Catechin

儿茶素
  • 文章类型: Journal Article
    治疗药物的快速药物清除和脱靶效应可导致低生物利用度和全身性副作用,并严重限制炎症性肠病(IBD)的治疗效果。这里,我们提出了一种基于口服镓(Ga)基液态金属(LM)纳米药物的扩增靶向策略,以有效消除活性氧和氮物种(RONS)并调节失调的微生物组,以缓解IBD。利用多酚结构良好的粘合活性和配位能力,表没食子儿茶素没食子酸酯(EGCG)用于包封LM以构建制剂(LM-EGCG)。粘附到发炎的组织后,EGCG不仅消除了RONS,而且还捕获了解离的Ga以形成EGCG-Ga复合物以进行增强积累。滞留的复合材料保护肠道屏障和调节肠道微生物群,以恢复无序的肠内微环境,从而缓解IBD。出乎意料的是,LM-EGCG显着减少了大肠杆菌_志贺氏菌种群,同时增加了Akkermansia和双歧杆菌的丰度,对葡聚糖硫酸钠诱导的结肠炎产生良好的治疗效果。
    Rapid drug clearance and off-target effects of therapeutic drugs can induce low bioavailability and systemic side effects and gravely restrict the therapeutic effects of inflammatory bowel diseases (IBDs). Here, we propose an amplifying targeting strategy based on orally administered gallium (Ga)-based liquid metal (LM) nano-agents to efficiently eliminate reactive oxygen and nitrogen species (RONS) and modulate the dysregulated microbiome for remission of IBDs. Taking advantage of the favorable adhesive activity and coordination ability of polyphenol structure, epigallocatechin gallate (EGCG) is applied to encapsulate LM to construct the formulations (LM-EGCG). After adhering to the inflamed tissue, EGCG not only eliminates RONS but also captures the dissociated Ga to form EGCG-Ga complexes for enhancive accumulation. The detained composites protect the intestinal barrier and modulate gut microbiota for restoring the disordered enteral microenvironment, thereby relieving IBDs. Unexpectedly, LM-EGCG markedly decreases the Escherichia_Shigella populations while augmenting the abundance of Akkermansia and Bifidobacterium, resulting in favorable therapeutic effects against the dextran sulfate sodium-induced colitis.
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  • 文章类型: Journal Article
    Bcl-2蛋白以其抗凋亡特性而闻名,与癌症的发病机制有关。鉴定负责促进细胞存活和发育改善的主要基因已经为防止恶性肿瘤进展中的细胞死亡提供了令人信服的证据。大量的研究提供了证据,表明在恶性细胞中Bcl-2的丰度更高,提示抑制Bcl-2表达可能是一种可行的癌症治疗方法。在这项研究中,我们使用包含中药(TCM)成分的数据库获得了化合物集合。最初,我们建立了药效基团模型,并利用该模型在TCM数据库中搜索潜在化合物.选择适应性评分超过0.75的化合物用于进一步分析。吸收,Distribution,代谢,排泄,和毒性(ADMET)分析确定了具有良好治疗特性的六种化合物。对成功通过基于药效学模型的初始筛选过程的化合物进行进一步评价。采用超精密(XP)对接来鉴定具有最有利的XP对接得分的化合物。使用分子力学广义玻恩表面积(MM-GBSA)方法进一步分析以计算总自由结合能。通过100ns姜黄素和表没食子儿茶素没食子酸酯(EGCG)的分子动力学模拟评估了预期配体分子与靶蛋白Bcl-2之间的结合能。这项研究的发现证明了当与配体EGCG结合时有效抑制Bcl-2功能的分子结构的鉴定。因此,这一发现为开发能够有效解决炎症和肿瘤疾病的药物提供了新的途径。
    The protein Bcl-2, well-known for its anti-apoptotic properties, has been implicated in cancer pathogenesis. Identifying the primary gene responsible for promoting improved cell survival and development has provided compelling evidence for preventing cellular death in the progression of malignancies. Numerous research studies have provided evidence that the abundance of Bcl-2 is higher in malignant cells, suggesting that suppressing Bcl-2 expression could be a viable therapeutic approach for cancer treatment. In this study, we acquired a compound collection using a database that includes constituents from Traditional Chinese Medicine (TCM). Initially, we established a pharmacophore model and utilized it to search the TCM database for potential compounds. Compounds with a fitness score exceeding 0.75 were selected for further analysis. The Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) analysis identified six compounds with favorable therapeutic characteristics. The compounds that successfully passed the initial screening process based on the pharmacodynamic model were subjected to further evaluation. Extra-precision (XP) docking was employed to identify the compounds with the most favorable XP docking scores. Further analysis using the Molecular Mechanics Generalized Born Surface Area (MM-GBSA) method to calculate the overall free binding energy. The binding energy between the prospective ligand molecule and the target protein Bcl-2 was assessed by a 100 ns molecular dynamics simulation for curcumin and Epigallocatechin gallate (EGCG). The findings of this investigation demonstrate the identification of a molecular structure that effectively inhibits the functionality of the Bcl-2 when bound to the ligand EGCG. Consequently, this finding presents a novel avenue for the development of pharmaceuticals capable of effectively addressing both inflammatory and tumorous conditions.
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  • 文章类型: Journal Article
    本研究旨在探讨负载儿茶素的壳聚糖海藻酸盐纳米粒(NPs)对氯化铝(AlCl3)诱导的阿尔茨海默病(AD)大鼠模型认知功能的影响。通过离子凝胶化(IG)方法合成了儿茶素-壳聚糖-海藻酸盐纳米载体。用Zetasizer纳米系统进行了物理化学表征,扫描电子显微镜,和傅里叶变换红外光谱。实验在六组雄性Wistar大鼠上进行21天。对照组,AlCl3治疗组,儿茶素组,纳米载体组,治疗组1(AlCl3+儿茶素),和治疗组2(AlCl3+纳米载体)。通过Morris水迷宫(MWM)测试进行行为研究。此外,在研究结束时通过标准程序确定氧化指数水平和乙酰胆碱酯酶(AChE)活性。AlCl3诱导AChE活性显著增加,海马中过氧化氢酶(CAT)和总抗氧化能力(TAC)的水平显着降低。此外,观察到AlCl3对MWM测试的行为参数的显着影响。两种形式的儿茶素均显着提高了AChE活性,氧化生物标志物,空间记忆,和学习。本研究表明,在雄性Wistar大鼠中,服用载有儿茶素的壳聚糖-海藻酸盐NP是针对AD行为和化学改变的有益治疗选择。
    The present study aimed to investigate the effect of catechin-loaded Chitosan-Alginate nanoparticles (NPs) on cognitive function in an aluminum chloride (AlCl3)-induced rat model of Alzheimer\'s disease (AD). The Catechin-loaded Chitosan-Alginate nanocarriers were synthesized through ionotropic gelation (IG) method. Physio-chemical characterization was conducted with the Zetasizer Nano system, the scanning electron microscope, and the Fourier transform infrared spectroscopy. The experiments were performed over 21 days on six groups of male Wistar rats. The control group, AlCl3 treated group, Catechin group, nanocarrier group, treatment group 1 (AlCl3 + Catechin), and treatment group 2 (AlCl3 + nanocarrier). A behavioral study was done by the Morris water maze (MWM) test. In addition, the level of oxidative indices and acetylcholine esterase (AChE) activity was determined by standard procedures at the end of the study. AlCl3 induced a significant increase in AChE activity, along with a significant decrease in the level of Catalase (CAT) and total antioxidant capacity (TAC) in the hippocampus. Moreover, the significant effect of AlCl3 was observed on the behavioral parameters of the MWM test. Both forms of Catechin markedly improved AChE activity, oxidative biomarkers, spatial memory, and learning. The present study indicated that the administration of Catechin-loaded Chitosan-Alginate NPs is a beneficial therapeutic option against behavioral and chemical alteration of AD in male Wistar rats.
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  • 文章类型: Journal Article
    来自农业食品废物的多酚代表了生物活性分子的有价值的来源,可以回收以用于其功能特性。另一种选择是使用它们作为起始材料,通过半合成产生具有新的更好性能的分子。鳄梨果皮中富含原花色素(PAC)的提取物用于在苯酚和硫醇亲核试剂的存在下通过酸裂解制备表儿茶素的几种半合成衍生物。使用一步离心分配色谱(CPC)成功纯化了该反应形成的加合物,并通过色谱和光谱法进行了鉴定。九种衍生物在DPPH测定中显示出浓度依赖性自由基清除活性。还针对由单核细胞增生李斯特菌形成的一组致病性细菌菌株测试了所有化合物(ATCC7644和19115)。金黄色葡萄球菌(ATCC9144),大肠杆菌(ATCC11775和25922),和肠沙门氏菌(ATCC13076)。此外,加合物针对两种无致病性菌株进行了测试,发酵乳杆菌UCO-979C和鼠李糖乳杆菌UCO-25A。总的来说,硫醇衍生的加合物显示抗菌性能,在某些特定情况下,抑制生物膜形成,特别是在单核细胞增生李斯特菌(ATCC7644)中。有趣的是,酚类加合物对所有菌株均无活性,并且不能抑制其生物膜的形成。此外,根据结构,在特定情况下,生物膜的形成得到了强烈的促进。这些发现有助于证明CPC是使用鳄梨果皮作为PACc提取起始材料来分离新半合成分子的强大工具。这些化合物代表了具有抗氧化和抗微生物活性的新的先导分子。
    Polyphenols from agro-food waste represent a valuable source of bioactive molecules that can be recovered to be used for their functional properties. Another option is to use them as starting material to generate molecules with new and better properties through semi-synthesis. A proanthocyanidin-rich (PACs) extract from avocado peels was used to prepare several semi-synthetic derivatives of epicatechin by acid cleavage in the presence of phenol and thiol nucleophiles. The adducts formed by this reaction were successfully purified using one-step centrifugal partition chromatography (CPC) and identified by chromatographic and spectroscopic methods. The nine derivatives showed a concentration-dependent free radical scavenging activity in the DPPH assay. All compounds were also tested against a panel of pathogenic bacterial strains formed by Listeria monocytogenes (ATCC 7644 and 19115), Staphylococcus aureus (ATCC 9144), Escherichia coli (ATCC 11775 and 25922), and Salmonella enterica (ATCC 13076). In addition, adducts were tested against two no-pathogenic strains, Limosilactobacillus fermentum UCO-979C and Lacticaseibacillus rhamnosus UCO-25A. Overall, thiol-derived adducts displayed antimicrobial properties and, in some specific cases, inhibited biofilm formation, particularly in Listeria monocytogenes (ATCC 7644). Interestingly, phenolic adducts were inactive against all the strains and could not inhibit its biofilm formation. Moreover, depending on the structure, in specific cases, biofilm formation was strongly promoted. These findings contribute to demonstrating that CPC is a powerful tool to isolate new semi-synthetic molecules using avocado peels as starting material for PACc extraction. These compounds represent new lead molecules with antioxidant and antimicrobial activity.
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  • 文章类型: Journal Article
    细胞内tau原纤维是阿尔茨海默病神经毒性和氧化应激的来源。目前的药物发现努力集中在具有tau原纤维解聚和抗氧化功能的分子上。然而,最近的研究表明,含有膜结合tau的寡聚物(mTCOs),比tau原纤维更小,更不有序,在阿尔茨海默氏症的早期阶段有神经毒性。Tau原纤维靶向分子是否对mTCOs有效尚不清楚。表没食子儿茶素-3-没食子酸酯(EGCG)的结合,使用机器学习增强的对接和分子动力学模拟研究了CNS-11和BHT-CNS-11对计算机mTCO和实验tau原纤维的影响。EGCG和CNS-11具有tau原纤维解聚功能,而提出的BHT-CNS-11具有潜在的tau原纤维解聚和抗氧化功能,如EGCG。我们的结果表明,所研究的三种分子也可能与mTCOs结合。EGCG与mTCO的预测结合概率随蛋白质聚集体大小而增加。相比之下,CNS-11和BHT-CNS-11与二聚体mTCOs结合的预测概率高于高tau与四聚体mTCOs结合的概率,而非异源tau-胰淀素寡聚体。我们的结果也支持阴离子脂质可以促进分子与mTCO的结合的观点。我们得出结论,tau原纤维解聚和抗氧化分子可能与mTCOs结合,mTCOs也可能是阿尔茨海默病药物设计的有用靶标。
    Intracellular tau fibrils are sources of neurotoxicity and oxidative stress in Alzheimer\'s. Current drug discovery efforts have focused on molecules with tau fibril disaggregation and antioxidation functions. However, recent studies suggest that membrane-bound tau-containing oligomers (mTCOs), smaller and less ordered than tau fibrils, are neurotoxic in the early stage of Alzheimer\'s. Whether tau fibril-targeting molecules are effective against mTCOs is unknown. The binding of epigallocatechin-3-gallate (EGCG), CNS-11, and BHT-CNS-11 to in silico mTCOs and experimental tau fibrils was investigated using machine learning-enhanced docking and molecular dynamics simulations. EGCG and CNS-11 have tau fibril disaggregation functions, while the proposed BHT-CNS-11 has potential tau fibril disaggregation and antioxidation functions like EGCG. Our results suggest that the three molecules studied may also bind to mTCOs. The predicted binding probability of EGCG to mTCOs increases with the protein aggregate size. In contrast, the predicted probability of CNS-11 and BHT-CNS-11 binding to the dimeric mTCOs is higher than binding to the tetrameric mTCOs for the homo tau but not for the hetero tau-amylin oligomers. Our results also support the idea that anionic lipids may promote the binding of molecules to mTCOs. We conclude that tau fibril-disaggregating and antioxidating molecules may bind to mTCOs, and that mTCOs may also be useful targets for Alzheimer\'s drug design.
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  • 文章类型: Journal Article
    在这项研究中,分析了由龙舌兰汁(AS)和刺梨汁(PPJ)组合制成的饮料的营养成分以及生物活性和潜在的健康促进化合物。评估饮料作为抗氧化剂的能力,调节血糖特性,并在体外进行肠道细菌发酵。饮料中存在的主要单糖和低聚糖是半乳糖醛酸(217.74±13.46mg/100mL),鼠李糖(227.00±1.58毫克/100毫升),和果糖(158.16±8.86mg/mL)。确定的主要酚类化合物是原儿茶酸(440.31±3.06mg/100mL)和儿茶素(359.72±7.56mg/100mL)。观察到饮料具有低血糖指数(<40)并且可以抑制消化糖酶。成分的组合还有助于将AS发酵期间的气体产量从56.77cm3降低至15.67cm3。发酵过程中产生的主要SCFA是丁酸盐,醋酸盐,和丙酸,戊酸仅在AS的后期发酵过程中产生。这种饮料富含生物活性化合物,如多酚和膳食纤维,食用时会带来健康益处。
    In this study, a beverage made from a combination of Agave sap (AS) and prickly pear juice (PPJ) was analyzed for its nutrients and bioactive and potentially health-promoting compounds. The beverage was evaluated for its ability to act as an antioxidant, regulate glycemic properties, and undergo gut bacterial fermentation in vitro. The major mono- and oligosaccharides present in the beverage were galacturonic acid (217.74 ± 13.46 mg/100 mL), rhamnose (227.00 ± 1.58 mg/100 mL), and fructose (158.16 ± 8.86 mg/mL). The main phenolic compounds identified were protocatechuic acid (440.31 ± 3.06 mg/100 mL) and catechin (359.72 ± 7.56 mg/100 mL). It was observed that the beverage had a low glycemic index (<40) and could inhibit digestive carbohydrases. The combination of ingredients also helped to reduce gas production during AS fermentation from 56.77 cm3 to 15.67 cm3. The major SCFAs produced during fermentation were butyrate, acetate, and propionate, with valerate being produced only during the late fermentation of the AS. This beverage is rich in bioactive compounds, such as polyphenols and dietary fiber, which will bring health benefits when consumed.
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  • 文章类型: Journal Article
    TRAF6是一种E3泛素连接酶,在细胞信号传导中起着至关重要的作用。已知MMP参与肿瘤的转移,和TRAF6通过与BSG结合诱导MMP-9表达。然而,抑制TRAF6的泛素酶活性而不破坏RING结构域是一个需要进一步研究的挑战。为了解决这个问题,我们进行了基于计算机的药物筛选,以鉴定潜在的TRAF6抑制剂.使用基于抑制剂EGCG的配体-受体复合物药效团,以其抗肿瘤特性而闻名,我们筛选了52,765种海洋化合物。在405分子与TRAF6的分子对接后,选择6种化合物用于进一步分析。通过替换非结合化合物的片段并进行第二次对接,我们确定了两个有希望的分子,CMNPD9212-16和CMNPD12791-8,具有很强的结合活性和良好的药理特性。ADME和毒性预测证实了它们作为TRAF6抑制剂的潜力。分子动力学模拟显示CMNPD12791-8与靶蛋白保持稳定的结构,相当于EGCG。因此,CMNPD12791-8有望作为TRAF6的潜在抑制剂抑制肿瘤生长和转移。
    TRAF6 is an E3 ubiquitin ligase that plays a crucial role in cell signaling. It is known that MMP is involved in tumor metastasis, and TRAF6 induces MMP-9 expression by binding to BSG. However, inhibiting TRAF6\'s ubiquitinase activity without disrupting the RING domain is a challenge that requires further research. To address this, we conducted computer-based drug screening to identify potential TRAF6 inhibitors. Using a ligand-receptor complex pharmacophore based on the inhibitor EGCG, known for its anti-tumor properties, we screened 52,765 marine compounds. After the molecular docking of 405 molecules with TRAF6, six compounds were selected for further analysis. By replacing fragments of non-binding compounds and conducting second docking, we identified two promising molecules, CMNPD9212-16 and CMNPD12791-8, with strong binding activity and favorable pharmacological properties. ADME and toxicity predictions confirmed their potential as TRAF6 inhibitors. Molecular dynamics simulations showed that CMNPD12791-8 maintained a stable structure with the target protein, comparable to EGCG. Therefore, CMNPD12791-8 holds promise as a potential inhibitor of TRAF6 for inhibiting tumor growth and metastasis.
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  • 文章类型: Journal Article
    食物的化学成分很复杂,变量,取决于许多因素。这对营养研究产生了重大影响,因为它从根本上影响了我们充分评估营养素和其他化合物实际摄入量的能力。尽管如此,关于营养素摄入量的准确数据是调查摄入量之间关联和因果关系的关键,健康,和疾病风险,以制定基于证据的饮食指导,从而改善人口健康。这里,我们通过使用三种生物活性物质作为模型来调查食物含量变异性对营养研究的影响来举例说明这一挑战的重要性:Favan-3-ols,(-)-表儿茶素,和硝酸盐。我们的结果表明,旨在解决即使是相同食物的高成分变异性的常见方法通常会阻碍对营养素摄入量的准确评估。这表明,许多使用食物成分数据的营养研究结果可能不可靠,并且具有比通常理解的更大的局限性。因此,导致饮食建议具有显著的fi不能限制和对公共卫生的不可靠影响。因此,当前与营养摄入评估相关的挑战需要通过开发涉及使用营养生物标志物的改良饮食评估方法来解决和缓解.
    关于食物或营养素的健康益处的研究通常不一致。一项研究可能会发现特定食物的健康益处,并可能建议人们增加对这种食物的消费以降低疾病风险。另一项研究可能会发现相反的情况。不一致的研究结果助长了混乱和沮丧,减少对研究的信任。研究设计中的局限性可能会归咎于不一致的发现。例如,许多研究依赖于参与者自我报告他们的食物摄入量和食物营养成分的数据库。但是人们可能无法准确地报告他们的食物摄入量。食物的营养成分各不相同,甚至在相同食物的两个项目之间,例如两个苹果。个人如何代谢食物会进一步影响他们接受的营养。营养生物标志物是测量特定营养素的饮食摄入量的潜在替代方法。生物标志物是身体代谢特定营养素时产生的化合物。因此,测量生物标志物可以为科学家提供更准确和公正的营养摄入量评估。Ottaviani等人。进行了一项研究,以测试使用营养生物标志物与更常规工具估算营养摄入量时的差异。他们分析了一项涉及18,000多名参与者的营养研究的数据。实验使用计算机建模来评估研究结果,使用自我报告的食物摄入量与食物成分数据库信息相结合,或三种生物标志物的测量,估计黄烷-3-醇的摄入量,表儿茶素,和硝酸盐。这些模型表明,自我报告的摄入量和食物数据库信息通常导致不准确的结果,与生物标志物测量结果不一致。测量营养生物标志物提供了更准确和无偏见的营养摄入评估。使用这些测量代替传统的方法来测量营养摄入量可能有助于提高营养研究的可靠性。科学家必须努力识别和确认营养素的生物标志物,以促进这项工作。在研究中使用这些更精确的营养测量可能会导致更一致的结果。这也可能为消费者带来更可靠的推荐。
    The chemical composition of foods is complex, variable, and dependent on many factors. This has a major impact on nutrition research as it foundationally affects our ability to adequately assess the actual intake of nutrients and other compounds. In spite of this, accurate data on nutrient intake are key for investigating the associations and causal relationships between intake, health, and disease risk at the service of developing evidence-based dietary guidance that enables improvements in population health. Here, we exemplify the importance of this challenge by investigating the impact of food content variability on nutrition research using three bioactives as model: flavan-3-ols, (-)-epicatechin, and nitrate. Our results show that common approaches aimed at addressing the high compositional variability of even the same foods impede the accurate assessment of nutrient intake generally. This suggests that the results of many nutrition studies using food composition data are potentially unreliable and carry greater limitations than commonly appreciated, consequently resulting in dietary recommendations with significant limitations and unreliable impact on public health. Thus, current challenges related to nutrient intake assessments need to be addressed and mitigated by the development of improved dietary assessment methods involving the use of nutritional biomarkers.
    Studies about the health benefits of foods or nutrients are often inconsistent. One study may find a health benefit of a particular food and may recommend that people increase their consumption of this food to reduce their disease risk. Yet another study may find the opposite. Inconsistent study results fuel confusion and frustration, and reduce trust in research. Limitations in the studies’ designs are likely to be blamed for the inconsistent findings. For example, many studies rely on participants to self-report their food intake and on databases of the nutritional content of food. But people may not accurately report their food intake. Foods vary in their nutritional content, even between two items of the same food such as two apples. And how individuals metabolize foods can further affect the nutrients they receive. Nutritional biomarkers are a potential alternative to measuring dietary intake of specific nutrients. Biomarkers are compounds the body produces when it metabolizes a specific nutrient. Measuring biomarkers therefore give scientists a more accurate and unbiased assessment of nutrient intake. Ottaviani et al. conducted a study to test the differences when estimating nutrient intake using nutritional biomarkers compared with more conventional tools. They analyzed data from a nutrition study that involved over 18,000 participants. The experiments used computer modelling to assess study results using self-reported food intake in combination with food composition database information, or measures of three biomarkers estimating the intake of flavan-3-ols, epicatechin, and nitrates. The models showed that self-reported intake and food database information often led to inaccurate results that did not align well with biomarker measurements. Measuring nutritional biomarkers provides a more accurate and unbiased assessment of nutritional intake. Using these measurements instead of traditional methods for measuring nutrient intake may help increase the reliability of nutrition research. Scientists must work to identify and confirm biomarkers of nutrients to facilitate this work. Using these more precise nutrient measurements in studies may result in more consistent results. It may also lead to more trustworthy recommendations for consumers.
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  • 文章类型: Journal Article
    作为一种非破坏性的,快,和具有成本效益的技术,近红外(NIR)光谱技术已被广泛应用于茶叶中生物活性成分的测定。然而,由于红茶中各种儿茶素的化学结构相似,红茶的近红外光谱在某些波段严重重叠,造成非线性关系,降低分析精度。此外,近红外光谱波长的数量远远大于建模样品的数量,小样本学习问题相当典型。这些问题使得使用NIRS同时测定红茶儿茶素具有挑战性。为解决上述问题,本研究创新性地提出了一种基于特征区间组合灵敏度分割的波长选择算法(FIC-SS)。该算法提取了粗粒度和细粒度水平的波长,在特征波长提取中实现更高的精度和稳定性。在此基础上,这项研究建立了四种基于极限学习机(ELM)的儿茶素同步预测模型,利用其强大的非线性学习能力和简单的模型结构,实现对儿茶素的同步准确预测。实验结果表明,对于全光谱,ELM模型对表儿茶素(EC)的预测性能优于偏最小二乘模型,表儿茶素没食子酸酯(ECG),表没食子儿茶素(EGC),和表没食子儿茶素没食子酸酯(EGCG)。对于特征波长,我们提出的FIC-SS-ELM模型比基于其他波长选择算法的ELM模型具有更高的预测性能;它可以同时准确地预测EC的含量(Rp2=0.91,RMSEP=0.019),心电图(Rp2=0.96,RMSEP=0.11),EGC(Rp2=0.97,RMSEP=0.15),红茶中的EGCG(Rp2=0.97,RMSEP=0.35)。本研究结果为红茶中生物活性成分的定量测定提供了一种新方法。
    As a non-destructive, fast, and cost-effective technique, near-infrared (NIR) spectroscopy has been widely used to determine the content of bioactive components in tea. However, due to the similar chemical structures of various catechins in black tea, the NIR spectra of black tea severely overlap in certain bands, causing nonlinear relationships and reducing analytical accuracy. In addition, the number of NIR spectral wavelengths is much larger than that of the modeled samples, and the small-sample learning problem is rather typical. These issues make the use of NIRS to simultaneously determine black tea catechins challenging. To address the above problems, this study innovatively proposed a wavelength selection algorithm based on feature interval combination sensitivity segmentation (FIC-SS). This algorithm extracts wavelengths at both coarse-grained and fine-grained levels, achieving higher accuracy and stability in feature wavelength extraction. On this basis, the study built four simultaneous prediction models for catechins based on extreme learning machines (ELMs), utilizing their powerful nonlinear learning ability and simple model structure to achieve simultaneous and accurate prediction of catechins. The experimental results showed that for the full spectrum, the ELM model has better prediction performance than the partial least squares model for epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), and epigallocatechin gallate (EGCG). For the feature wavelengths, our proposed FIC-SS-ELM model enjoys higher prediction performance than ELM models based on other wavelength selection algorithms; it can simultaneously and accurately predict the content of EC (Rp2 = 0.91, RMSEP = 0.019), ECG (Rp2 = 0.96, RMSEP = 0.11), EGC (Rp2 = 0.97, RMSEP = 0.15), and EGCG (Rp2 = 0.97, RMSEP = 0.35) in black tea. The results of this study provide a new method for the quantitative determination of the bioactive components of black tea.
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  • 文章类型: Journal Article
    表没食子儿茶素没食子酸酯(EGCG),绿茶中的主要儿茶素,表现出不同的治疗特性。然而,其临床疗效受到稳定性差和生物利用度低的阻碍。这项研究研究了以乳清分离蛋白(WPI)和酪蛋白酸钠(NaCas)为载体稳定的固体颗粒水包油(S/O/W)乳液,以提高EGCG的生物利用度和肠道吸收。分子对接揭示了EGCG与这些大分子之间的结合相互作用。WPI和NaCas稳定的乳液表现出高包封效率(>80%),并且在模拟胃肠消化后与游离EGCG相比,EGCG的生物可及性显著提高64%。值得注意的是,NaCas乳液促进了EGCG跨Caco-2单层的更高的肠道通透性,归因于酪蛋白和EGCG之间强烈的分子间相互作用。此外,乳液通过抑制细胞内活性氧的产生来保护Caco-2细胞免受氧化应激。这些发现证明了WPI和NaCas稳定的乳液作为有效的递送系统来提高生物利用度的潜力。稳定性,和EGCG等多酚的生物活性,使其在功能性食品和营养食品中的应用成为可能。
    Epigallocatechin gallate (EGCG), the principal catechin in green tea, exhibits diverse therapeutic properties. However, its clinical efficacy is hindered by poor stability and low bioavailability. This study investigated solid particle-in-oil-in-water (S/O/W) emulsions stabilized by whey protein isolate (WPI) and sodium caseinate (NaCas) as carriers to enhance the bioavailability and intestinal absorption of EGCG. Molecular docking revealed binding interactions between EGCG and these macromolecules. The WPI- and NaCas-stabilized emulsions exhibited high encapsulation efficiencies (>80%) and significantly enhanced the bioaccessibility of EGCG by 64% compared to free EGCG after simulated gastrointestinal digestion. Notably, the NaCas emulsion facilitated higher intestinal permeability of EGCG across Caco-2 monolayers, attributed to the strong intermolecular interactions between caseins and EGCG. Furthermore, the emulsions protected Caco-2 cells against oxidative stress by suppressing intracellular reactive oxygen species generation. These findings demonstrate the potential of WPI- and NaCas-stabilized emulsions as effective delivery systems to improve the bioavailability, stability, and bioactivity of polyphenols like EGCG, enabling their applications in functional foods and nutraceuticals.
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