yield a C6-C5 acid which, after esterification, was condensed with a second molecule of veratraldehyde to generate a 2,3,4-trisubsituted γ-butyrolactone intermediate. Two reduction steps yielded a triol, which was ring-closed with tosyl chloride to form a hydroxymethyl-tetrahydrofuran, esterification of which with 2-methyl-(Z)-2-butenoic acid generated leoligin.

Therapeutic Effect of Ershen Pill () Extract on Pi (Spleen)-Shen (Kidney) Yang Deficiency-Induced Diarrhea in Rat Model

OBJECTIVE

To investigate whether Ershen Pill (ESP, ) could alleviate the symptom of Pi (Spleen)-Shen (Kidney) yang deficiency (PSYD)-induced diarrhea in rat model and explore its anti-diarrhea mechanism.

METHODS

Seventy-five Sprague-Dawley rats were divided into 5 groups by a random number table, including control, positive, model, low-dose (LD) and high-dose (HD) ESP groups, 15 rats in each group. All the rats, except those in the control group, were developed PSYD induced-diarrhea based on its pathology and etiology. The rats in positive, LD and HD ESP groups were treated with Shenling Baizhu Pill (), LD (1.05 g/kg) or HD (3.50 g/kg) ESP petroleum ether extract once a day for 2 weeks, respectively. Body weight change and diarrhea index were measured. The histology scores of the kidney were evaluated via hematoxylin and eosin (HE) staining. Aquaporin-3 (AQP3) expression in the colon was analyzed by immunofluorescence, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot, respectively.

RESULTS

Compared with the model group, oral administration of LD and HD ESP prevented body weight loss and inhibited diarrhea after 2-week treatment (P<0.05). Kidney deterioration was impeded, and the histology score in LD and HD ESP groups were 8.2 and 10.5, respectively, which were both higher than those in the model group (P<0.05). In addition, ESP treatment alleviated rat colitis, and HD ESP significantly improved the AQP3 positive staining intensity in the colon tissue compared with the model group. The result from Western blot revealed that AQP3 protein synthesis in colon tissue of LD and HD ESP groups increased by 2.1- and 5.9-fold compared with the model group (P<0.05). qRT-PCR result showed that AQP3 gene expression in the HD ESP group was also up-regulated by 2.5-fold normalized to the model group (P<0.05).

CONCLUSION

ESP extract effectively alleviates the symptoms of PSYD and relieves PSYD-induced diarrhea by improving AQP3 synthesis in the colon.

Mucuna pruriens Protects against MPTP Intoxicated Neuroinflammation in Parkinson's Disease through NF-κB/pAKT Signaling Pathways

Till date, drugs that have been used to manage Parkinson’s disease (PD) have only shown symptomatic relief with several adverse effects besides their inability to prevent neurodegeneration. Neuroinflammation plays an important role in the advancement of PD and can be targeted for its effective treatment. Researchers have suggested that herbal plants exhibiting the anti-inflammatory and anti-oxidant properties are therefore beneficial to human health. Conventionally, Mucuna pruriens (Mp) seeds are used for maintaining male virility in India. Reportedly, Mp is used as a rejuvenator drug having neuroprotective property. Our study aimed to investigate effects of aqueous extract of Mp (100 mg/kgbwt) on neuroinflammation, orally administered to mice intoxicated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) as well as the molecular mechanism involved in the progression of PD. In this study, we have observed significant behavioral abnormalities beside decreased antioxidant defense in MPTP intoxicated mice. We have also observed significant increase in inflammatory parameters like Glial Fibrillary Acidic Protein, Inducible Nitric Oxide Synthase, Intercellular Cell Adhesion Molecule, and Tumor Necrosis Factor alpha in substantia nigra pars compacta (SNpc) of parkinsonian mice, while Mp treatment has notably reduced these inflammatory parameters. Mp also inhibited the MPTP induced activation of NF-κB and promoted pAkt1 activity which further prevented the apoptosis of the dopaminergic neurons. Moreover, Mp exhibited significant antioxidant defense by inhibiting the lipid peroxidation and nitrite level, and by improving catalase activity and enhancing GSH level in nigrostriatal region of mouse brain. Mp also recovered the behavioral abnormalities in MPTP treated mice. Additionally, Mp treatment considerably increased the immunoreactivity of Tyrosine Hydroxylase and Dopamine Transporter in SNpc of parkinsonian mice. Our high performance liquid chromatography analysis of the Mp seed extract have shown L-DOPA, gallic acid, phytic acid, quercetin, and catechin equivalents as the major components which might cause neuroprotection in PD mice. Our result suggested that Mp extract treatment containing L-DOPA and a mixture of rich novel phytochemicals significantly alleviates the MPTP induced neurotoxicity by NF-κB and pAkt pathway. The findings observed thereby indicate that Mp extract have suggestively ameliorated MPTP induced neuroinflammation, restored the biochemical and behavioral abnormalities in PD mouse and thus provided a scientific basis for its traditional claim.

Biosynthesis of silver nanoparticles using Myristica fragrans seed (nutmeg) extract and its antibacterial activity against multidrug-resistant (MDR) Salmonella enterica serovar Typhi isolates

Biosynthesis of nanoparticles has received increasing attention due its effective mode of action, eco-friendly preparation methodology, and less cytotoxicity. In the present study, silver nanoparticles (AgNPs) from aqueous seed extract of Myristica fragrans (nutmeg) were characterized. Gas chromatography-mass spectrometry (GC-MS) analysis revealed the presence of bioactive components acts as effective in reducing and capping agents for converting AgNO₃ to AgNPs. The UV-Vis absorption spectrum of the biologically reduced reaction mixture showed the surface plasmon peak at 420 nm, which is the characteristic peak of AgNPs. The functional molecules present in the M. fragrans seed extract and their interaction with the AgNPs were identified by the Fourier transform infrared spectroscopy (FT-IR) analysis. X-ray diffraction (XRD) analysis confirmed the face-centered cubic crystalline structure of metallic silver nanoparticle and diameter was calculated using Scherrer's equation. Transmission electron microscope (TEM) image showed spherical shaped particles with an average size of 25 nm. The scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) confirmed the presence of elemental silver. The antibacterial activity of biosynthesized AgNPs was evaluated against multidrug-resistant (MDR) Salmonella enterica serovar Typhi (S. Typhi) according to agar well diffusion, MIC (minimum inhibitory concentration), and IC₅₀ (inhibitory concentration 50%). The results confirm that bacterial growth was significantly reduced in a dose-dependent manner. Further, the cytotoxic effect of biosynthesized AgNPs on rat spleenocytes was analyzed. Thus, it is suggested that the nutmeg-biosynthesized AgNPs could be a lead drug and used effectively to control the MDR S. Typhi, thereby reducing public health issues and environmental pollution.

Macelignan inhibits bee pathogenic fungi Ascophaera apis growth through HOG1 pathway

Ascosphaera apis is a bee pathogen that causes bee larvae infection disease, to which treatment is not yet well investigated. The aim of this study was to investigate antifungal susceptibility in vitro against A. apis and to identify a new antifungal agent for this pathogen through minimal inhibitory concentration (MIC) assay and western blot analysis. Macelignan had 1.56 and 3.125 μg/mL MIC against A. apis after 24 and 48 h, respectively, exhibiting the strongest growth inhibition against A. apis among the tested compounds (corosolic acid, dehydrocostus lactone, loganic acid, tracheloside, fangchinoline and emodin-8-O-β-D-glucopyranoside). Furthermore, macelignan showed a narrow-ranged spectrum against various fungal strains without any mammalian cell cytotoxicity. In spite of miconazole having powerful broad-ranged anti-fungal activity including A. apis, it demonstrated strong cytotoxicity. Therefore, even if macelignan alone was effective as an antifungal agent to treat A. apis, combined treatment with miconazole was more useful to overcome toxicity, drug resistance occurrence and cost effectiveness. Finally, HOG1 was revealed as a target molecule of macelignan in the anti-A. apis activity by inhibiting phosphorylation using S. cerevisiae as a model system. Based on our results, macelignan, a food-grade antimicrobial compound, would be an effective antifungal agent against A. apis infection in bees.

Neuroprotective compounds from Reynoutria sachalinensis

Glutamate is a neurotransmitter in central nervous system. Overexpression of glutamate leads to oxidative stress, resulting in several neurodegenerative disorders that include Alzheimer's disease. The n-hexane fraction of stems and ethyl acetate (EtOAc) fraction of flowers of Reynoutria sachalinensis provide neuroprotection against glutamate-induced oxidative toxicity in HT22 cells. In this study, 1-decanol (1), β-amyrin (2), dammaran-3β-ol (3), campesterol (4), daucosterol (5), ergosterol peroxide (6), emodin 8-O-β-D-glucopyranoside (7), quercetin (8) and isoquercitrin (9) were isolated from n-hexane fractions of stems and EtOAc fractions of flowers of R. sachalinensis. Their neuroprotective activity was evaluated by MTT assay. 1-Decanol, campesterol, ergosterol peroxide, quercetin and isoquercitrin exhibited neuroprotective activity. These compounds decreased reactive oxygen species level, showed anti-oxidant activity with DPPH radical and in a H₂O₂ scavenging assay. Therefore, the neuroprotective activity of 1-decanol, campesterol, ergosterol peroxide, quercetin and isoquercitrin are associated with antioxidant activity.

Alismol, a Sesquiterpenoid Isolated from Vladimiria souliei, Suppresses Proinflammatory Mediators in Lipopolysaccharide-Stimulated Microglia

Microglia activation plays an important role in the pathogenesis of various neurodegenerative diseases by producing neurotoxic factors, such as proinflammatory cytokines and nitric oxide (NO); therefore, suppression of microglia activation is a potential therapeutic approach against these diseases. Previous study showed that alismol, a sesquiterpenoid isolated from the roots of Vladimiria souliei inhibits interferon-γ-induced NO production in murine macrophage RAW264.7 cells. In the present study, we found that alismol reduced NO and prostaglandin E₂ (PGE₂) levels and suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-stimulated primary and cultured microglia. Alismol also inhibited the mRNA and protein expression of proinflammatory cytokines including interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α. Further mechanistic studies revealed that alismol inhibited LPS-induced nuclear factor-κB (NF-κB) activation but not mitogen-activated protein kinase (MAPK) pathway. Finally, we demonstrated the neuroprotective effects of alismol in microglia-neuron coculture systems. Collectively, these results suggest that the inhibition of microglia activation by alismol may provide potential therapeutic strategy for various neuroinflammatory diseases.

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

Background

Parkinson disease (PD) is a movement disorder affecting 1 % of people over the age of 60. The etiology of the disease is unknown; however, accumulating evidence suggests that mitochondrial defects, oxidative stress, and neuroinflammation play important roles in developing the disease. Current medications for PD can only improve its symptoms, but are unable to halt its progressive nature. Although many therapeutic approaches are available, new drugs are urgently needed for the treatment of PD. Thus, the present study was undertaken to investigate the neuroprotective potential of nerolidol, a sesquiterpene alcohol, on a rotenone-induced experimental model of PD, where male Wistar rats intraperitoneally received rotenone (ROT) at a dose of 2.5 mg/kg of body weight once daily for 4 weeks.

Results

Nerolidol, which has antioxidant and anti-inflammatory properties, was injected intraperitoneally at 50 mg/kg of body weight, once daily for 4 weeks, and at 30 min prior to ROT administration. ROT administration significantly reduced the activities of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), and the level of the antioxidant tripeptide glutathione (GSH). Moreover, ROT increased the levels of the lipid peroxidation product malondialdehyde (MDA), proinflammatory cytokines (IL-1β, IL-6, and TNF-α), and inflammatory mediators (COX-2 and iNOS) in rat brain tissues. Immunostaining of brain tissue sections revealed a significant increase in the number of activated astrocytes (GFAP) and microglia (Iba-1), along with the concomitant loss of dopamine (DA) neurons in the substantia nigra pars compacta and dopaminergic nerve fibers in the striatum of ROT-treated rats. As expected, nerolidol supplementation to ROT-injected rats significantly increased the level of SOD, CAT, and GSH, and decreased the level of MDA. Nerolidol also inhibited the release of proinflammatory cytokines and inflammatory mediators. Finally, nerolidol treatment prevented ROT-induced glial cell activation and the loss of dopaminergic neurons and nerve fibers, and ultimately attenuated ROT-induced dopaminergic neurodegeneration.

Conclusion

Our findings are the first to show that the neuroprotective effect of nerolidol is mediated through its anti-oxidant and anti-inflammatory activities, which strongly supports its therapeutic potential for the treatment of PD.

Inhibition of TYRO3/Akt signaling participates in hypoxic injury in hippocampal neurons

In this study, we investigated the role of the TYRO3/Akt signaling pathway in hypoxic injury to hippocampal neurons. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that hypoxia inhibited the proliferation and viability of hippocampal neurons. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay demonstrated that hypoxia induced neuronal apoptosis in a time-dependent manner, with a greater number of apoptotic cells with longer hypoxic exposure. Immunofluorescence labeling revealed that hypoxia suppressed TYRO3 expression. Western blot assay showed that hypoxia decreased Akt phosphorylation levels in a time-dependent manner. Taken together, these findings suggest that hypoxia inhibits the proliferation of hippocampal neurons and promotes apoptosis, and that the inhibition of the TYRO3/Akt signaling pathway plays an important role in hypoxia-induced neuronal injury.

Anti-Inflammatory and Cytoprotective Effects of TMC-256C1 from Marine-Derived Fungus Aspergillus sp. SF-6354 via up-Regulation of Heme Oxygenase-1 in Murine Hippocampal and Microglial Cell Lines

In the course of searching for bioactive secondary metabolites from marine fungi, TMC-256C1 was isolated from an ethyl acetate extract of the marine-derived fungus Aspergillus sp. SF6354. TMC-256C1 displayed anti-neuroinflammatory effect in BV2 microglial cells induced by lipopolysaccharides (LPS) as well as neuroprotective effect against glutamate-stimulated neurotoxicity in mouse hippocampal HT22 cells. TMC-256C1 was shown to develop a cellular resistance to oxidative damage caused by glutamate-induced cytotoxicity and reactive oxygen species (ROS) generation in HT22 cells, and suppress the inflammation process in LPS-stimulated BV2 cells. Furthermore, the neuroprotective and anti-neuroinflammatory activities of TMC-256C1 were associated with upregulated expression of heme oxygenase (HO)-1 and nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2) in HT22 and BV2 cells. We also found that TMC-256C1 activated p38 mitogen-activated protein kinases (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways in HT22 and BV2 cells. These results demonstrated that TMC-256C1 activates HO-1 protein expression, probably by increasing nuclear Nrf2 levels via the activation of the p38 MAPK and PI3K/Akt pathways.

The Blood-Brain Barrier Permeability of Lignans and Malabaricones from the Seeds of Myristica fragrans in the MDCK-pHaMDR Cell Monolayer Model

The blood-brain barrier (BBB) permeability of twelve lignans and three phenolic malabaricones from the seeds of Myristica fragrans (nutmeg) were studied with the MDCK-pHaMDR cell monolayer model. The samples were measured by high-performance liquid chromatography and the apparent permeability coefficients (P_app) were calculated. Among the fifteen test compounds, benzonfuran-type, dibenzylbutane-type and arylnaphthalene-type lignans showed poor to moderate permeabilities with P_app values at 10⁻⁸–10⁻⁶ cm/s; those of 8-O-4′-neolignan and tetrahydrofuran-lignan were at 10⁻⁶–10⁻⁵ cm/s, meaning that their permeabilities are moderate to high; the permeabilities of malabaricones were poor as their P_app values were at 10⁻⁸–10⁻⁷ cm/s. To 5-methoxy-dehydrodiisoeugenol (2), erythro-2-(4-allyl-2,6-dimethoxyphenoxy)-1-(3,4-dimethoxyphenyl)-propan-1-ol acetate (6), verrucosin (8), and nectandrin B (9), an efflux way was involved and the main transporter for 6, 8 and 9 was demonstrated to be P-glycoprotein. The time and concentration dependency experiments indicated the main transport mechanism for neolignans dehydrodiisoeugenol (1), myrislignan (7) and 8 was passive diffusion. This study summarized the relationship between the BBB permeability and structure parameters of the test compounds, which could be used to preliminarily predict the transport of a compound through BBB. The results provide a significant molecular basis for better understanding the potential central nervous system effects of nutmeg.

Delivery of a protein transduction domain-mediated Prdx6 protein ameliorates oxidative stress-induced injury in human and mouse neuronal cells

Oxidative stress or reduced expression of naturally occurring antioxidants during aging has been identified as a major culprit in neuronal cell/tissue degeneration. Peroxiredoxin (Prdx) 6, a protective protein with GSH peroxidase and acidic calcium-independent phospholipase A2 activities, acts as a rheostat in regulating cellular physiology by clearing reactive oxygen species (ROS) and thereby optimizing gene regulation. We found that under stress, the neuronal cells displayed reduced expression of Prdx6 protein and mRNA with increased levels of ROS, and the cells subsequently underwent apoptosis. Using Prdx6 fused to TAT transduction domain, we showed evidence that Prdx6 was internalized in human brain cortical neuronal cells, HCN-2, and mouse hippocampal cells, HT22. The cells transduced with Prdx6 conferred resistance against the oxidative stress inducers paraquat, H2O2, and glutamate. Furthermore, Prdx6 delivery ameliorated damage to neuronal cells by optimizing ROS levels and overstimulation of NF-κB. Intriguingly, transduction of Prdx6 increased the expression of endogenous Prdx6, suggesting that protection against oxidative stress was mediated by both extrinsic and intrinsic Prdx6. The results demonstrate that Prdx6 expression is critical to protecting oxidative stress-evoked neuronal cell death. We propose that local or systemic application of Prdx6 can be an effective means of delaying/postponing neuronal degeneration.

A natural compound macelignan protects midbrain dopaminergic neurons from inflammatory degeneration via microglial arginase-1 expression

Inflammatory events involving activated microglia have been recognized to play an important role in pathogenesis of various neurodegenerative disorders including Parkinson disease. Compounds regulating activation profiles of microglia may provide therapeutic benefits for Parkinson disease characterized by degeneration of midbrain dopaminergic neurons. Here we examined the effect of macelignan, a compound derived from nutmeg, on inflammatory degeneration of midbrain dopaminergic neurons. Treatment of midbrain slice cultures with interferon (IFN)-γ and lipopolysaccharide (LPS) caused a substantial decrease in viable dopaminergic neurons and an increase in nitric oxide (NO) production indicated by extracellular nitrite accumulation. Application of macelignan (10 μM) concomitantly with LPS prevented the loss of dopaminergic neurons. Besides nitrite accumulation, up-regulation of inducible NO synthase protein expression in response to IFN-γ/LPS was confirmed by Western blotting, and immunohistochemical examination revealed expression of inducible NO synthase in a subpopulation of Iba-1-poitive microglia. However, macelignan did not affect any of these NO-related parameters. On the other hand, macelignan promoted expression of arginase-1 in midbrain slice cultures irrespective of the presence or the absence of IFN-γ/LPS treatment. Arginase-1 expression was mainly localized in a subpopulation of Iba-1-positive cells. Importantly, the neuroprotective effect of macelignan was antagonized by N(ω)-hydroxy-nor-L-arginine, a specific arginase inhibitor. The neuroprotective effect of macelignan was also prevented by GW9662, a peroxisome proliferator-activated receptor γ (PPARγ) antagonist. Overall, these results indicate that macelignan, a compound with PPARγ agonist activity, can provide neuroprotective effect on dopaminergic neurons in an arginase-dependent but NO-independent manner.

Intranasal PRGF-Endoret enhances neuronal survival and attenuates NF-κB-dependent inflammation process in a mouse model of Parkinson's disease

Parkinson's disease is a common neurodegenerative disorder of unknown pathogenesis characterized by the loss of nigrostriatal dopaminergic neurons. Oxidative stress, microglial activation and inflammatory responses seem to contribute to the pathogenesis. Recent data showed that growth factors mediate neuroprotection in rodent models of Parkinson's disease, modulating pro-inflammatory processes. Based on our recent studies showing that plasma rich in growth factors (PRGF-Endoret) mediates neuroprotection as inflammatory moderator in Alzheimer's disease, in the present study we examined the effects of plasma rich in growth factors (PRGF-Endoret) in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse as a translational therapeutic approach for Parkinson's disease. We found substantial neuroprotection by PRGF-Endoret in our model of Parkinson's disease, which resulted in diminished inflammatory responses and improved motor performance. Additionally, these effects were associated with robust reduction in nuclear transcription factor-κB (NF-κB) activation, and nitric oxide (NO), cyclooxygenase-2 (COX-2), and tumor necrosis factor-alpha (TNF-α) expression in the substantia nigra. We propose that PRGF-Endoret can prevent dopaminergic degeneration via an NF-κB-dependent signaling process. As the clinical safety profile of PRGF-Endoret is already established, these data suggest that PRGF-Endoret provides a novel neuroprotective strategy for Parkinson's disease.

Lignans from the stems of Clematis armandii ("Chuan-Mu-Tong") and their anti-neuroinflammatory activities

ETHNOPHARMACOLOGICAL RELEVANCE

The dried stems of Clematis armandii (Caulis clematidis armandii), named "Chuan-Mu-Tong" in Chinese Pharmacopoeia, have been traditionally used as an herbal remedy mainly for inflammation-associated diseases. The Aim of the study is to identify the potential anti-neuroinflammatory components from Clematis armandii.

MATERIALS AND METHODS

The ethanol extract of "Chuan-Mu-Tong" was suspended in H₂O and exhaustively extracted with CH₂Cl₂. The CH₂Cl₂ fraction was successively subjected to column chromatography (CC) over silica gel, Sephadex LH-20, and semi-preparative HPLC. The structures of the isolated compounds were identified by spectroscopic methods and by comparison with those reported in the literature. Their anti-neuroinflammatory activities were evaluated by inhibitory effects on pro-inflammatory mediators [e.g. nitric oxide (NO) and tumor necrosis factor-alpha (TNF-α)] in lipopolysaccharide (LPS)-activated BV-2 cells.

RESULTS

One new and sixteen known lignans were isolated and characterized. The absolute configuration of the new lignan, (7R,8S)-9-acetyl-dehydrodiconiferyl alcohol (1), was elucidated by a combination of 1D/2D NMR techniques and the Electronic Circular Dichroism (ECD) spectroscopy based on the empirical helicity rules. The anti-neuroinflammatory bioassay showed that compounds 1, (7R,8S)-dehydrodiconiferyl alcohol (2), erythro-guaiacylglycerol-β-coniferyl ether (5), and threo-guaiacylglycerol-β-coniferyl ether (6) displayed significant inhibitory effects on NO production. Among them, neolignans 1 and 2 exhibited more potent activities than the positive control (N(G)-monomethyl-L-arginine, L-NMMA), with an IC₅₀ value of 9.3 and 3.9 μM, respectively. Moreover, both 1 and 2 were also found to concentration-dependently suppress the TNF-α release in LPS-stimulated BV-2 cells.

CONCLUSION

The results revealed that lignans are the major components of "Chuan-Mu-Tong", and their anti-neuroinflammatory activities strongly support the traditional application of this herb medicine on inflammation. Moreover, the dihydrobenzo[b]furan neolignans 1 and 2 as well as Caulis clematidis armandii could be further exploited as new therapeutic agents to treat inflammation-mediated neurodegenerative and aging-associated diseases.

Neuroprotective benzyl benzoate glycosides from Disporum viridescens roots in HT22 hippocampal neuronal cells

Bioassay-guided fractionation of the EtOAc extract from Disporum viridescens roots led to the isolation of five new benzyl benzoate glycosides, BBGs (1-5). The neuroprotective activities of the BBGs were screened using neuronal HT22 hippocampal cells. BBG-D (4) significantly protected murine hippocampal HT22 cells against glutamate-induced neurotoxicity by maintaining the antioxidative defense systems such as superoxide dismutase, glutathione reductase, glutathione peroxidase, and the glutathione content. BBG-D, in a dose-and time-dependent manner, increased HO-1 expression through the selective activation of pERK signaling among the MAPK pathways. These results suggest that BBG-D could be a promising candidate for the treatment of neurodegenerative diseases related to glutamate-induced oxidative neuronal cytotoxicity.

Macelignan attenuated allergic lung inflammation and airway hyper-responsiveness in murine experimental asthma

AIMS

Macelignan isolated from Myristica fragrans Houtt. is widely used for spice and flavoring for foods, and has been reported to have anti-inflammatory activity. The aim of this study was to investigate the effects of macelignan on allergic lung inflammation with a murine model of experimental asthma.

MAIN METHODS

Fungal protease mixed with chicken egg ovalbumin allergen was used as a challenge to induce murine experimental asthma. To determine its effects on allergy and inflammation, macelignan was administered orally during allergen challenge, and the symptoms of allergic asthma and its underlined mechanisms were examined.

KEY FINDINGS

Treatment with macelignan attenuated eosinophilic airway inflammation and airway hyper-responsiveness. With the administration of macelignan, interleukin-4 (IL-4) producing cells, but not interferon-γ (IFN-γ) or IL-17 producing cells, were diminished in the lungs. Additionally, activation of the T helper type 2 (Th2) cell-specific master transcription factor, GATA3 was decreased with macelignan treatment. Finally, production of IL-4 but not IFN-γ or IL-17, by CD4(+) T cells was reduced with stimulation when combined with the administration of macelignan.

SIGNIFICANCE

Our data show that macelignan has anti-inflammatory effects on Th2 cell-mediated allergic lung inflammation and could potentially provide a novel preventative and/or therapy for the treatment of allergic diseases.

Multiple biological properties of macelignan and its pharmacological implications

Macelignan found in the nutmeg mace of Myristica fragrans obtains increasing attention as a new avenue in treating various diseases. Macelignan has been shown to possess a spectrum of pharmacological activities, including anti-bacterial, anti-inflammatory, anti-cancer, anti-diabetes, and hepatoprotective activities; recently, it has also been shown to have neuroprotective activities. This review summarizes the current research on the biological effects of macelignan derived from M. fragrans, with emphasis on the importance in understanding and treating complex diseases such as cancer and Alzheimer's disease.

Protection of MPTP-induced neuroinflammation and neurodegeneration by Pycnogenol

Oxidative stress and inflammation play a crucial role in Parkinson's disease (PD) pathogenesis and may represent a target for treatment. Current PD drugs provide only symptomatic relief and have limitations in terms of adverse effects and inability to prevent neurodegeneration. Flavonoids have been suggested to exert human health benefits by its anti-oxidant and anti-inflammatory properties. Therefore, in the present study, using 1-methyl-4-phenyl-1,2,3,6-tetrahydro pyridine (MPTP)-induced mouse model of Parkinsonism, we investigated the neuroprotective potential of bioflavonoid compound Pycnogenol® (PYC), an extract of Pinus maritime bark. MPTP injected mice developed significantly severe oxidative stress and impaired motor coordination at day 1 and day 7 postinjection. This was associated with significantly increased inflammatory responses of astrocyte and microglia as assessed by ionized calcium binding adaptor molecule 1 (Iba 1) and glial fibrillary acidic protein (GFAP) immunohistochemistry, and nuclear transcription factor-κB (NF-κB), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in the striata by Western blot. Additionally, there was significant upregulation of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) expression in the striata of MPTP injected mice compared to saline controls. The MPTP-induced neuroinflammation, neurodegeneration and behavioral impairments were markedly repudiated by treatment with PYC. These results suggest that PYC protects dopaminergic neurons from MPTP-induced toxicity in the mouse model of PD. Thus, the present finding of PYC-induced adaptation to oxidative stress and inflammation could suggest a novel avenue for clinical intervention in neurodegenerative diseases including PD.

Curcumin abates hypoxia-induced oxidative stress based-ER stress-mediated cell death in mouse hippocampal cells (HT22) by controlling Prdx6 and NF-κB regulation

Oxidative stress and endoplasmic reticulum (ER) stress are emerging as crucial events in the etiopathology of many neurodegenerative diseases. While the neuroprotective contributions of the dietary compound curcumin has been recognized, the molecular mechanisms underlying curcumin's neuroprotection under oxidative and ER stresses remains elusive. Herein, we show that curcumin protects HT22 from oxidative and ER stresses evoked by the hypoxia (1% O(2) or CoCl(2) treatment) by enhancing peroxiredoxin 6 (Prdx6) expression. Cells exposed to CoCl(2) displayed reduced expression of Prdx6 with higher reactive oxygen species (ROS) expression and activation of NF-κB with IκB phosphorylation. When NF-κB activity was blocked by using SN50, an inhibitor of NF-κB, or cells treated with curcumin, the repression of Prdx6 expression was restored, suggesting the involvement of NF-κB in modulating Prdx6 expression. These cells were enriched with an accumulation of ER stress proteins, C/EBP homologous protein (CHOP), GRP/78, and calreticulin, and had activated states of caspases 12, 9, and 3. Reinforced expression of Prdx6 in HT22 cells by curcumin reestablished survival signaling by reducing propagation of ROS and blunting ER stress signaling. Intriguingly, knockdown of Prdx6 by antisense revealed that loss of Prdx6 contributed to cell death by sustaining enhanced levels of ER stress-responsive proapoptotic proteins, which was due to elevated ROS production, suggesting that Prdx6 deficiency is a cause of initiation of ROS-mediated ER stress-induced apoptosis. We propose that using curcumin to reinforce the naturally occurring Prdx6 expression and attenuate ROS-based ER stress and NF-κB-mediated aberrant signaling improves cell survival and may provide an avenue to treat and/or postpone diseases associated with ROS or ER stress.

Anti-platelet activity of erythro-(7S,8R)-7-acetoxy-3,4,3',5'-tetramethoxy-8-O-4'-neolignan from Myristica fragrans

Platelets play a critical role in pathogenesis of cardiovascular disorders and strokes. The inhibition of platelet function is beneficial for the treatment and prevention of these diseases. In this study, we investigated the anti-platelet activity of erythro-(7S,8R)-7-acetoxy-3,4,3',5'-tetramethoxy-8-O-4'-neolignan (EATN), a neolignan isolated from Myristica fragrans, using human platelets. EATN preferentially inhibited thrombin- and platelet-activating factor (PAF)-induced platelet aggregation without affecting platelet damage in a concentration-dependent manner with IC50 values of 3.2 ± 0.4 and 3.4 ± 0.3 μM, respectively. However, much higher concentrations of EATN were required to inhibit platelet aggregation induced by arachidonic acid. EATN also inhibited thrombin-induced serotonin and ATP release, and thromboxane B2 formation in human platelets. Moreover, EATN caused an increase in cyclic AMP (cAMP) levels and attenuated intracellular Ca(2+) mobilization in thrombin-activated human platelets. Therefore, we conclude that the inhibitory mechanism of EATN on platelet aggregation may increase cAMP levels and subsequently inhibit intracellular Ca(2+) mobilization by interfering with a common signaling pathway rather than by directly inhibiting the binding of thrombin or PAF to their receptors. This is the first report of the anti-platelet activity of EATN isolated from M. fragrans.

Catalpol inhibits LPS plus IFN-γ-induced inflammatory response in astrocytes primary cultures

A large body of evidence suggests that the inflammatory reaction plays an important role in the pathogenesis of neurodegenerative diseases. Our previous studies described the neuroprotective effects of catalpol in lipopolysaccharide (LPS)-induced inflammatory models, in which catalpol was shown to prevent mesencephalic neuron death and ameliorate cognitive ability animals. To further investigate the protective effect and underlying mechanism of catalpol, astrocytes were pretreated with low (0.1mM) and high dose (0.5mM) catalpol for 1h prior to LPS plus interferon-γ stimulation. Biochemical analyses showed that NO and ROS production and iNOS activity were significantly reduced by catalpol. Data at transcriptional level also demonstrated that catalpol potently attenuated gene expressions involved in inflammation, such as iNOS, COX-2 and TLR4. In addition, our exploration further revealed that the suppressive action of catalpol on inflammation was mediated via inhibiting nuclear factor-κB (NF-κB) activation. Collectively, these results suggest that catalpol can exert inhibitory effects on the inflammatory reaction in astrocytes and that inactivation of NF-κB could be the major determinant for its anti-inflammatory mechanism. Therefore, catalpol may potentially be a highly effective therapeutic agent in treating neurodegenerative diseases associated with inflammation.

Rhinacanthus nasutus extracts prevent glutamate and amyloid-β neurotoxicity in HT-22 mouse hippocampal cells: possible active compounds include lupeol, stigmasterol and β-sitosterol

The Herb Rhinacanthus nasutus (L.) Kurz, which is native to Thailand and Southeast Asia, has become known for its antioxidant properties. Neuronal loss in a number of diseases including Alzheimer’s disease is thought to result, in part, from oxidative stress. Glutamate causes cell death in the mouse hippocampal cell line, HT-22, by unbalancing redox homeostasis, brought about by a reduction in glutathione levels, and amyloid-β has been shown to induce reactive oxygen species (ROS) production. Here in, we show that ethanol extracts of R. nasutus leaf and root are capable of dose dependently attenuating the neuron cell death caused by both glutamate and amyloid-β treatment. We used free radical scavenging assays to measure the extracts antioxidant activities and as well as quantifying phenolic, flavonoid and sterol content. Molecules found in R. nasutus, lupeol, stigmasterol and β-sitosterol are protective against glutamate toxicity.

Involvement of Heme Oxygenase-1 Induction in the Cytoprotective and Immunomodulatory Activities of Viola patrinii in Murine Hippocampal and Microglia Cells

A number of diseases that lead to injury of the central nervous system are caused by oxidative stress and inflammation in the brain. In this study, NNMBS275, consisting of the ethanol extract of Viola patrinii, showed potent antioxidative and anti-inflammatory activity in murine hippocampal HT22 cells and BV2 microglia. NNMBS275 increased cellular resistance to oxidative injury caused by glutamate-induced neurotoxicity and reactive oxygen species generation in HT22 cells. In addition, the anti-inflammatory effects of NNMBS275 were demonstrated by the suppression of proinflammatory mediators, including proinflammatory enzymes (inducible nitric oxide synthase and cyclooxygenase-2) and cytokines (tumor necrosis factor-α and interleukin-1β). Furthermore, we found that the neuroprotective and anti-inflammatory effects of NNMBS275 were linked to the upregulation of nuclear transcription factor-E2-related factor 2-dependent expression of heme oxygenase-1 in HT22 and BV2 cells. These results suggest that NNMBS275 possesses therapeutic potential against neurodegenerative diseases that are induced by oxidative stress and neuroinflammation.

Myrislignan attenuates lipopolysaccharide-induced inflammation reaction in murine macrophage cells through inhibition of NF-κB signalling pathway activation

Myrislignan is a new kind of lignan isolated from Myristica fragrans Houtt. Its antiinflammatory effects have not yet been reported. In the present study, the antiinflammatory effects and the underlying mechanisms of myrislignan in lipopolysaccharide (LPS)-induced inflammation in murine RAW 264.7 macrophage cells were investigated. Myrislignan significantly inhibited LPS-induced production of nitric oxide (NO) in a dose-dependent manner. It inhibited mRNA expression and release of interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α). This compound significantly inhibited mRNA and protein expressions of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) dose-dependently in LPS-stimulated macrophage cells. Further study showed that myrislignan decreased the cytoplasmic loss of inhibitor κB-α (IκB-α) protein and the translocation of NF-κB from cytoplasm to the nucleus. Our results suggest that myrislignan may exert its antiinflammatory effects in LPS-stimulated macrophages cells by inhibiting the NF-κB signalling pathway activation.