Comparative Transcriptomic Analysis of Genes in the 20-Hydroxyecdysone Biosynthesis in the Fern Microsorum scolopendria towards Challenges with Foliar Application of Chitosan.

Microsorum scolopendria is an important medicinal plant that belongs to the Polypodiaceae family. In this study, we analyzed the effects of foliar spraying of chitosan on growth promotion and 20-hydroxyecdysone (20E) production in M. scolopendria. Treatment with chitosan at a concentration of 50 mg/L in both young and mature sterile fronds induced the highest increase in the amount of accumulated 20E. Using RNA sequencing, we identified 3552 differentially expressed genes (DEGs) in response to chitosan treatment. The identified DEGs were associated with 236 metabolic pathways. We identified several DEGs involved in the terpenoid and steroid biosynthetic pathways that might be associated with secondary metabolite 20E biosynthesis. Eight upregulated genes involved in cholesterol and phytosterol biosynthetic pathway, five upregulated genes related to the methylerythritol 4-phosphate (MEP) and mevalonate (MVA) pathways, and several DEGs that are members of cytochrome P450s and ABC transporters were identified. Quantitative real-time RT-PCR confirmed the results of RNA-sequencing. Taken together, we showed that chitosan treatment increased plant dry weight and 20E accumulation in M. scolopendria. RNA-sequencing and DEG analyses revealed key enzymes that might be related to the production of the secondary metabolite 20E in M. scolopendria.

Butein-Enriched Fractions of Butea monosperma (Lam.) Taub. Flower Decrease Weight Gains and Increase Energy Expenditure in High-Fat Diet-Induced Obese Mice.

Butea monosperma (Lam.) Taub. has been applied to treat inflammatory, metabolic, and infectious diseases. However, the antiobesity effects of B. monosperma (Lam.) Taub. flower (BMF) and the underlying mechanisms have not been determined. In this study, we analyzed the various extraction procedures, investigated the antiobesity effects, and identified the main chemical constituents of BMF. The BMF was subjected to acid hydrolysis in 5% H2SO4 in methanol at 50°C for 48 h and partitioned with ethyl acetate. The acid-hydrolyzed BMF ethyl acetate extracts (BMFE) strongly induced the expression of uncoupling protein 1 (Ucp1) and other thermogenic genes in C3H10T1/2 adipocytes. Daily oral administration of 70 mg/kg BMFE (BMFE70) to mice with diet-induced obesity resulted in less body weight gain, increased glucose tolerance, higher rectal temperature, and increased oxygen consumption. Qualitative and quantitative analyses along with treatments in Akt1 knockout mouse embryonic fibroblasts indicate that butein is a major active ingredient of BMFE, which stimulates Ucp1 gene expression. These data show the effects of butein-containing B. monosperma flower extract on thermogenesis and energy expenditure, further suggesting the potential role of BMFE as a functional ingredient in obesity and related metabolic diseases.

Identification of a Novel Geminivirus in Fraxinus rhynchophylla in Korea.

Fraxinus rhynchophylla, common name ash, belongs to the family Oleaceae and is found in China, Korea, North America, the Indian subcontinent, and eastern Russia. It has been used as a traditional herbal medicine in Korea and various parts of the world due to its chemical constituents. During a field survey in March 2019, mild vein thickening (almost negligible) was observed in a few ash trees. High-throughput sequencing of libraries of total DNA from ash trees, rolling-circle amplification (RCA), and polymerase chain reaction (PCR) allowed the identification of a Fraxinus symptomless virus. This virus has five confirmed open reading frames along with a possible sixth open reading frame that encodes the movement protein and is almost 2.7 kb in size, with a nonanucleotide and stem loop structure identical to begomoviruses. In terms of its size and structure, this virus strongly resembles begomoviruses, but does not show any significant sequence identity with them. To confirm movement of the virus within the trees, different parts of infected trees were examined, and viral movement was successfully observed. No satellite molecules or DNA B were identified. Two-step PCR confirmed the virion and complementary strands during replication in both freshly collected infected samples of ash tree and Nicotiana benthamiana samples agro-inoculated with infectious clones. This taxon is so distantly grouped from other known geminiviruses that it likely represents a new geminivirus genus.

De Novo Transcriptome Assembly of Two Microsorum Fern Species Identifies Enzymes Required for Two Upstream Pathways of Phytoecdysteroids.

Microsorum species produce a high amount of phytoecdysteroids (PEs), which are widely used in traditional medicine in the Pacific islands. The PEs in two different Microsorum species, M. punctatum (MP) and M. scolopendria (MS), were examined using high-performance liquid chromatography (HPLC). In particular, MS produces a high amount of 20-hydroxyecdysone, which is the main active compound in PEs. To identify genes for PE biosynthesis, we generated reference transcriptomes from sterile frond tissues using the NovaSeq 6000 system. De novo transcriptome assembly after deleting contaminants resulted in 57,252 and 54,618 clean transcripts for MP and MS, respectively. The clean Microsorum transcripts for each species were annotated according to gene ontology terms, UniProt pathways, and the clusters of the orthologous group protein database using the MEGAN6 and Sma3s programs. In total, 1852 and 1980 transcription factors were identified for MP and MS, respectively. We obtained transcripts encoding for 38 and 32 enzymes for MP and MS, respectively, potentially involved in mevalonate and sterol biosynthetic pathways, which produce precursors for PE biosynthesis. Phylogenetic analyses revealed many redundant and unique enzymes between the two species. Overall, this study provides two Microsorum reference transcriptomes that might be useful for further studies regarding PE biosynthesis in Microsorum species.

Administration of L. salivarius expressing 3D8 scFv as a feed additive improved the growth performance, immune homeostasis, and gut microbiota of chickens.

Probiotics have been defined as live microorganisms that are administered in an appropriate amount to provide health benefits to the host animal. In this study, we investigated the effect of L. salivarius DJ-sa-01 secreting the 3D8 single-chain variable fragment (3D8 scFv) on the growth performance, cytokine secretion, and intestinal microbial flora of chickens. The experiment was divided into the control group and L. salivarius expressing 3D8 scFv experimental group. Chicken was fed 109 colony-forming units (CFUs) of wild-type (WT) L. salivarius or 3D8 scFv-secreting L. salivarius daily for 35 days. The administration of L. salivarius expressing 3D8 scFv significantly improved the body weight of chickens compared with the administration of WT L. salivarius. A 16S ribosomal RNA metagenomic analysis showed that Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were the dominant phyla in both experimental groups. At the genus level, Lactobacillus was more abundant (22.82%) in the L. salivarius/3D8 group compared with the WT L. salivarius group. The serum levels of cytokines, such as IL-8, TNF-α, IL-1ß, IFN-γ, IL-4, and IGF1, were significantly reduced in the L. salivarius/3D8-treated chickens. In summary, our results suggest that L. salivarius expressing 3D8 scFv could be considered a feed additive for improving the growth performance, immune function, and disease resistance of poultry.

Enhanced Anticancer Effect of Adding Magnesium to Vitamin C Therapy: Inhibition of Hormetic Response by SVCT-2 Activation.

l-Ascorbic acid (vitamin C, AA) is known as an antioxidant, but at high concentrations, AA can kill cancer cells through a prooxidant property. Sodium-dependent vitamin C transporter family-2 (SVCT-2) determines the cellular uptake of AA, and the activity of SVCT-2 is directly related to the anticancer activity of AA. Cancer cells that showed high SVCT-2 expression levels were more sensitive to AA treatment than cancer cells with low SVCT-2 expression levels. Cells with low SVCT-2 expression showed a hormetic response to a low dose of AA. Magnesium ions, which are known to activate SVCT-2, could increase the Vmax value of SVCT-2, so we investigated whether providing magnesium supplements to cancer cells with low SVCT-2 expression that had shown a hormetic response to AA would elevate the Vmax value of SVCT-2, allowing more AA to accumulate. To evaluate the effects of magnesium on cancer cells, MgSO4 and MgCl2 were screened as magnesium supplements; both forms showed synergistic anticancer effects with AA. Taken together, the results of this study suggest that magnesium supplementation enhanced the anticancer effect of AA by inhibiting the hormetic response at a low dose. This study has also demonstrated that AA treatment with magnesium supplementation provided more effective anticancer therapy than AA treatment alone.

Neural circuits underlying a psychotherapeutic regimen for fear disorders.

A psychotherapeutic regimen that uses alternating bilateral sensory stimulation (ABS) has been used to treat post-traumatic stress disorder. However, the neural basis that underlies the long-lasting effect of this treatment-described as eye movement desensitization and reprocessing-has not been identified. Here we describe a neuronal pathway driven by the superior colliculus (SC) that mediates persistent attenuation of fear. We successfully induced a lasting reduction in fear in mice by pairing visual ABS with conditioned stimuli during fear extinction. Among the types of visual stimulation tested, ABS provided the strongest fear-reducing effect and yielded sustained increases in the activities of the SC and mediodorsal thalamus (MD). Optogenetic manipulation revealed that the SC-MD circuit was necessary and sufficient to prevent the return of fear. ABS suppressed the activity of fear-encoding cells and stabilized inhibitory neurotransmission in the basolateral amygdala through a feedforward inhibitory circuit from the MD. Together, these results reveal the neural circuit that underlies an effective strategy for sustainably attenuating traumatic memories.

Hormetic dose response to L-ascorbic acid as an anti-cancer drug in colorectal cancer cell lines according to SVCT-2 expression.

L-Ascorbic acid (vitamin C, AA) exhibits anti-cancer effects with high-dose treatment through the generation of reactive oxygen species (ROS) and selective damage to cancer cells. The anti-cancer effects of L-ascorbic acid are determined by sodium-dependent vitamin C transporter 2 (SVCT-2), a transporter of L-ascorbic acid. In this study, we demonstrate that L-ascorbic acid treatment showed efficient anti-cancer activity in cell lines with high expression levels of SVCT-2 for a gradient concentration of L-ascorbic acid from 10 µM -2 mM. However, in low SVCT-2 expressing cell lines, high-dose L-ascorbic acid (>1 mM) showed anti-cancer effects but low-dose (<10 µM) treatment induced cell proliferation. Such conflicting results that depend on the concentration are called a hormetic dose response. A hormetic dose response to low-dose L-ascorbic acid was also observed in high SVCT-2 expressing cell lines in the presence of a SVCT family inhibitor. Insufficient uptake of L-ascorbic acid in low SVCT-2 expressing cancer cell lines cannot generate sufficient ROS to kill cancer cells, resulting in the hormetic response. Molecular analysis confirmed the increased expression of cancer proliferation markers in the hormetic dose response. These results suggest that L-ascorbic exhibits a biphasic effect in cancer cells depending on SVCT-2 expression.

Sulfuretin has therapeutic activity against acquired lymphedema by reducing adipogenesis.

Acquired lymphedema is a pathological condition associated with lymphatic dysfunction caused by surgical treatments for cancer. Although global estimates of the prevalence of acquired lymphedema have been rising, there are currently no effective therapeutics available. Since adipose tissue accumulation is a clinical hallmark of lymphedema, we hypothesized that regulation of adipogenesis in lymphedematous tissue could be used as a therapeutic intervention against lymphedema. Toward this, we investigated the possibility of anti-adipogenic 30% ethanol Rhus verniciflua Stokes (RVS) extract as a potential lymphedema treatment. Oral administration of RVS extract ameliorated volumetric symptoms of lymphedema in a mouse model. RVS administration also reduced adipose tissue accumulation in lymphedematous tissue and downregulated expression of adipocyte markers, including Pparγ and Fabp4. Sulfuretin was identified as a major bioactive compound in the 30% ethanol RVS extract in liquid chromatography-mass spectrometry analysis. Similar to the activities of RVS, sulfuretin inhibited adipocyte differentiation in 3T3-L1 preadipocytes. Moreover, treatment with sulfuretin on lymphedema-induced mice reduced lymphedema volume, decreased the expression of adipogenic markers, but induced the expression of markers associated with lymphangiogenesis. Taken together, our data raise the possibility that sulfuretin might be used in therapeutic interventions against acquired lymphedema.

Therapeutic Strategy for the Prevention of Pseudorabies Virus Infection in C57BL/6 Mice by 3D8 scFv with Intrinsic Nuclease Activity.

3D8 single chain variable fragment (scFv) is a recombinant monoclonal antibody with nuclease activity that was originally isolated from autoimmune-prone MRL mice. In a previous study, we analyzed the nuclease activity of 3D8 scFv and determined that a HeLa cell line expressing 3D8 scFv conferred resistance to herpes simplex virus type 1 (HSV-1) and pseudorabies virus (PRV). In this study, we demonstrate that 3D8 scFv could be delivered to target tissues and cells where it exerted a therapeutic effect against PRV. PRV was inoculated via intramuscular injection, and 3D8 scFv was injected intraperitoneally. The observed therapeutic effect of 3D8 scFv against PRV was also supported by results from quantitative reverse transcription polymerase chain reaction, southern hybridization, and immunohistochemical assays. Intraperitoneal injection of 5 and 10 µg 3D8 scFv resulted in no detectable toxicity. The survival rate in C57BL/6 mice was 9% after intramuscular injection of 10 LD50 PRV. In contrast, the 3D8 scFv-injected C57BL/6 mice showed survival rates of 57% (5 µg) and 47% (10 µg). The results indicate that 3D8 scFv could be utilized as an effective antiviral agent in several animal models.

In vitro and in vivo anti-inflammatory activity of Phyllanthus acidus methanolic extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Phyllanthus acidus (L.) Skeels (Phyllanthaceae) has traditionally been used to treat gastric trouble, rheumatism, bronchitis, asthma, respiratory disorders, and hepatitis. Despite this widespread use, the pharmacological activities of this plant and their molecular mechanisms are poorly understood. Therefore, we evaluated the immunopharmacological activities of the methanolic extract of the aerial parts of this plant (Pa-ME) and validated its pharmacological targets. MATERIALS AND METHODS: Lipopolysaccharide (LPS)-treated macrophages, an HCl/EtOH-induced gastritis model, and an acetic acid-injected capillary permeability mouse model were employed to evaluate the anti-inflammatory activity of Pa-ME. Potentially active anti-inflammatory components of this extract were identified by HPLC. The molecular mechanisms of the anti-inflammatory activity were studied by kinase assays, reporter gene assays, immunoprecipitation analysis, and overexpression of target enzymes. RESULTS: Pa-ME suppressed the production of nitric oxide (NO) and prostaglandin E2 (PGE2) and prevented morphological changes in LPS-treated RAW264.7 cells. Moreover, both HCl/EtOH-induced gastric damage and acetic acid-triggered vascular permeability were restored by orally administered Pa-ME. Furthermore, this extract downregulated the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 and reduced the nuclear levels of NF-κB. Signalling events upstream of NF-κB translocation, such as phosphorylation of Src and Syk and formation of Src/Syk signalling complexes, were also inhibited by Pa-ME. The enzymatic activities of Src and Syk were also suppressed by Pa-ME. Moreover, Src-induced and Syk-induced luciferase activity and p85/Akt phosphorylation were also inhibited by Pa-ME. Of the identified flavonoids, kaempferol and quercetin were revealed as partially active anti-inflammatory components in Pa-ME. CONCLUSION: Pa-ME exerts anti-inflammatory activity in vitro and in vivo by suppressing Src, Syk, and their downstream transcription factor, NF-κB.

Ascorbic acid and a cytostatic inhibitor of glycolysis synergistically induce apoptosis in non-small cell lung cancer cells.

Ascorbic acid (AA) exhibits significant anticancer activity at pharmacologic doses achievable by parenteral administration that have minimal effects on normal cells. Thus, AA has potential uses as a chemotherapeutic agent alone or in combination with other therapeutics that specifically target cancer-cell metabolism. We compared the effects of AA and combinations of AA with the glycolysis inhibitor 3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one (3-PO) on the viability of three non-small cell lung cancer (NSCLC) cell lines to the effects on an immortalized lung epithelial cell line. AA concentrations of 0.5 to 5 mM caused a complete loss of viability in all NSCLC lines compared to a <10% loss of viability in the lung epithelial cell line. Combinations of AA and 3-PO synergistically enhanced cell death in all NSCLC cell lines at concentrations well below the IC50 concentrations for each compound alone. A synergistic interaction was not observed in combination treatments of lung epithelial cells and combination treatments that caused a complete loss of viability in NSCLC cells had modest effects on normal lung cell viability and reactive oxygen species (ROS) levels. Combination treatments induced dramatically higher ROS levels compared to treatment with AA and 3-PO alone in NSCLC cells and combination-induced cell death was inhibited by addition of catalase to the medium. Analyses of DNA fragmentation, poly (ADP-ribose) polymerase cleavage, annexin V-binding, and caspase activity demonstrated that AA-induced cell death is caused via the activation of apoptosis and that the combination treatments caused a synergistic induction of apoptosis. These results demonstrate the effectiveness of AA against NSCLC cells and that combinations of AA with 3-PO synergistically induce apoptosis via a ROS-dependent mechanism. These results support further evaluation of pharmacologic concentrations of AA as an adjuvant treatment for NSCLC and that combination of AA with glycolysis inhibitors may be a promising therapy for the treatment of NSCLC.

Altered invertase activities of symptomatic tissues on Beet severe curly top virus (BSCTV) infected Arabidopsis thaliana.

Arabidopsis thaliana infected with Beet severe curly top virus (BSCTV) exhibits systemic symptoms such as stunting of plant growth, callus induction on shoot tips, and curling of leaves and shoot tips. The regulation of sucrose metabolism is essential for obtaining the energy required for viral replication and the development of symptoms in BSCTV-infected A. thaliana. We evaluated the changed transcript level and enzyme activity of invertases in the inflorescence stems of BSCTV-infected A. thaliana. These results were consistent with the increased pattern of ribulose-1,5-bisphosphate carboxylase/oxygenase activity and photosynthetic pigment concentration in virus-infected plants to supply more energy for BSCTV multiplication. The altered gene expression of invertases during symptom development was functionally correlated with the differential expression patterns of D-type cyclins, E2F isoforms, and invertase-related genes. Taken together, our results indicate that sucrose sensing by BSCTV infection may regulate the expression of sucrose metabolism and result in the subsequent development of viral symptoms in relation with activation of cell cycle regulation.

In vitro and in vivo anti-inflammatory effect of Rhodomyrtus tomentosa methanol extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhodomyrtus tomentosa (Aiton) Hassk. is a representative Thai medicinal plant traditionally used in South Asian countries to relieve various inflammatory symptoms. However, no systematic studies on its anti-inflammatory activity and mechanisms have been reported. MATERIALS AND METHODS: The effect of the methanol extract from the leaves of this plant (Rt-ME) on the production of inflammatory mediators [nitric oxide (NO) and prostaglandin E2 (PGE2)] and the molecular mechanism of Rt-ME-mediated inhibition, including target enzymes, were studied with RAW264.7, peritoneal macrophage, and HEK293 cells. Additionally, the in vivo anti-inflammatory activity of this extract was evaluated with mouse gastritis and colitis models. RESULTS: Rt-ME clearly inhibited the production of NO and PGE2 in lipopolysaccharide (LPS)-activated RAW264.7 cells and peritoneal macrophages in a dose-dependent manner. According to RT-PCR, immunoblotting and immunoprecipitation analyses and a kinase assay with mRNA, whole cell extract, and nucleus lysates from RAW264.7 cells and mice, it was revealed that Rt-ME was capable of suppressing the activation of both nuclear factor (NF)-κB and activator protein (AP)-1 pathways by directly targeting Syk/Src and IRAK1/IRAK4. CONCLUSION: Rt-ME could have anti-inflammatory properties by suppressing Syk/Src/NF-kB and IRAK1/IRAK4/AP-1 pathways and will be further developed as a herbal remedy for preventive and/or curative purposes in various inflammatory diseases.

Methanol extract of Hopea odorata suppresses inflammatory responses via the direct inhibition of multiple kinases.

ETHNOPHARMACOLOGICAL RELEVANCE: Hopea odorata Roxb. (Dipterocarpaceae) is a representative Thai ethnopharmacological herbal plant used in the treatment of various inflammation-related diseases. In spite of its traditional use, systematic studies of its anti-inflammatory action have not been performed. MATERIALS AND METHODS: The inhibitory activities of a Hopea odorata methanol extract (Ho-ME) on the production of nitric oxide (NO), tumour necrosis factor (TNF)-α, and prostaglandin E(2) (PGE(2)) in RAW264.7 cells and peritoneal macrophages were investigated. The effects of Ho-ME on the gastritis symptoms induced by HCl/EtOH and on ear oedemas induced by arachidonic acid were also examined. Furthermore, to identify the immunopharmacological targets of this extract, nuclear fractionation, a reporter gene assay, immunoprecipitation, immunoblot analysis, and a kinase assay were employed. RESULTS: Ho-ME strongly inhibited the release of NO, PGE(2), and TNF-α in RAW264.7 cells and peritoneal macrophages stimulated by lipopolysaccharide (LPS). Ho-ME also clearly suppressed the gene expression of pro-inflammatory cytokines and chemokines, such as interferon (IFN)-ß, interleukin (IL)-12, and monocyte chemotactic protein-1 (MCP-1). By analysing the inhibited target molecules, Syk and Src were found to be suppressed in the inhibition of nuclear factor (NF)-κB pathway. In addition, the observed downregulation of activator protein (AP)-1 and cAMP response element-binding (CREB) was due to the direct inhibition of interleukin-1 receptor-associated kinase (IRAK)1 and IRAK4, which was also linked to the suppression of c-Jun N-terminal kinase (JNK) and p38. In agreement with the in vitro observations, this extract also ameliorated the inflammatory symptoms in EtOH/HCl-induced gastritis and arachidonic acid-induced ear oedemas in mice. CONCLUSION: Ho-ME has potential as a functional herbal remedy targeting Syk- and Src-mediated anti-inflammatory mechanisms. Future pre-clinical studies will be needed to investigate this possibility.

Lateralization of observational fear learning at the cortical but not thalamic level in mice.

Major cognitive and emotional faculties are dominantly lateralized in the human cerebral cortex. The mechanism of this lateralization has remained elusive owing to the inaccessibility of human brains to many experimental manipulations. In this study we demonstrate the hemispheric lateralization of observational fear learning in mice. Using unilateral inactivation as well as electrical stimulation of the anterior cingulate cortex (ACC), we show that observational fear learning is controlled by the right but not the left ACC. In contrast to the cortex, inactivation of either left or right thalamic nuclei, both of which are in reciprocal connection to ACC, induced similar impairment of this behavior. The data suggest that lateralization of negative emotions is an evolutionarily conserved trait and mainly involves cortical operations. Lateralization of the observational fear learning behavior in a rodent model will allow detailed analysis of cortical asymmetry in cognitive functions.

Methanol extract of Osbeckia stellata suppresses lipopolysaccharide- and HCl/ethanol-induced inflammatory responses by inhibiting Src/Syk and IRAK1.

ETHNOPHARMACOLOGICAL RELEVANCE: Osbeckia stellata Buch.-Ham. ex D.Don is traditionally prescribed to treat various inflammatory diseases. However, how this plant is able to modulate inflammatory responses is unknown. This study explored the anti-inflammatory effects of 99% methanol extracts of O. stellata (Os-ME). MATERIALS AND METHODS: The anti-inflammatory effect of Os-ME was evaluated by measuring the levels of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) in lipopolysaccharide (LPS)-treated RAW264.7 macrophage cells and by determining gastric inflammatory lesions in mice induced by HCl/ethanol (EtOH). The molecular mechanisms of the inhibitions were elucidated by analyzing the activation of transcription factors, upstream signaling cascade, and the kinase activities of target enzymes. RESULTS: Os-ME dose-dependently diminished the release of NO and PGE(2), and suppressed the expression of inducible NO synthase and cyclooxygenase-2 in LPS-treated RAW264.7 cells. Os-ME clearly inhibited the translocation of c-Rel, a subunit of nuclear factor κB (NF-κB), and c-Fos, a subunit of activator protein-1 (AP-1), and their regulatory upstream enzymes including Src, Syk, and IRAK1. Interestingly, orally administered Os-ME ameliorated acute inflammatory symptoms and suppressed the activation of Src, Syk, and IRAK1 induced by HCl/EtOH treatment in mouse stomach. CONCLUSION: Os-ME can be considered as an orally available anti-inflammatory herbal remedy with Src/Syk/NF-κB and IRAK1/AP-1 inhibitory properties.

Src and Syk are targeted to an anti-inflammatory ethanol extract of Aralia continentalis.

ETHNOPHARMACOLOGICAL RELEVANCE: Aralia continentalis Kitagawa (Araliaceae) is a representative ethnomedicinal herbal plant traditionally prescribed in Korea to relieve various inflammatory symptoms. However, the exact molecular mechanism of its anti-inflammatory activity has not been fully investigated. MATERIALS AND METHODS: The effect of the ethanol extract from the roots of this plant (Ac-EE) on the production of the inflammatory mediator nitric oxide (NO) was studied in RAW264.7 cells. Its effect on inflammatory symptoms (gastritis and hepatitis) in mice was also examined. In particular, the molecular inhibitory mechanism was analysed by measuring the activation of transcription factors and their upstream signalling and the kinase activity of target enzymes. RESULTS: Ac-EE dose-dependently suppressed NO production in lipopolysaccharide (LPS)-activated RAW264.7 cells. This extract also displayed curative activity against EtOH/HCl-induced gastritis and LPS-induced hepatitis in mice. Ac-EE-mediated anti-inflammatory activity was found to be at the transcriptional level, as it blocked the activation of the nuclear factor (NF)-κB pathway composed of Syk and Src, according to immunoblotting and immunoprecipitation analyses and a kinase assay with whole and nucleus lysates from RAW264.7 cells and mice. CONCLUSION: Ac-EE may be developed as a functional herbal remedy targeting Syk- and Src-mediated anti-inflammatory mechanisms. Future work using pre-clinical studies will be needed to investigate this possibility.

Src/NF-κB-targeted inhibition of LPS-induced macrophage activation and dextran sodium sulphate-induced colitis by Archidendron clypearia methanol extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Archidendron clypearia Jack. (Fabaceae) has been traditionally used to treat various inflammatory diseases such as pain in the eyes. However, the antiinflammatory mechanism of A. clypearia has not been fully elucidated. This study examined the anti-inflammatory mechanism of a 95% methanol extract (Ac-ME) of A. clypearia in vitro and in vivo. MATERIALS AND METHODS: The effect of Ac-ME on the production of inflammatory mediators in RAW264.7 cells and peritoneal macrophages and on symptoms of colitis in mouse induced by dextran sodium sulphate (DSS) was investigated. Molecular mechanisms underlying the inhibitory effects were elucidated by analyzing the activation of transcription factors and their upstream signaling as well as by evaluating the kinase activity of target enzymes in vitro and in vivo. RESULTS: Ac-ME dose-dependently suppressed the secretion of nitric oxide (NO) and prostaglandin (PG)E2 from RAW264.7 cells and peritoneal macrophages stimulated by lipopolysaccharide (LPS). Ac-ME clearly reduced mRNA expression of inducible NO synthase (iNOS), cyclooxygenase (COX)-2, and tumor necrosis factor (TNF)-α by the blockade of nuclear factor (NF)-κB activation and its upstream signaling events containing protein tyrosine kinase such as Syk and Src. In agreement with this, Ac-ME directly reduced the kinase activities of Src and Syk as well as the formation of molecular signaling complex including p85. DSS-induced colitis was also remarkably inhibited by this extract through the suppression of Src and IκBα phosphorylation. CONCLUSION: Ac-ME displays strong anti-inflammatory activity in vivo by suppressing Src/Syk-mediated NF-κB activation which is linked to its ethno-pharmacological uses as an anti-gastritis remedy. Through preclinical studies, the potential therapeutic application will be tested further.

Bidirectional modulation of fear extinction by mediodorsal thalamic firing in mice.

The mediodorsal thalamic nucleus has been implicated in the control of memory processes. However, the underlying neural mechanism remains unclear. Here we provide evidence for bidirectional modulation of fear extinction by the mediodorsal thalamic nucleus. Mice with a knockout or mediodorsal thalamic nucleus-specific knockdown of phospholipase C ß4 exhibited impaired fear extinction. Mutant mediodorsal thalamic nucleus neurons in slices showed enhanced burst firing accompanied by increased T-type Ca(2+) currents; blocking of T channels in vivo rescued the fear extinction. Tetrode recordings in freely moving mice revealed that, during extinction, the single-spike (tonic) frequency of mediodorsal thalamic nucleus neurons increased in wild-type mice, but was static in mutant mice. Furthermore, tonic-evoking microstimulations of the mediodorsal thalamic nucleus, contemporaneous with the extinction tones, rescued fear extinction in mutant mice and facilitated it in wild-type mice. In contrast, burst-evoking microstimulation suppressed extinction in wild-type mice, mimicking the mutation. These results suggest that the firing mode of the mediodorsal thalamic nucleus is critical for the modulation of fear extinction.