普洱茶调控肥胖作用研究进展

随着国民经济的高速发展,人民生活水平显著提升,然而世界范围内肥胖人群也与日俱增。普洱茶中含有茶多酚、没食子酸、茶多糖、茶褐素、咖啡碱等多种生物活性物质,可通过抑制脂肪细胞增殖分化、调节脂肪代谢、抗氧化和抗炎症、调节肠道菌群、调控相关基因和蛋白质的表达等多种不同途径调控肥胖。本文综述了近年来普洱茶调控肥胖功能及其作用机制的研究进展,为后续相关研究提供参考。     

茶多糖提取纯化、结构活性及应用研究进展

我国茶叶产量世界第一,茶资源十分丰富。茶多糖作为从茶叶、茶花和茶籽中提取出来的一种复合多糖,因具有抗糖尿病、抗氧化、抗肿瘤、增强免疫和调节肠道菌群等多种生物活性引起极大关注,并被广泛应用于保健品、化妆品和医药等领域。文章对茶多糖的提取纯化、化学结构、功能活性及产业化应用进行综述,以加强对茶多糖的认知,推动茶叶健康产业发展。     

茶多酚抗肥胖作用研究进展

随着肥胖率持续增高,寻求天然抗肥胖药物成为人们持续关注的热点。茶多酚是茶叶中主要活性成分,大量研究表明其在抗肥胖方面具有良好的作用效果,可通过调节酶活性,抑制脂肪的积累、促进脂肪氧化,刺激机体能量的消耗、调控信号通路,减轻肥胖炎症、调节肠道菌群紊乱,促进优势菌增长等途径有效预防和控制肥胖。本文综述了近年来茶多酚调控肥胖的药理活性及作用机理,从而为开发天然减肥功能食品和药物提供有益参考。     

黄茶功能性成分与健康功效研究进展

黄茶是我国六大茶类之一。近年来,黄茶以其独特的风味特点和显著的保健功效日益受到消费者的喜爱。文章对黄茶中的茶多酚、生物碱、氨基酸和茶多糖等主要功能性成分,以及黄茶降糖降脂、调节肠道微生物组成、抗炎抗菌、抗癌和抗氧化等健康功效进行综述,旨在为黄茶产业高质量发展提供理论参考。     

茶多糖的研究进展

糖类是自然界最多的有机化合物,多糖及糖复合物分布广泛,功能多种多样,它们参与了细胞各种生命活动的调节。茶多糖(TPS)能降血糖、防治糖尿病,还具有降血脂、抗动脉粥样硬化、降血压、抗凝血、抗血栓、防治心血管疾病等作用。在中国和日本民间有常饮用粗老茶治疗糖尿病的经验。一般随茶叶原料的老化,茶多糖含量增加,乌龙茶中茶多糖含量为2.63%±0.27%,约是红茶的31倍和绿茶的17倍。红茶一级的茶多糖含量为0.40%±0.10%,到了六级可达0.85%±0.10%。绿茶一级的茶多糖含量为0.81%±0.11%,六级达到1.41%±0.06%。本文对茶多糖的提取、分离提纯…     

几种茶多糖降血糖活性的研究

研究和对比白茶多糖（White tea polysaccharide,WTP）、绿茶多糖（Green tea polysaccharide,GTP）和红茶多糖（Black tea polysaccharide,BTP）的成分、降血糖效果及机理。分别选取寿眉、龙井、白琳工夫作为白茶、绿茶和红茶的代表,测定分析茶多糖提取物的成分和分子量。以链脲佐菌素诱导小鼠糖尿病模型,二甲双胍作为阳性对照,研究茶多糖降血糖效果,qPCR测定小鼠肝脏中相关基因表达水平。结果表明,所选白茶、绿茶和红茶多糖的绝对重均分子量分别为18 180、19 470、8 745 Da。所选茶多糖提取物均具有降血糖功效,白茶、绿茶和红茶多糖干预组小鼠的血糖下降率分别为53.2%、52.8%及61.6%。茶多糖均可改善小鼠葡萄糖耐量,调节糖代谢相关基因表达,并且存在一定差异。     

茶多糖研究的新进展

茶多糖是茶叶中一种重要的功能性大分子。本文从茶多糖的分离纯化工艺的研究、茶多糖结构与结构修饰的研究、茶多糖生物学活性的研究和茶多糖产品的开发利用这四个方面综述了2006年以来茶多糖研究的新成果。分析了茶多糖研究现状与发展新趋势。     

茶多糖的化学修饰及体外抗凝血作用研究

采用DEAE-52纤维素柱层析的方法,分离纯化乌龙茶中的多糖成分;选用硫酸化、乙酰化和羧甲基化分别对纯化后的茶多糖进行化学修饰,研究了其修饰前后的体外抗凝血作用。结果表示:茶多糖具有抗凝血作用,能显著延长人体血浆的APTT值,而对TT和PT值无明显影响。茶多糖经柱层析后分离出四个多糖组分,其中组分Ⅱ为茶多糖总量的57.36%,抗凝血活性也相对较强。茶多糖组分Ⅱ经硫酸化、乙酰化和羧甲基化修饰后,抗凝血活性进一步增强,化学修饰试剂与多糖的比例以及修饰反应时间在一定的范围内,影响茶多糖分子结构的变化程度,相应改变抗凝血活性。     

太极柔力球结合普洱茶对肥胖大学生的干预影响

普洱茶具有治疗肥胖症的功用,它在日常生活中对人们的健康调节有着重要作用。大学生作为一种特殊的群体,肥胖现象越来越常见,其中一种干预肥胖的措施就是采用太极柔力球与普洱茶相结合,引导学生通过运动与饮茶来实现减肥的目的。从当前太极柔力球结合普洱茶在大学生群体中的应用现状来看,这种有氧运动融合普洱茶的方式对大学生减肥效果是有明显作用的,具有很高的采用价值。     

茶多糖的组分及理化性质

粗老茶中含有较高能治疗糖尿病的茶多糖成分。用紫外、红外和气相色谱等方法对茶多糖分析结果表明，它是由糖类、蛋白质、果胶和灰分等物质组成；其多糖部分为阿拉伯糖、木糖、岩藻糖、葡萄糖和半乳糖等，各单糖的组成比例为５．５２：２．２１：６．０８：４４．２０：４１．９９。多糖的分子量约１０７０００。茶多糖的热稳定性较差，高温或过酸和偏碱均会使其中的多糖部分降解。它在沸水中溶解性能较好，但不溶于高浓度的有机溶剂。文中还对粗老茶中的降血糖成分、茶多糖组分和分子量上的差异原因，以及茶多糖中灰分含量高的原因进行了讨论。     

绿茶茶汤对肥胖相关肠道菌群的影响

近年来,饮茶调节肠道微生态的效果受到广泛关注。本研究通过将绿茶茶汤与志愿者新鲜粪样混合培养,使用荧光原位杂交技术考察不同发酵时间点(0、6、12、24 h)绿茶茶汤对与肥胖密切相关的肠道菌群(包括总菌、拟杆菌门微生物和厚壁菌门微生物)的影响,从而评估绿茶茶汤调节肠道微生态作用的效果。实验结果表明,绿茶茶汤在体外粪样混合培养体系中发酵24 h时,对于肠道中总菌、拟杆菌门微生物以及厚壁菌门微生物的数量减少有抑制效果(P0.05),并可以改善肠道中拟杆菌门与厚壁菌门的相对丰度,降低厚壁菌门与拟杆菌门比例(F/B),这为饮茶对改善肠道健康、减肥降脂作用提供了一定的理论参考。     

Inhibition of Intestinal Lipid Absorption by Cyanobacterial Strains in Zebrafish Larvae

Obesity is a complex metabolic disease, which is increasing worldwide. The reduction of dietary lipid intake is considered an interesting pathway to reduce fat absorption and to affect the chronic energy imbalance. In this study, zebrafish larvae were used to analyze effects of cyanobacteria on intestinal lipid absorption in vivo. In total, 263 fractions of a cyanobacterial library were screened for PED6 activity, a fluorescent reporter of intestinal lipases, and 11 fractions reduced PED6 activity > 30%. Toxicity was not observed for those fractions, considering mortality, malformations or digestive physiology (protease inhibition). Intestinal long-chain fatty acid uptake (C16) was reduced, but not short-chain fatty acid uptake (C5). Alteration of lipid classes by high-performance thin-layer chromatography (HPTLC) or lipid processing by fluorescent HPTLC was analyzed, and 2 fractions significantly reduced the whole-body triglyceride level. Bioactivity-guided feature-based molecular networking of LC-MS/MS data identified 14 significant bioactive mass peaks (p < 0.01, correlation > 0.95), which consisted of 3 known putative and 11 unknown compounds. All putatively identified compounds were known to be involved in lipid metabolism and obesity. Summarizing, some cyanobacterial strains repressed intestinal lipid absorption without any signs of toxicity and could be developed in the future as nutraceuticals to combat obesity.     

茶多酚对肠道微生物的调节作用研究进展

代谢综合征是高血压、血糖异常、血脂紊乱和肥胖症等疾病在人体内集结的一组复杂的代谢紊乱症候群。茶多酚是茶叶中的特征次生代谢产物之一,最新研究表明,茶多酚可以通过对肠道菌群的干预,改善肠道菌群紊乱,调节宿主-肠道菌群的共代谢过程,进而达到改善代谢综合征的目的。本文系统总结了茶多酚的吸收与代谢,以及茶多酚在体外发酵模型、动物试验和临床试验中对肠道菌群的影响,阐述了茶多酚-微生物群-宿主三者之间的内在作用机制,有助于以肠道菌群理论为基础探讨茶多酚对人体健康的作用,并为茶多酚的功能性产品开发提供理论依据。     

普洱茶对非酒精性脂肪肝大鼠肠道脂肪吸收及粘膜屏障的干预研究

研究了普洱茶调控非酒精性脂肪肝大鼠肠道对长链脂肪酸的吸收,并探讨了其可能机制。将36只SD大鼠随机分成正常对照组、脂肪肝模型组和普洱茶干预组,每组12只。实验第8周末处死所有大鼠,测定大鼠体质量、肝指数及血清血脂水平;采用定量PCR测定大鼠肠道黏膜脂质吸收相关蛋白细胞分化抗原36(Cluster of differentiation 36,CD36)、紧密连接相关蛋白如闭锁蛋白(Occludin)、紧密连接蛋白(Zonula occludens 1,ZO-1)和肿瘤坏死因子α(Tumor necrosis factor-α,TNF-α)基因表达水平。研究结果表明,与模型组相比,普洱茶组大鼠体质量和血清LDL-C水平分别下降了16.12%和42.59%;此外,普洱茶组大鼠小肠组织CD36、TNF-α表达水平明显降低,而Occludin、ZO-1表达水平明显升高。研究发现,普洱茶对NAFLD大鼠肠道长链脂肪酸吸收及肠道紧密连接蛋白有一定程度的调控作用,尤其是对NAFLD早期发生发展中游离脂肪酸过度沉积的"第一次打击"有防治价值。     

Advances in Studies on the Pharmacological Activities of Fucoxanthin

Fucoxanthin is a natural carotenoid derived mostly from many species of marine brown algae. It is characterized by small molecular weight, is chemically active, can be easily oxidized, and has diverse biological activities, thus protecting cell components from ROS. Fucoxanthin inhibits the proliferation of a variety of cancer cells, promotes weight loss, acts as an antioxidant and anti-inflammatory agent, interacts with the intestinal flora to protect intestinal health, prevents organ fibrosis, and exerts a multitude of other beneficial effects. Thus, fucoxanthin has a wide range of applications and broad prospects. This review focuses primarily on the latest progress in research on its pharmacological activity and underlying mechanisms.     

Implication of Echinochrome A in the Plasticity and Damage of Intestinal Epithelium

The diverse therapeutic feasibility of the sea urchin-derived naphthoquinone pigment, Echinochrome A (Ech A), has been studied. Simple and noninvasive administration routes should be explored, to obtain the feasibility. Although the therapeutic potential has been proven through several preclinical studies, the biosafety of orally administered Ech A and its direct influence on intestinal cells have not been evaluated. To estimate the bioavailability of Ech A as an oral administration drug, small intestinal and colonic epithelial organoids were developed from mice and humans. The morphology and cellular composition of intestinal organoids were evaluated after Ech A treatment. Ech A treatment significantly increased the expression of LGR5 (~2.38-fold change, p = 0.009) and MUC2 (~1.85-fold change, p = 0.08). Notably, in the presence of oxidative stress, Ech A attenuated oxidative stress up to 1.8-fold (p = 0.04), with a restored gene expression of LGR5 (~4.11-fold change, p = 0.0004), as well as an increased expression of Ly6a (~3.51-fold change, p = 0.005) and CLU (~2.5-fold change, p = 0.01), markers of revival stem cells. In conclusion, Ech A is harmless to intestinal tissues; rather, it promotes the maintenance and regeneration of the intestinal epithelium, suggesting possible beneficial effects on the intestine when used as an oral medication.     

大豆蛋白调节血脂的机理研究

随着对大豆制品的健康作用的认识,西方国家对大豆消耗不断增加.流行病学调查、人群营养干预试验和动物试验都表明大豆蛋白可降低血清总胆固醇、低密度脂蛋白胆同醇、甘油三酯浓度和肝细胞胆固醇和甘油三酯浓度,该文综述了大豆蛋白调理血脂的可能机制.     

High Molecular Weight Fucoidan Restores Intestinal Integrity by Regulating Inflammation and Tight Junction Loss Induced by Methylglyoxal-Derived Hydroimidazolone-1

Fucoidan from brown seaweeds has several biological effects, including preserving intestinal integrity. To investigate the intestinal protective properties of high molecular weight fucoidan (HMWF) from Undaria pinnatifida on intestinal integrity dysfunction caused by methylglyoxal-derived hydroimidazolone-1 (MG-H1), one of the dietary advanced-glycation end products (dAGEs) in the human-colon carcinoma-cell line (Caco-2) cells and ICR mice. According to research, dAGEs may damage the intestinal barrier by increasing gut permeability. The findings of the study showed that HMWF + MG-H1 treatment reduced by 16.8% the amount of reactive oxygen species generated by MG-H1 treatment alone. Furthermore, HMWF + MGH-1 treatment reduced MG-H1-induced monolayer integrity disruption, as measured by alterations in transepithelial electrical resistance (135% vs. 75.5%) and fluorescein isothiocyanate incorporation (1.40 × 10⁻⁶ cm/s vs. 3.80 cm/s). HMWF treatment prevented the MG-H1-induced expression of tight junction markers, including zonula occludens-1, occludin, and claudin-1 in Caco-2 cells and mouse colon tissues at the mRNA and protein level. Also, in Caco-2 and MG-H1-treated mice, HMWF plays an important role in preventing receptor for AGEs (RAGE)-mediated intestinal damage. In addition, HMWF inhibited the nuclear factor kappa B activation and its target genes leading to intestinal inflammation. These findings suggest that HMWF with price competitiveness could play an important role in preventing AGEs-induced intestinal barrier dysfunction.     

Insights from in vitro exploration of factors influencing iron,zinc and provitamin A carotenoid bioaccessibility and intestinal absorption from cereals

Developments in genetics, agronomics and processing has positioned staple cereals as important sources of iron, zinc and provitamin A (pVA) carotenoids for nutritionally vulnerable populations. Significant effort has been placed on understanding the bioavailability of these micronutrients from cereal foods, including the exploration of underlying mechanisms by which their bioavailability can be modified. While micronutrient bioavailability is preferably assessed in clinical trials, relevant in vitro digestion and intestinal cell culture models have been applied to study effects of genetic, agronomic, post-harvest and food processing on micronutrient bioavailability. This review (1) critically assesses the application of in vitro models in the exploration of mechanisms associated with iron, zinc and provitamin A carotenoid bioaccessibility and intestinal absorption from cereal foods, and (2) identifies remaining gaps in order to frame future strategies to improve the nutritional impact of cereal foods.     

The Role of Chitosan Oligosaccharide in Metabolic Syndrome: A Review of Possible Mechanisms

Metabolic syndrome, a cluster of metabolic disorders including central obesity, insulin resistance, hyperglycemia, dyslipidemia, and hypertension, has become a major public health problem worldwide. It is of great significance to develop natural products to prevent and treat metabolic syndrome. Chitosan oligosaccharide (COS) is an oligomer of chitosan prepared by the deacetylation of chitin, which is the second most abundant polymer in nature. In recent years, COS has received widespread attention due to its various biological activities. The present review will summarize the evidence from both in vitro and in vivo studies of the beneficial effects of COS on obesity, dyslipidemia, diabetes mellitus, hyperglycemia, and hypertension, and focus attention on possible mechanisms of the prevention and treatment of metabolic syndrome by COS.