Systematic dissection of tumor-normal single-cell ecosystems across a thousand tumors of 30 cancer types.

The complexity of the tumor microenvironment poses significant challenges in cancer therapy. Here, to comprehensively investigate the tumor-normal ecosystems, we perform an integrative analysis of 4.9 million single-cell transcriptomes from 1070 tumor and 493 normal samples in combination with pan-cancer 137 spatial transcriptomics, 8887 TCGA, and 1261 checkpoint inhibitor-treated bulk tumors. We define a myriad of cell states constituting the tumor-normal ecosystems and also identify hallmark gene signatures across different cell types and organs. Our atlas characterizes distinctions between inflammatory fibroblasts marked by AKR1C1 or WNT5A in terms of cellular interactions and spatial co-localization patterns. Co-occurrence analysis reveals interferon-enriched community states including tertiary lymphoid structure (TLS) components, which exhibit differential rewiring between tumor, adjacent normal, and healthy normal tissues. The favorable response of interferon-enriched community states to immunotherapy is validated using immunotherapy-treated cancers (n = 1261) including our lung cancer cohort (n = 497). Deconvolution of spatial transcriptomes discriminates TLS-enriched from non-enriched cell types among immunotherapy-favorable components. Our systematic dissection of tumor-normal ecosystems provides a deeper understanding of inter- and intra-tumoral heterogeneity.

Molecular Self-Assembly and Adsorption Structure of 2,2'-Dipyrimidyl Disulfides on Au(111) Surfaces.

The effects of solution concentration and pH on the formation and surface structure of 2-pyrimidinethiolate (2PymS) self-assembled monolayers (SAMs) on Au(111) via the adsorption of 2,2'-dipyrimidyl disulfide (DPymDS) were examined using scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). STM observations revealed that the formation and structural order of 2PymS SAMs were markedly influenced by the solution concentration and pH. 2PymS SAMs formed in a 0.01 mM ethanol solution were mainly composed of a more uniform and ordered phase compared with those formed in 0.001 mM or 1 mM solutions. SAMs formed in a 0.01 mM solution at pH 2 were composed of a fully disordered phase with many irregular and bright aggregates, whereas SAMs formed at pH 7 had small ordered domains and many bright islands. As the solution pH increased from pH 7 to pH 12, the surface morphology of 2PymS SAMs remarkably changed from small ordered domains to large ordered domains, which can be described as a (4√2 × 3)R51° packing structure. XPS measurements clearly showed that the adsorption of DPymDS on Au(111) resulted in the formation of 2PymS (thiolate) SAMs via the cleavage of the disulfide (S-S) bond in DPymDS, and most N atoms in the pyrimidine rings existed in the deprotonated form. The results herein will provide a new insight into the molecular self-assembly behaviors and adsorption structures of DPymDS molecules on Au(111) depending on solution concentration and pH.

Multicomponent Covalent Organic Framework Solid Electrolyte Allowing Effective Li-Ion Dissociation and Diffusion for All-Solid-State Batteries.

Organic solid electrolytes compatible with all-solid-state Li metal batteries (LMBs) are essential to ensuring battery safety, high energy density, and long-term cycling performance. However, it remains a challenge to develop an approach to provide organic solid electrolytes with capabilities for the facile dissociation of strong Li-ion pairs and fast transport of ionic components. Herein, a diethylene glycol-modified pyridinium covalent organic framework (DEG-PMCOF) with a well-defined periodic structure is prepared as a multicomponent solid electrolyte with a cationic moiety of high polarity, an additional flexible ion-transporter, and an ordered ionic channel for all-solid-state LMBs. The DEG-containing pyridinium groups of DEG-PMCOF allow a lower dissociation energy of Li salts and a smaller energy barrier of Li-ion transport, leading to high ion conductivity (1.71 × 10-4 S cm-1) and a large Li-ion transfer number (0.61) at room temperature in the solid electrolyte. The DEG-PMCOF solid electrolyte exhibits a wide electrochemical stability window and effectively suppresses the formation of Li dendrites and dead Li in all-solid-state LMBs. Molecular dynamics and density functional theory simulations provide insights into the mechanisms for the enhanced Li-ion transport driven by the integrated diffusion process based on hopping motion, vehicle motion, and free diffusion of DEG-PMCOF. The all-solid-state LMB assembled with a DEG-PMCOF solid electrolyte displays a high specific capacity with a retention of 99% and an outstanding Coulombic efficiency of 99% at various C-rates during long-term cycling. This DEG-PMCOF approach can offer an effective route to design various solid-state Li batteries.

Preferential dissolution behaviour of the austenite phase in Fe-27Cr-xC high chromium cast iron.

Preferential dissolution behaviour of the austenite (γ) phase in Fe-27Cr-xC high chromium cast irons (HCCIs) immersed in 0.1 mol dm-3 H2SO4 + 0.05 mol dm-3 HCl was investigated. Potentiodynamic and potentiostatic polarisation revealed that the primary and eutectic γ phases dissolved preferentially at -0.35 and 0.00 VSilver Silverchloride Electrode potential in sat. KCl (SSE), respectively. The immersion of the HCCIs in the solution showed that the dissolution of the primary γ phase dominated for ca. 1 h, while the primary and eutectic γ phases dissolved after ca. 1 h. However, the carbide phases remained undissolved during the dissolution of the γ phases. Furthermore, the corrosion rate of the HCCIs increased with the increasing C content owing to the increase in the contact potential difference values of the γ and carbide phases. The change in electromotive force due to C addition was related to the accelerated corrosion rate of the γ phases.

An Ion-Channel-Restructured Zwitterionic Covalent Organic Framework Solid Electrolyte for All-Solid-State Lithium-Metal Batteries.

Organic solid electrolytes offer an effective route for safe and high-energy-density all-solid-state Li metal batteries. However, it remains a challenge to devise a new strategy to promote the dissociation of strong ion pairs and the transport of ionic components in organic solid electrolytes. Herein, a zwitterionic covalent organic framework (Zwitt-COF) with well-defined chemical and pore structures is prepared as a solid electrolyte capable of accelerating the dissociation and transport of Li ions. The Zwitt-COF solid electrolyte exhibits a high room-temperature ionic conductivity of 1.65 × 10-4  S cm-1 with a wide electrochemical stability window. Besides, the Zwitt-COF solid electrolyte displays stable Li plating/stripping behavior via effective inhibition of the formation of Li dendrites and dead Li, leading to superior long-term cycle performance with retention of 99% discharge capacity and 98% Coulombic efficiency in an all-solid-state Li-metal battery. Theoretical simulations reveal that the incorporation of zwitterionic groups into COF can facilitate the dissociation of strong ion pairs and reconstruct the AA-stacking configuration by dissociative adsorption of Li+ ions on Zwitt-COF producing linear hexagonal ion channels in the Zwitt-COF solid electrolyte. This strategy based on Zwitt-COF can provide an alternative way to construct various solid-state Li batteries.

Effects of hydrothermal pretreatment on methane potential of anaerobic digestion sludge cake of cattle manure containing sawdust as bedding materials.

OBJECTIVE: The purpose of this study was to analyze the effect of the hydrothermal pretreat-ment of anaerobic digestion sludge cake (ADSC) of cattle manure on the solubilization of organic matter and the methane yield to improve the anaerobic digestion efficiency of cattle manure collected from the sawdust pens of cattle. METHODS: Anaerobic digestion sludge cake of cattle manure was thermally pretreated at 160°C, 180°C, 200°C, and 220°C by a hydrothermal pressure reactor, and the biochemical methane potential of ADSC hydrolysate was analyzed. Methane yield recovered by the hydrothermal pretreatment of ADCS was estimated based on mass balance. RESULTS: The chemical oxygen demand solubilization degree (CODs) of the hydrothermal hydrolysate increased to 63.56%, 67.13%, 70.07%, and 66.14% at the hydrothermal reaction temperatures of 160°C, 180°C, 200°C, and 220°C, respectively. Considering the volatile solids content obtained after the hydrothermal pretreatment, the methane of 10.2 Nm3/ton-ADSC was recovered from ADSC of 1.0 ton, and methane yields of ADSC hydrolysate increased to 15.6, 18.0, 17.4, and 17.2 Nm3/ton-ADSC. CONCLUSION: Therefore, the optimal hydrothermal reaction temperature that yielded the maximum methane yield was 180°C based on mass balance, and the methane yield from cattle manure containing sawdust was improved by the hydrothermal pretreatment of ADSC.

Single-cell mapping of combinatorial target antigens for CAR switches using logic gates.

Identification of optimal target antigens that distinguish cancer cells from normal surrounding tissue cells remains a key challenge in chimeric antigen receptor (CAR) cell therapy for tumors with intratumoral heterogeneity. In this study, we dissected tissue complexity to the level of individual cells through the construction of a single-cell expression atlas that integrates ~1.4 million tumor, tumor-infiltrating normal and reference normal cells from 412 tumors and 12 normal organs. We used a two-step screening method using random forest and convolutional neural networks to select gene pairs that contribute most to discrimination between individual malignant and normal cells. Tumor coverage and specificity are evaluated for the AND, OR and NOT logic gates based on the combinatorial expression pattern of the pairing genes across individual single cells. Single-cell transcriptome-coupled epitope profiling validates the AND, OR and NOT switch targets identified in ovarian cancer and colorectal cancer.

Efficacy and Safety of COVID-19 Treatment Using Convalescent Plasma Transfusion: Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials.

This study investigated the efficacy and safety of convalescent plasma (CP) transfusion against the coronavirus disease 2019 (COVID-19) via a systematic review and meta-analysis of randomized controlled trials (RCTs). A total of 5467 articles obtained from electronic databases were assessed; however, only 34 RCTs were eligible after manually screening and eliminating unnecessary studies. The beneficial effect was addressed by assessing the risk ratio (RR) and standardized mean differences (SMDs) of the meta-analysis. It was demonstrated that CP therapy is not effective in improving clinical outcomes, including reducing mortality with an RR of 0.88 [0.76; 1.03] (I2 = 68% and p = 0.10) and length of hospitalization with SMD of -0.47 [-0.95; 0.00] (I2 = 99% and p = 0.05). Subgroup analysis provided strong evidence that CP transfusion does not significantly reduce all-cause mortality compared to standard of care (SOC) with an RR of 1.01 [0.99; 1.03] (I2 = 70% and p = 0.33). In addition, CP was found to be safe for and well-tolerated by COVID-19 patients as was the SOC in healthcare settings. Overall, the results suggest that CP should not be applied outside of randomized trials because of less benefit in improving clinical outcomes for COVID-19 treatment.

Understanding chaos in COVID-19 and its relationship to stringency index: Applications to large-scale and granular level prediction models.

Understanding the underlying and unpredictable dynamics of the COVID-19 pandemic is important. We supplemented the findings of Jones and Strigul (2020) and described the chaotic behavior of COVID-19 using state space plots which depicted the changes in asymptotic behavior and trajectory brought about by the increase or decrease in the number of cases which resulted from the easing or tightening of restrictions and other non-pharmaceutical interventions instituted by governments as represented by the country's stringency index (SI). We used COVID-19 country-wide case count data and analyzed it using convergent cross-mapping (CCM) and found that the SI influence on COVID-19 case counts is high in almost all the countries considered. When we utilized finer granular geographical data ('barangay' or village level COVID-19 case counts in the Philippines), the effects of SI were reduced as the population density increased. The authors believe that the knowledge of the chaotic behavior of COVID-19 and the effects of population density as applied to finer granular geographical data has the potential to generate more accurate COVID-19 non-linear prediction models. This could be used at the local government level to guide strategic and highly targeted COVID-19 policies which are favorable to public health systems but with limited impact to the economy.

Structural and Electronic Modulations of Imidazolium Covalent Organic Framework-Derived Electrocatalysts for Oxygen Redox Reactions in Rechargeable Zn-Air Batteries.

Covalent organic frameworks (COFs) are promising candidates for the controllable design of electrocatalysts. However, bifunctional electrocatalytic activities for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) remain challenging in COFs. In this study, imidazolium-rich COFs (IMCOFs) with well-defined active sites and characteristic three-dimensional assembly structures were readily prepared, and their electronic structures were tuned by Co incorporation to elicit bifunctional electrocatalytic activities for the ORR and OER. The Co nanoparticle-incorporated spherical IMCOF-derived electrocatalyst (CoNP-s-IMCOF) exhibited lower overpotentials for the ORR and OER compared with the atomic Co-incorporated planar IMCOF-derived electrocatalyst (Co-p-IMCOF). Computational simulations revealed that the imidazole carbon sites of CoNP-s-IMCOF rather than the triazine carbons were the active sites for the ORR and OER, and its p-band center downshifted via charge transfer, facilitating the chemisorption of oxygen intermediates during the reactions. A Zn-air battery with CoNP-s-IMCOF exhibited a small voltage gap of 1.3 V with excellent durability for 935 cycles. This approach for control over the three-dimensional assembly and electronic structures of IMCOFs can be extended to the development of diverse catalytic nanomaterials for applications of interest.

Modulating the electrocatalytic activity of N-doped carbon frameworks via coupling with dual metals for Zn-air batteries.

N-Doped carbon electrocatalysts are a promising alternative to precious metal catalysts to promote oxygen reduction reaction (ORR). However, it remains a challenge to design the desired active sites on carbon skeletons in a controllable manner for ORR. Herein, we developed a facile approach based on oxygen-mediated solvothermal radical reaction (OSRR) for preparation of N-doped carbon electrocatalysts with a pre-designed active site and modulated catalytic activity for ORR. In the OSRR, 2-methylimidazole reacted with Co and Mn salts to form an active site precursor (MnCo-MIm) in N-methyl-2-pyrrolidone (NMP) at room temperature. Then, the reaction temperature increased to 140 °C under an oxygen atmosphere to generate NMP radicals, followed by their polymerization with the pre-formed MnCo-MIm to produce Mn-coupled Co nanoparticle-embedded N-doped carbon framework (MnCo-NCF). The MnCo-NCF showed uniform dispersion of nitrogen atoms and Mn-doped Co nanoparticles on the carbon skeleton with micropores and mesopores. The MnCo-NCF exhibited higher electrocatalytic activity for ORR than did a Co nanoparticle only-incorporated carbon framework due to the improved charge transfer from the Mn-doped Co nanoparticles to the carbon skeleton. In addition, the Zn-air battery assembled with MnCo-NCF had superior performance and durability to the battery using commercial Pt/C. This facile approach can be extended for designing carbon electrocatalysts with desired active sites to promote specific reactions.

Whole-Genome and Transcriptome Sequencing Identified NOTCH2 and HES1 as Potential Markers of Response to Imatinib in Desmoid Tumor (Aggressive Fibromatosis): A Phase II Trial Study.

PURPOSE: Desmoid tumor, also known as aggressive fibromatosis, is well-characterized by abnormal Wnt/ß-catenin signaling. Various therapeutic options, including imatinib, are available to treat desmoid tumor. However, the molecular mechanism of why imatinib works remains unclear. Here, we describe potential roles of NOTCH2 and HES1 in clinical response to imatinib at genome and transcriptome levels. MATERIALS AND METHODS: We identified somatic mutations in coding and noncoding regions via whole-genome sequencing. To validate the genetic interaction with expression level in desmoid-tumor condition, we utilized large-scale whole-genome sequencing and transcriptome datasets from the Pan-Cancer Analysis of Whole Genomes project. RNA-sequencing was performed using prospective and retrospective cohort samples to evaluate the expressional relevance with clinical response. RESULTS: Among 20 patients, four (20%) had a partial response and 14 (66.7%) had stable disease, 11 of which continued for ≥ 1 year. With gene-wise functional analyses, we detected a significant correlation between recurrent NOTCH2 noncoding mutations and clinical response to imatinib. Based on Pan-Cancer Analysis of Whole Genomes data analyses, NOTCH2 mutations affect expression levels particularly in the presence of CTNNB1 missense mutations. By analyzing RNA-sequencing with additional desmoid tumor samples, we found that NOTCH2 expression was significantly correlated with HES1 expression. Interestingly, NOTCH2 had no statistical power to discriminate between responders and non-responders. Instead, HES1 was differentially expressed with statistical significance between responders and non-responders. CONCLUSION: Imatinib was effective and well tolerated for advanced desmoid tumor treatment. Our results show that HES1, regulated by NOTCH2, as an indicator of sensitivity to imatinib, and an important therapeutic consideration for desmoid tumor.

Effect of carbon addition on the passivity of hypoeutectic high chromium cast irons.

The effect of adding C on the passivity of hypoeutectic high chromium cast iron (HCCI) was investigated in a pH 8.4 boric-borate buffer solution. The microstructure of HCCI is composed of austenite and carbide phases, whose fractions and chemical compositions are influenced by the amount of C added. Electrochemical and surface analyses revealed that the addition of C in the HCCI increased the defect densities in the n-type and p-type semiconductive oxide layers on the austenite and carbide phases, respectively.

Ultrathin WO3 Nanosheets Converted from Metallic WS2 Sheets by Spontaneous Formation and Deposition of PdO Nanoclusters for Visible Light-Driven C-C Coupling Reactions.

It is not facile to obtain ultrathin two-dimensional (2D) WO3 nanosheets through the exfoliation of their bulk counterpart in solution due to strong covalent interaction between interlayers. In addition, they require additional functionalization with cocatalysts to expand their applicability in photocatalytic organic reactions owing to their insufficient conduction band edge position. Here, we report a chemical approach for the simultaneous production and functionalization of ultrathin 2D WO3 nanosheets through the direct conversion of metallic WS2 nanosheets, accomplished by the spontaneous formation and deposition of PdO nanoclusters on the nanosheet surface in H2O. When chemically exfoliated metallic WS2 nanosheets were simply mixed with K2PdCl4 in H2O under mild conditions (50 °C, 1 h), they were converted to semiconducting WO3 nanosheets on which PdO nanoclusters of a uniform size (∼3 nm) were spontaneously formed, leading to the production of PdO-functionalized ultrathin WO3 (PdO@WO3) nanohybrids. The conversion yield of WO3 nanosheets from metallic WS2 nanosheets increased with increasing coverage of PdO nanoclusters on the nanosheet surface. In addition, the conversion of WO3 nanosheets induced by PdO nanocluster formation was effective only in H2O but not in organic solvents, such as N-methylpyrrolidone and acetonitrile. A mechanical study suggests that the chemisorption of hydrated Pd precursors on the chalcogens of metallic WS2 nanosheets leads to their facile oxidation by water molecules, producing WO3 nanosheets covered with PdO nanoclusters. The as-prepared PdO@WO3 nanosheets exhibited excellent photocatalytic activity and recyclability in Suzuki cross-coupling reactions of various aryl halides under visible light irradiation.

Improved astaxanthin production by Xanthophyllomyces dendrorhous SK984 with oak leaf extract and inorganic phosphate supplementation.

Astaxanthin is widely used in food, feed and nutraceutical industries. Xanthophyllomyces dendrorhous is one of the most promising natural sources of astaxanthin. However, the astaxanthin yield in the wild-type X. dendrorhous is considered low for industrial application. In the present study, X. dendrorhous ATCC 66272 was subjected to two-staged mutagenesis: (i) UV light and (ii) N-methyl-N'-nitro-N-nitroso-guanidine (NTG) toward attaining higher astaxanthin yield. The UV-irradiation mutant, X. dendrorhous SK974 showed 1.7-fold (1.07 mg/g) higher astaxanthin production as compared with the wild-type strain (0.65 mg/g). The UV mutant strain was then treated with NTG, designated as X. dendrorhous SK984, displayed further 1.4-fold (1.45 mg/g) higher astaxanthin production. Furthermore, the oak leaf extract (5%, v/v) and inorganic phosphate (KH2PO4, 3 mM) supplementation resulted about 1.4-fold (1.98 mg/g) higher astaxanthin production as compared with control (1.45 mg/g) in X. dendrorhous SK984. These findings serve as a platform suggesting that intersecting approaches might be aimed toward systematically enhanced astaxanthin production.

Factors affecting KRAS mutation detection in colorectal cancer tissue.

BACKGROUND: With the recent development of molecular tests for various biomarkers, it has become even more important to prepare adequate tissue samples. However, little is known about how the effect of cold ischemia time or formalin fixation time can affect KRAS mutation detection in colorectal cancer. METHODS: This study included the results of KRAS mutation tests for colorectal cancer in 401 specimens. We investigated clinicopathologic factors that may affect DNA quality of formalin-fixed, paraffin-embedded (FFPE) tissue including specimen type, cold ischemia time, and formalin fixation time and assessed the detection rate of the KRAS mutation in samples with varying DNA quality. RESULTS: Sample DNA quality for KRAS mutation test was better in biopsy specimens, which showed markedly shorter cold ischemia time and shorter formalin fixation time compared to resection specimens. A cold ischemia time of one hour or less was associated with better sample DNA quality. But the formalin fixation time was not a significant factor when it fell within the range performed in routine pathology diagnosis. When prolonged formalin fixation was tested, we confirmed that the specimen DNA quality gradually got worse from one month to three months. CONCLUSIONS: The biopsy specimens showed better sample DNA quality for KRAS mutation test compared to resection specimens. In a routine diagnostic pathology setting, the cold ischemia time was an important factor affecting DNA quality and the formalin fixation had a wide time range for optimal DNA quality.

Phytochemicals and antioxidant capacity of some tropical edible plants.

OBJECTIVE: To find biological functions such as antibacterial and antioxidant activities in several tropical plants and to investigate the possibility of antibiotic substitute agents to prevent and treat diseases caused by pathogenic bacteria. METHODS: Plants such as Poncirus trifoliata fruit (Makrut), Zingiber officinale Rosc (Khing), Areca catechu L. (Mak), Solanum melongena L. I (Makkhuayao), and Solanum melongena L. II (Makhurapro) were extracted by methanol, n-hexane, chloroform, ethyl acetate, butanol and water. The free radical scavenging activities were measured using 2-diphenyl-2-picryl hydrazyl photometric assay. Antibacterial activities with a minimum inhibitory concentration (MIC) were observed by agar diffusion assay against pathogenic strains of Escherichia coli, Burkholderia sp., Haemopilus somnus, Haemopilus parasuis, Clostridium perfringens, and Pantoea agglomerans. RESULTS: Poncirus trifoliata fruit methanol extract showed antibacterial activities against gram-negative and gram-positive pathogens. Additionally, this showed the strongest antibacterial activity against Burkholderia sp. and Haemopilus somnus with MIC 131 µg/mL, respectively. Areca catechu L. water extract showed antibacterial activities against Burkholderia sp., Haemopilus somnus, and Haemopilus parasuis. The MIC value for Haemopilus parasuis was 105 µg/mL in this. Antioxidant activity of Zingiber officinale Rosc n-hexane extract showed 2.23 mg/mL effective concentration 50% (EC50) value was the highest activity among tropical plants extracts. Total polyphenol content in Zingiber officinale Rosc methanol extract was 48.4 µg/mL and flavonoid content was 22.1 µg/mL showed the highest values among tested plants extracts. CONCLUSION: Taken together, these results suggest that tropical plants used in this study may have a potential benefit as an alternative antibiotics agent through their antibacterial and antioxidant activities.

Heartwood extract of Rhus verniciflua Stokes and its active constituent fisetin attenuate vasoconstriction through calcium-dependent mechanism in rat aorta.

Rhus verniciflua Stokes (RVS) exert cardiovascular protective activity by promoting blood circulation, but its active ingredients and underlying mechanism have yet to be identified. This study investigated the vascular effects of RVS, focusing on vasoconstriction and smooth muscle Ca(2+) signaling. RVS heartwood extract attenuated contraction of aortic rings induced by the vasoconstrictors serotonin and phenylephrine, and inhibited the Ca(2+) signaling evoked by serotonin in vascular smooth muscle cells. Subsequent activity-guided fractionation identified fisetin as an active constituent exerting a Ca(2+) inhibitory effect. Fisetin could inhibit major Ca(2+) mobilization pathways including extracellular Ca(2+) influx mediated by the L-type voltage-gated Ca(2+) channel, Ca(2+) release from the intracellular store and store-operated Ca(2+) entry. In accordance with Ca(2+) inhibitory effect, fisetin attenuated vasoconstriction by serotonin and phenylephrine. These results suggest that the anticontractile effect, which is presumably mediated by inhibition of Ca(2+) signaling, may contribute to the improvement of blood circulation by RVS.

Antiplatelet effects of Rhus verniciflua stokes heartwood and its active constituents--fisetin, butein, and sulfuretin--in rats.

Rhus verniciflua stokes (RVS) is known to promote blood circulation by preventing blood stasis, although the active ingredients and the underlying mechanism are unclear. Platelets are the primary cells that regulate circulation and contribute to the development of diverse cardiovascular diseases by aggregation and thrombosis. The study assessed the antiplatelet activity of RVS and sought to identify the active constituents. Pretreatment of washed platelets with RVS heartwood extract blunted the aggregatory response of platelets to collagen. In the subfractions, fisetin, butein, and sulfuretin were identified as effective inhibitors of platelet aggregation by collagen, thrombin, and adenosine-5'-diphosphate. Antiplatelet activities of all three compounds were concentration dependent, and fisetin had longer in vitro duration of action compared with butein or sulfuretin. Extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase activation by collagen was prevented by fisetin, whereas butein and sulfuretin failed to inhibit ERK and p38 activation was not affected by any of the compounds. Rats orally administered 100 mg/(kg·day(-1)) fisetin for 7 days were resistant to arterial thrombosis, although total extract of RVS heartwood exhibited little effect at a dose of 1000 mg/(kg·day(-1)). RVS heartwood may have cardiovascular protective activity by inhibiting platelet aggregation. The active constituents are fisetin, butein, and sulfuretin, and fisetin is orally effective against thrombosis.

Protective effects of methoxyflavone derivatives from black galingale against glutamate induced neurotoxicity in primary cultured rat cortical cells.

To examine the neuroprotective effects of black galingale, its protection was tested against glutamate-induced neurotoxicity in primary cortical cultured neurons. It was found that an aqueous extract of this medicinal plant exhibited significant protection against glutamate-induced toxicity in primary cultured rat cortical cells. In order to clarify the neuroprotective mechanism(s) of this observed effect, isolation was performed to seek and identify active fractions and components. By such fractionation, bioactive methoxyflavone derivatives were isolated from the methanol extracts from the air-dried rhizomes of black galingale. 5-Hydroxy-3,7,3',4'-tetramethoxyflavone exhibited significant neuroprotective activities against glutamate-induced toxicity, exhibiting cell viability of about 60-70%, at concentrations ranging from 0.1 µm to 10 µm. Therefore, the neuroprotective effect of black galingale might be due to the inhibition of glutamate-induced toxicity by the methoxyflavone derivatives it contains.