IC50, Half-maximal inhibitory concentration

  • 文章类型: Journal Article
    Lophatherumgracile(L.gracile)长期以来一直被用作功能性食品和草药。以前的研究已经证明,L.gracile的提取物减弱炎症反应和抑制SARS-CoV-2复制;然而,潜在的活性成分尚未确定。本研究调查了L.gracile的生物活性成分。发现L.gracile的黄酮C-糖苷在抗炎和抗病毒作用中占主导地位。开发了一种简单的基于色谱的方法,以从L.gracile中获得富含黄酮C-糖苷的提取物(FlavoLG)。FlavoLG及其主要的黄酮C-糖苷isoorientin被证明可以限制呼吸爆发和激活的人中性粒细胞中中性粒细胞胞外陷阱的形成。FlavoLG和isoorientin还显示通过干扰SARS-CoV-2尖峰在ACE2上的结合来抑制SARS-CoV-2假病毒感染。这些结果提供了科学证据,表明L.gracile作为治疗中性粒细胞相关COVID-19的潜在补充剂的功效。
    Lophatherum gracile (L. gracile) has long been used as a functional food and herbal medicine. Previous studies have demonstrated that extracts of L. gracile attenuate inflammatory response and inhibit SARS-CoV-2 replication; however, the underlying active constituents have yet to be identified. This study investigated the bioactive components of L. gracile. Flavone C-glycosides of L. gracile were found to dominate both anti-inflammatory and antiviral effects. A simple chromatography-based method was developed to obtain flavone C-glycoside-enriched extract (FlavoLG) from L. gracile. FlavoLG and its major flavone C-glycoside isoorientin were shown to restrict respiratory bursts and the formation of neutrophil extracellular traps in activated human neutrophils. FlavoLG and isoorientin were also shown to inhibit SARS-CoV-2 pseudovirus infection by interfering with the binding of the SARS-CoV-2 spike on ACE2. These results provide scientific evidence indicating the efficacy of L. gracile as a potential supplement for treating neutrophil-associated COVID-19.
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  • 文章类型: Journal Article
    Damnacanthal是蒽醌,提取,并从泰国的巴林达根中纯化。本研究旨在测量急性口服毒性,并研究达纳沙尔在结直肠肿瘤发生中的抗癌活性。我们发现Damnacanthal以剂量和时间依赖性的方式抑制人结直肠癌细胞的生长。Damnacanthal对大肠癌细胞的生长抑制作用优于5-FU作为阳性对照,随着细胞周期蛋白cyclinD1的下调。同样,Damnacanthal口服治疗可有效抑制裸鼠结肠直肠肿瘤异种移植物的生长,根据肿瘤大小以及生物发光的表达,与5-FU相比约高2-3倍。此外,根据OECD第423号指南,小鼠急性口服毒性研究显示damnacanthal的毒性相对较低,LD50临界值为2500mg/kg。这些结果揭示了作为抗结肠直肠癌药物的天然Damnacanthal化合物的潜在治疗活性。
    Damnacanthal is an anthraquinone, extracted, and purified from the root of Morinda citrifolia in Thailand. This study aimed to measure acute oral toxicity and to investigate the anticancer activity of damnacanthal in colorectal tumorigenesis. We found that the growth of human colorectal cancer cells was inhibited by damnacanthal in a dose- and a time-dependent manner. The growth inhibitory effect of damnacanthal was better than that of 5-FU used as a positive control in colorectal cancer cells, along with the downregulation of cell cycle protein cyclin D1. Similarly, an oral treatment of damnacanthal effectively inhibited the growth of colorectal tumor xenografts in nude mice, which was approximately 2-3-fold higher as compared to 5-FU by tumor size as well as expression of bioluminescence. Furthermore, the study of acute oral toxicity in mice exhibited a relatively low toxicity of damnacanthal with a LD50 cut-off value of 2500 mg/kg according to OECD Guideline 423. These results reveal the potential therapeutic activity of a natural damnacanthal compound as an anti-colorectal cancer drug.
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  • 文章类型: Journal Article
    自2019年12月以来,严重急性呼吸道综合症冠状病毒2(SARS-CoV-2)已成为一种新兴的人类病毒,世界人口易患2019年冠状病毒病(COVID-19)。SARS-CoV-2比以前的冠状病毒具有更高的传播能力,由核糖核酸(RNA)病毒性质相关的高突变率,导致SARS-CoV-2变体在全球传播时出现。中和抗体被鉴定为针对COVID-19的即时和直接作用治疗剂。单结构域抗体(sdAb),作为具有非复杂结构和内在稳定性的小生物分子,可以获得与常规抗体相当的抗原结合能力,作为一种有吸引力的中和溶液。SARS-CoV-2刺突蛋白附着于肺上皮细胞上的人血管紧张素转换酶2(ACE2)受体以引发病毒感染,作为潜在的治疗靶点。sdAb已经显示出广泛的中和对SARS-CoV-2的各种突变,有效阻止和预防感染,同时有效阻止突变逃逸。此外,sdAb可以发展成为针对COVID-19的多价抗体或吸入性生物治疗剂。
    With severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as an emergent human virus since December 2019, the world population is susceptible to coronavirus disease 2019 (COVID-19). SARS-CoV-2 has higher transmissibility than the previous coronaviruses, associated by the ribonucleic acid (RNA) virus nature with high mutation rate, caused SARS-CoV-2 variants to arise while circulating worldwide. Neutralizing antibodies are identified as immediate and direct-acting therapeutic against COVID-19. Single-domain antibodies (sdAbs), as small biomolecules with non-complex structure and intrinsic stability, can acquire antigen-binding capabilities comparable to conventional antibodies, which serve as an attractive neutralizing solution. SARS-CoV-2 spike protein attaches to human angiotensin-converting enzyme 2 (ACE2) receptor on lung epithelial cells to initiate viral infection, serves as potential therapeutic target. sdAbs have shown broad neutralization towards SARS-CoV-2 with various mutations, effectively stop and prevent infection while efficiently block mutational escape. In addition, sdAbs can be developed into multivalent antibodies or inhaled biotherapeutics against COVID-19.
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  • 文章类型: Journal Article
    糖尿病性周围神经病变(DPN)是一种逐渐变得更加普遍的医学病症。DPN的根本原因仍然未知,尽管有几种假设的机制。目前有药物治疗用于控制疼痛,但它们的疗效在很大程度上并不令人满意,并且通常伴有严重的不良反应。这篇综述将探索治疗DPN的新的潜在靶点的证据。烟碱乙酰胆碱受体(nAChRs)的配体,特别是α42激动剂和α9α10拮抗剂。
    Diabetic peripheral neuropathy (DPN) is a medical condition that is progressively becoming more prevalent. The underlying cause of DPN is still unknown, although there have been several hypothesized mechanisms. There are current pharmaceutical treatments used to manage the pain, but their efficacy is largely unsatisfactory and are often associated with serious adverse effects. This review will explore the evidence of a new potential target for treating DPN, the ligands for nicotinic acetylcholine receptors (nAChRs), specifically α4ꞵ2 agonists and α9α10 antagonists.
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  • 文章类型: Journal Article
    ω-皂苷抑制N型电压门控钙(CaV2.2)通道,并表现出减轻神经性疼痛的功效,但治疗指数低。这里,我们合成并表征了一种新型ω-芋螺毒素,来自Conusbullatus的Bu8,由25个氨基酸残基和三个二硫键组成。Bu8选择性和有效地抑制由HEK293T细胞中表达的大鼠CaV2.2介导的去极化激活的Ba2电流(IC50=89nmol/L)。Bu8的效力是ω-芋螺毒素MVIIA的两倍,目前用于治疗严重慢性疼痛的ω-芋螺毒素。它在热板和乙酸扭动的动物疼痛模型中也显示出有效的镇痛活性,但对小鼠运动功能的副作用较小,对金鱼的毒性较低。其较低的副作用可能归因于其更快的结合速率和更高的回收率。NMR结构表明Bu8含有小的不规则的三β-链。Bu8Ala突变体和Bu8/MVIIA杂合突变体的结构-活性关系表明,CaV2.2与Bu8的环1和环2中的氨基酸残基的结合模式不同于MVIIA。这项研究描述了一部小说,更有效的ω-芋螺毒素,为设计CaV2.2拮抗剂提供了新的见解。
    ω-Conotoxins inhibit N-type voltage-gated calcium (CaV2.2) channels and exhibit efficacy in attenuating neuropathic pain but have a low therapeutic index. Here, we synthesized and characterized a novel ω-conotoxin, Bu8 from Conus bullatus, which consists of 25 amino acid residues and three disulfide bridges. Bu8 selectively and potently inhibits depolarization-activated Ba2+ currents mediated by rat CaV2.2 expressed in HEK293T cells (IC50 = 89 nmol/L). Bu8 is two-fold more potent than ω-conotoxin MVIIA, a ω-conotoxin currently used for the treatment of severe chronic pain. It also displays potent analgesic activity in animal pain models of hot plate and acetic acid writhing but has fewer side effects on mouse motor function and lower toxicity in goldfish. Its lower side effects may be attributed to its faster binding rate and higher recovery ratios. The NMR structure demonstrates that Bu8 contains a small irregular triple β-strand. The structure-activity relationships of Bu8 Ala mutants and Bu8/MVIIA hybrid mutants demonstrate that the binding mode of CaV2.2 with the amino acid residues in loop 1 and loop 2 of Bu8 is different from that of MVIIA. This study characterizes a novel, more potent ω-conotoxin and provides new insights for designing CaV2.2 antagonists.
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  • 文章类型: Journal Article
    UNASSIGNED: Despite known clinical risk factors, predicting anthracycline cardiotoxicity remains challenging.
    UNASSIGNED: This study sought to develop a clinical and genetic risk prediction model for anthracycline cardiotoxicity in childhood cancer survivors.
    UNASSIGNED: We performed exome sequencing in 289 childhood cancer survivors at least 3 years from anthracycline exposure. In a nested case-control design, 183 case patients with reduced left ventricular ejection fraction despite low-dose doxorubicin (≤250 mg/m2), and 106 control patients with preserved left ventricular ejection fraction despite doxorubicin >250 mg/m2 were selected as extreme phenotypes. Rare/low-frequency variants were collapsed to identify genes differentially enriched for variants between case patients and control patients. The expression levels of 5 top-ranked genes were evaluated in human induced pluripotent stem cell-derived cardiomyocytes, and variant enrichment was confirmed in a replication cohort. Using random forest, a risk prediction model that included genetic and clinical predictors was developed.
    UNASSIGNED: Thirty-one genes were differentially enriched for variants between case patients and control patients (p < 0.001). Only 42.6% case patients harbored a variant in these genes compared to 89.6% control patients (odds ratio: 0.09; 95% confidence interval: 0.04 to 0.17; p = 3.98 × 10-15). A risk prediction model for cardiotoxicity that included clinical and genetic factors had a higher prediction accuracy and lower misclassification rate compared to the clinical-only model. In vitro inhibition of gene-associated pathways (PI3KR2, ZNF827) provided protection from cardiotoxicity in cardiomyocytes.
    UNASSIGNED: Our study identified variants in cardiac injury pathway genes that protect against cardiotoxicity and informed the development of a prediction model for delayed anthracycline cardiotoxicity, and it also provided new targets in autophagy genes for the development of cardio-protective drugs. (Preventing Cardiac Sequelae in Pediatric Cancer Survivors [PCS2]; NCT01805778).
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  • 文章类型: Journal Article
    微生物表面活性剂是由亲水和疏水结构域组成的两亲分子,这允许不同极性的两个流体相的分配。它们分为两大类:生物乳化剂和生物表面活性剂,取决于它们的分子量。微生物表面活性剂根据其化学性质和产生生物体而存在于各种类别中。这些生物分子是由包括真菌在内的各种微生物产生的,细菌,和酵母。它们的生产受到底物类型的显著影响,发酵技术和微生物菌株。由于微生物固有的多功能特性和各种合成能力,微生物表面活性剂比化学表面活性剂更适合用于各种工业和生物医学应用,包括生物修复,油回收;作为洗衣配方中的补充剂,作为食品和化妆品工业中的乳液稳定剂,以及医药中的治疗剂。本综述讨论了微生物表面活性剂作为各种生物技术应用的有前途和替代的广泛功能生物分子的生产。
    Microbial surfactants are amphipathic molecules that consist of hydrophilic and hydrophobic domains, which allow partition of two fluid phases of varying degree of polarity. They are classified into two main groups: bioemulsifier and biosurfactant, depending on their molecular weight. Microbial surfactants occur in various categories according to their chemical nature and producing organisms. These biomolecules are produced by diverse groups of microorganisms including fungi, bacteria, and yeasts. Their production is significantly influenced by substrate type, fermentation technology and microbial strains. Owing to inherent multifunctional properties and assorted synthetic aptitude of the microbes, microbial surfactants are mostly preferred than their chemical counterparts for various industrial and biomedical applications including bioremediation, oil recovery; as supplements in laundry formulations and as emulsion-stabilizers in food and cosmetic industries as well as therapeutic agents in medicine. The present review discusses on production of microbial surfactants as promising and alternative broad-functional biomolecules for various biotechnological applications.
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  • 文章类型: Journal Article
    设计和筛选当前严重急性呼吸综合征-冠状病毒-2(SARS-CoV-2)大流行的治疗方法的许多努力都集中在通过破坏血管紧张素转换酶-2(ACE2)与SARS-CoV-2刺突蛋白的结合来抑制病毒宿主细胞的进入。这项工作着重于通过假设的基于α5β1整合素的机制抑制SARS-CoV-2进入的潜力,并表明抑制刺突蛋白与α5β1整合素(ACE2)的相互作用以及α5β1整合素和ACE2之间的相互作用使用新型分子(ATN-161)代表了治疗冠状病毒病19的有希望的方法。
    Many efforts to design and screen therapeutics for the current severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) pandemic have focused on inhibiting viral host cell entry by disrupting angiotensin-converting enzyme-2 (ACE2) binding with the SARS-CoV-2 spike protein. This work focuses on the potential to inhibit SARS-CoV-2 entry through a hypothesized α5β1 integrin-based mechanism and indicates that inhibiting the spike protein interaction with α5β1 integrin (+/- ACE2) and the interaction between α5β1 integrin and ACE2 using a novel molecule (ATN-161) represents a promising approach to treat coronavirus disease-19.
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  • 文章类型: Journal Article
    Delonixregia(Bojer前胡克。)Raf。,决明子瘘管和紫薇是三种产生五颜六色花朵的观赏植物。本研究旨在评估来自Delonixregia(DrFME)的花的甲醇提取物的植物化学物质和生物活性,决明子瘘(CfFME),和紫薇(LsFME)。定性筛选时,确认了不同程度的十种不同化学类别的存在。在定量测定期间,LsFME具有最高的总酚含量(418.0mg/g),类黄酮(50.8mg/g),单宁(256.3mg/g)含量。提取物以浓度依赖性方式显示出优异的抗氧化能力,LsFME显示出最低的IC50值(41.51μg/mL)。LsFME在2.95分钟使实验蠕虫瘫痪,并在3.96分钟杀死。发现DrFME在溶栓(35.5%凝块溶解)和抗凝血活性方面更有效。对于所有提取物发现的可忽略的溶血活性(IC50>200μg/mL),这表明它们的潜在毒性较小。体内实验显示,在400mg/kg体重剂量下,CfFME具有最高的镇痛(64.34%疼痛抑制)活性,而LsFME具有最高的止泻(70.27%抑制)和抗高血糖(46.94%抑制)活性。这项研究表明存在植物化学物质和潜在的生物活性,这表明这些花可能被用作植物化学物质的来源以及安全有效的天然药物。
    Delonix regia (Bojer ex Hook.) Raf., Cassia fistula L. and Lagerstroemia speciosa L. are three ornamental plants that produce colorful flowers. The present study aimed to evaluate the phytochemicals and bioactivities of methanolic extracts of flowers from Delonix regia (DrFME), Cassia fistula (CfFME), and Lagerstroemia speciosa (LsFME). The presence of ten different chemical classes in varying degrees was confirmed while qualitatively screened. During quantitative determination, LsFME possesses the highest amount of total phenolic (418.0 mg/g), flavonoid (50.8 mg/g), and tannin (256.3 mg/g) contents. The extracts showed excellent antioxidant capacity in a concentration-dependent manner with the lowest IC50 value (41.51 μg/mL) displayed by LsFME. LsFME paralyzed the experimental worms at 2.95 min and killed at 3.96 min. DrFME was found to be more effective in thrombolytic (35.5% clot lysis) and anticoagulant activities. Negligible hemolytic activity (IC50 > 200 μg/mL) found for all extracts which suggest their less potential toxicity. The in vivo experiments revealed that the CfFME has the highest analgesic (64.34% pain inhibition) activity while LsFME has the highest antidiarrheal (70.27% inhibition) and antihyperglycemic (46.94% inhibition) activities at 400 mg/kg of body weight doses. This study has shown the presence of phytochemicals and potential bioactivities which indicates the possibility of these flowers to be used as a source of phytochemicals as well as safe and effective natural medicine.
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  • 文章类型: Journal Article
    精氨酸酶-1是催化L-精氨酸水解成L-鸟氨酸和尿素的锰依赖性金属酶。精氨酸酶-1由促进肿瘤免疫抑制的肿瘤浸润性骨髓细胞大量表达,通过抑制精氨酸酶-1来缓解。我们已经表征了精氨酸酶-1参考抑制剂(2S)-2-氨基-6-硼己酸(ABH)和Nω-羟基-去甲-精氨酸(nor-NOHA)的效力,并研究了它们的pH依赖性和结合动力学。为了更好地了解精氨酸酶-1的高pH最佳值及其pH依赖性抑制的结构变化,我们在pH7.0和9.0下测定了人精氨酸酶-1/ABH复合物的晶体结构。这些结构表明,在增加的pH值,锰团簇呈现更对称的配位结构,这可能有助于其催化活性的增加。此外,我们表明ABH的结合涉及靠近锰簇的钠离子的存在。我们还研究了正在研究的新药CB-1158(INCB001158)。该抑制剂在pH7.4时具有低纳摩尔效力,并且比ABH和nor-NOHA增加了精氨酸酶-1的热稳定性。此外,CB-1158在pH9.5和7.4下显示出缓慢的缔合和解离动力学,如表面等离子体共振所示。CB-1158的有效特性可能是由于其与ABH相比增加的刚性以及形成了额外的氢键网络,如通过分离精氨酸酶-1/CB-1158晶体结构所观察到的。
    Arginase-1 is a manganese-dependent metalloenzyme that catalyzes the hydrolysis of L-arginine into L-ornithine and urea. Arginase-1 is abundantly expressed by tumor-infiltrating myeloid cells that promote tumor immunosuppression, which is relieved by inhibition of Arginase-1. We have characterized the potencies of the Arginase-1 reference inhibitors (2S)-2-amino-6-boronohexanoic acid (ABH) and N ω-hydroxy-nor-L-arginine (nor-NOHA), and studied their pH-dependence and binding kinetics. To gain a better understanding of the structural changes underlying the high pH optimum of Arginase-1 and its pH-dependent inhibition, we determined the crystal structure of the human Arginase-1/ABH complex at pH 7.0 and 9.0. These structures revealed that at increased pH, the manganese cluster assumes a more symmetrical coordination structure, which presumably contributes to its increase in catalytic activity. Furthermore, we show that binding of ABH involves the presence of a sodium ion close to the manganese cluster. We also studied the investigational new drug CB-1158 (INCB001158). This inhibitor has a low-nanomolar potency at pH 7.4 and increases the thermal stability of Arginase-1 more than ABH and nor-NOHA. Moreover, CB-1158 displays slow association and dissociation kinetics at both pH 9.5 and 7.4, as indicated by surface plasmon resonance. The potent character of CB-1158 is presumably due to its increased rigidity compared to ABH as well as the formation of an additional hydrogen-bond network as observed by resolution of the Arginase-1/CB-1158 crystal structure.
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