茶叶水浸液对肠道致病菌抑菌作用的研究

目的 了解普通绿茶、红茶、菊花茶、乌龙茶、普洱茶水浸液对肠道致病菌的抑菌作用.方法 采用平板孔穴法进行茶叶水浸液抑制副溶血性弧菌、大肠埃希菌、沙门菌属、志贸菌属效果的研究.结果 普通绿茶、红茶、菊花茶、乌龙茶、普洱茶初次水浸液对副溶血性弧菌有抑菌作用;普通绿茶、普洱茶初次水浸液对大肠埃希菌有抑制作用;普通绿茶、红茶、乌龙茶、普洱茶初次水浸液对沙门菌属、志贺菌属有抑菌作用;其中以普通绿茶和普洱茶对副溶血性弧菌的抑菌效果最好,2.5 mg/ml初次水浸液抑菌环直径分别为10.6 mm和12.3 mm.结论 茶叶对肠道致病菌有抑菌作用.     

茶叶对N-亚硝基化合物体外形成的影响

本文研究了在体外模拟胃液条件下,17种茶叶对N—亚硝基脯氨酸合成的影响。结果指出:当茶叶水提取液加入量为低水平时,对合成有催化作用;加入量为高水平时则具有阻断作用。其阻断能力,以乌龙茶和绿茶最好,紧压茶次之,红茶、花茶较差。     

怎样冲泡不同种类的茶叶

<正>想要喝一杯上等的好茶,除了应保证茶叶的质量外,还要掌握泡茶的要点。平日里,人们经常饮用的茶叶多为绿茶、红茶、乌龙茶和黑茶,那么这些茶叶应如何冲泡呢?1.绿茶绿茶之所以具有抗氧化、清除自由基、抗衰老、抗病毒等功效,主要是因为其中含有大量的     

不同茶叶对D-半乳糖衰老小鼠抗氧化作用比较

目的比较4种不同发酵类型茶叶对D-半乳糖衰老小鼠的抗氧化作用。方法将小鼠随机分为7组(对照组、模型组、绿茶组、乌龙茶组、红茶组、黑茶组和阳性对照组),除对照组外,其余6组皮下注射D-半乳糖建立氧化损伤动物模型,在造模同时各茶叶组和阳性对照组分别灌胃茶叶水(2 g/kg)和维生素C(10 mg/kg),30 d后处死小鼠测定脏器指数,血清、肝脏和脑组织SOD、CAT活力和T-AOC。结果绿茶能提高D-半乳糖模型小鼠肝脏、脑组织、脾脏和胸腺脏器指数,差异有统计学意义(P<0.05);绿茶组血清SOD、CAT活力和T-AOC分别为(139.18±8.19)、(6.03±0.56)和(17.67±0.71)U/mL,与模型组比较,明显升高,差异有统计学意义(P<0.01);绿茶、红茶和黑茶对肝脏和脑组织SOD、CAT活力和T-AOC均有提高作用(P<0.05),且绿茶效果强于红茶和黑茶。结论不同发酵类型茶叶对D-半乳糖衰老小鼠均具有抗氧化作用,其中绿茶在4种发酵类型茶叶中抗氧化能力最强。     

茶叶抗癌效果座次排定

现已证实.茶具有抗多种致癌物质诱导的突变,抑制癌细胞DNA合成.影响酶活性和直接杀伤癌细胞等作用.最近,湖北医科大学茶与健康研究室排定了不同茶叶抗癌效果的顺序.未经发酵的绿茶抗癌作用最强,半发酵的乌龙茶次之,全发酵的红茶再次之.不同产地、不同茶树品种、不同加工方法的茶叶,其抗癌作用有异.茶叶的抗     

红茶保健作用不如绿茶吗

红茶较为平缓温和,有暖胃作用。与绿茶相比．晚间更适合饮用红茶。红茶还有降血脂、预防感冒的作用。所有茶叶包括红茶都含有丰富的黄酮类物质,可减少妇女患骨质疏松症的危险。     

把乌龙茶喝“到位”

<正>乌龙茶也称青茶,制茶的工艺大致步骤可分为:晒青、晾青、摇青、揉捻、干燥和拣梗,是介于绿茶(不发酵)和红茶(完全发酵)之间的一类半发酵茶叶。因此,它具有绿茶清香的气味和红茶甘甜的口感,并且巧妙地抑制了红茶之涩和绿茶之苦。     

茶叶抗氧化功能的研究

方法：１０８只１２月龄ＳＤ大鼠用（ｇ／３００ｂｗ．ｄ）０．１５、０．３０、０．６０茶叶和（％）０．６、１．２、２．４浓度茶汤每日每只２５ｍｌ喂养２个月。结果：茶叶和茶汤均能显著提高老龄大鼠过氧化物歧化酶（ＳＯＤ）活力（Ｐ＜０．０１），平均提高红茶为１１７．００％，绿茶为９０．７９％；均能降低大鼠肝丙二醛（ＭＤＡ）的含量，平均降低红茶为３４．６２％（Ｐ＜０．０１），绿茶为２５．３５％（Ｐ＜０．０５）。结论：茶叶具有显著的生物抗氧化作用，且红茶的抗氧化效果比绿茶显著，茶叶的生物抗氧化机制除茶多酚类物质起作用外，可能还有其它重要的机制     

绿茶、乌龙茶、红茶的茶多糖组成、抗氧化及降血糖作用研究

目的:比较绿茶、乌龙茶、红茶的茶多糖(TPS)含量、组成、体外清除自由基以及降血糖效果。方法:选择湖北福鼎大白茶、福建水仙以及云南大叶种鲜叶,都制成绿茶、乌龙茶和红茶,提取TPS,并测定其得率,分析TPS中的中性糖、糖醛酸、蛋白质含量,观察体外清除-2O和·OH的作用以及对四氧嘧啶诱导的糖尿病小鼠的降血糖效果。结果:1. TPS得率、中性糖、糖醛酸、蛋白质含量高低依次为绿茶>乌龙茶>红茶,体外清除 -2O 和·OH 的能力大小依次为乌龙茶>绿茶>红茶。2. 在所设定的低、中、高剂量(100 mg·kg-1·d-1、300 mg·kg-1·d-1、600 mg·kg-1·d-1)下,各种茶叶TPS对DM小鼠都有显著或极显著的降血糖效果,其中在低、中等剂量下,乌龙茶、红茶TPS的降低血糖作用明显优于绿茶TPS,但在高剂量下差异不明显。3. 不同产地、品种和茶类的TPS得率、中性糖、糖醛酸、蛋白质含量高低、体外清除-2O和·OH 能力,对DM小鼠降血糖效果均不相同,其中以湖北产茶叶TPS降血糖效果最好,其次是福建茶叶,再次是云南茶叶。结论:不同产地、品种、加工工艺对茶叶的茶多糖含量、组成、体外清除自由基以及降血糖效果都有显著性影响。     

波利特、达克普隆和Nexium对幽门螺杆菌的体外抑菌效果比较

目的：观察、比较质子泵抑制剂(PPI)波利特(雷贝拉唑肠溶衣片)、达克普隆(兰索拉唑胶囊)和Nexium对幽门螺杆菌(Hp)的抑制作用，初步解释近期临床流行病学资料所显示的不同PPI用于Hp根除治疗所表现的明显效果差异现象。方法：使用Hp国际标准株NCTC11637、NCTC11639和国内分离菌株CAPMN62，应用平板掺入法测定三种PPI对Hp的体外抑菌作用。结果：波利特在体外对Hp具有明显的抑制作用(MIC99为2．25mg／L)，其次为达克普隆(MIC99为42.5mg／L)，而Nexium抑菌作用不明显(MIC99为360mg／L)。结论：不同PPI对Hp的直接抑菌作用存在明显差异，其作用除本身化学结构的差异因素外，制剂中的其他复合成分的影响也不容忽视；亟待对体外抑菌效果与用于Hp感染治疗效果的相关性进行分析，以便更好地指导临床用药和相关幽门螺杆菌病的防治。     

Crude ethanolic extracts of Garcinia kola seeds Heckel (Guttiferae) prolong the lag phase of Helicobacter pylori: inhibitory and bactericidal potential

Problems associated with current treatment regimens have generated a considerable interest in alternative approaches for the eradication of Helicobacter pylori infections using phytochemical compounds. In an attempt to identify potential sources of such compounds, the antimicrobial activity of five solvent extracts of Garcinia kola seeds were investigated against 30 clinical strains of H. pylori and a standard control strain, NCTC 11638, using standard microbiological techniques. Metronidazole and amoxicillin were included in these experiments as positive control antibiotics. All the extracts tested exhibited anti-H. pylori activity with zone diameters of inhibition between 0 and 25 mm. The ethanol extract demonstrated considerable anti-H. pylori activity with a percentage susceptibility of 53.3% and minimum inhibitory concentration for 50% susceptibility (MIC??) values ranging from 0.63 to 5.0 mg/mL. Ranges of MIC?? values for amoxicillin and metronidazole were 0.01-0.63 mg/mL and 0.04-5.0 mg/mL, respectively. The inhibitory activity of the ethanol extract was similar to that of metronidazole (P?>?.05) as opposed to amoxicillin (P?相似文献   

Inhibitory and bactericidal potential of crude acetone extracts of Combretum molle (Combretaceae) on drug-resistant strains of Helicobacter pylori

Infection with Helicobacter pylori is strongly associated with a number of gastroduodenal pathologies. Antimicrobial resistance to commonly-used drugs has generated a considerable interest in the search for novel therapeutic compounds from medicinal plants. As an ongoing effort of this search, the susceptibility of 32 clinical strains of H. pylori and a reference strain-NCTC 11,638-was evaluated against five solvent extracts of Combretum molle, a plant widely used for the treatment of gastric ulcers and other stomach-related morbidities in South Africa. The extracts were screened for activity by the agar-well diffusion method, and the most active one of them was tested against the same strains by micro-broth dilution and time kill assays. Metronidazole and amoxicillin were included in these experiments as positive control antibiotics. The solvent extracts all demonstrated anti-H. pylori activity with zone diameters of inhibition between 0 and 38 mm. The most potent anti-H. pylori activity was demonstrated by the acetone extract, to which 87.5% of the clinical strains were susceptible. The minimum inhibitory concentration (MIC90) values for this extract ranged from 1.25 to 5.0 mg/mL while those for amoxicillin and metronidazole ranged from 0.001 to 0.94 mg/mL and from 0.004 to 5.0 mg/mL respectively. The acetone extract was highly bactericidal at a concentration of 2.5 and 5.0 mg/mL, with complete elimination of the test organisms in 24 hours. Its inhibitory activity was better than that of metronidazole (p<0.05) as opposed to amoxicillin (p<0.05). The results demonstrate that C. molle may contain therapeutically-useful compounds against H. pylori, which are mostly concentrated in the acetone extract.     

Antimicrobial activity of Northwestern Mexican plants against Helicobacter pylori

Helicobacter pylori is the major etiologic agent of such gastric disorders as chronic active gastritis and gastric carcinoma. Over the past few years, the appearance of antibiotic-resistant bacteria has led to the development of better treatments, such as the use of natural products. This study evaluated the anti-H. pylori activity of 17 Mexican plants used mainly in the northwestern part of Mexico (Sonora) for the empirical treatment of gastrointestinal disorders. The anti-H. pylori activity of methanolic extracts of the plants was determined by using the broth microdilution method. The 50% minimum inhibitory concentrations ranged from less than 200 to 400 μg/mL for Castella tortuosa, Amphipterygium adstringens, Ibervillea sonorae, Pscalium decompositum, Krameria erecta, Selaginella lepidophylla, Pimpinella anisum, Marrubium vulgare, Ambrosia confertiflora, and Couterea latiflora and were greater than 800?μg/mL for Byophyllum pinnatum, Tecoma stans linnaeus, Kohleria deppena, Jatropha cuneata, Chenopodium ambrosoides, and Taxodium macronatum. Only Equisetum gigantum showed no activity against H. pylori. This study suggests the important role that these plants may have in the treatment of gastrointestinal disorders caused by H. pylori. The findings set the groundwork for further characterization and elucidation of the active compounds responsible for such activity.     

Inhibitory potential of tea polyphenolics and influence of extraction time against Helicobacter pylori and lack of inhibition of beneficial lactic acid bacteria

Tea polyphenolics such as catechins are known to have the potential to inhibit many bacterial pathogens. Helicobacter pylori has been identified as an etiologic agent in the development of gastric ulcer, peptic ulcer, gastritis, and many other stomach-related diseases. In this study, we investigated the effect of 9 tea extracts--3 different brands representing 4 different processed types (white, green, oolong, and black)--on the inhibition of H. pylori. Extraction times of 2 and 5 minutes were compared. Most 5-minute extracts showed H. pylori inhibition, whereas 2-minute extracts only of Choice darjeeling black and Tazo white showed inhibition. No recovery was observed after the addition of 0.5 and 5 mM proline, indicating that tea polyphenols do not inhibit H. pylori by inhibition of proline oxidation via proline dehydrogenase. Extracts that showed inhibition were further evaluated for their effect on beneficial lactic acid bacteria. None of the samples showed inhibition, suggesting that tea might be able to inhibit H. pylori without affecting the beneficial lactic acid bacteria. High-performance liquid chromatography indicated the presence of gallic acid, quercetin, caffeine, and tea catechins (including catechin, epicatechin, and epigallocatechin) in all the tea samples. Our study indicates that tea can be potentially used as a low-cost dietary support to combat H. pylori-linked gastric diseases without affecting the beneficial intestinal bacteria.     

Effective prevention and treatment of Helicobacter pylori infection using a combination of catechins and sialic acid in AGS cells and BALB/c mice

The increasing emergence of Helicobacter pylori strains resistant to antibiotics may cause unsuccessful treatment. An alternative agent or mixture with anti-H. pylori effect is urgently required to reduce H. pylori infection. We explored the preventive and therapeutic potential of a combination of catechins and sialic acid on H. pylori-infected human gastric cells in vitro and in mice in vivo. We evaluated the anti-H. pylori activity of catechins and/or sialic acid using the agar dilution and checkerboard methods. The effect of catechins and/or sialic acid on H. pylori infection-induced oxidative stress and apoptosis/autophagy in cell culture was explored using an ultrasensitive chemiluminescence analyzer, immunocytochemistry, and Western blotting. Specific pathogen-free BALB/c mice were divided into uninfected control, infected control, pretreated, and post-treated groups. The effects of catechins/sialic acid were determined by histology and immunocytochemistry. The combination of catechins and sialic acid showed synergistic or additive anti-H. pylori activity and significantly reduced inducible nitric oxide synthase expression and Bax/Bcl-2-mediated apoptosis but enhanced Beclin-1-mediated autophagy. All mice infected with H. pylori displayed gastritis and accumulation of 3-nitrotyrosine and 4-hydroxynonenal. Pretreatment with catechins/sialic acid completely prevented H. pylori infection and resulted in normal histology. Post-treatment with catechins/sialic acid decreased the bacterial load and gastritis score and eradicated up to 60% of H. pylori infections in a dose-dependent manner. This is the first demonstration to our knowledge of a nonprobiotic, nonantibiotic treatment that is 100% effective in preventing and has promising possibilities for treating H. pylori infection. Further studies are needed to confirm this result in humans.     

Helicobacter pylori infection in children: prevalence, diagnosis and treatment outcome

The clinical significance of Helicobacter pylori infection in children remains largely unknown. The rate of acquisition at different ages has not been ascertained using reliable tests on gastric biopsies. We determined prospectively the prevalence of H. pylori infection in children and its association with gastroduodenal disease. We evaluated 240 children undergoing upper gastrointestinal endoscopy for H. pylori infection by rapid urease test, culture, ureA PCR and histopathology. Group I constituted 58 children with upper abdominal pain (UAP) and group II (controls) of 182 children without UAP who underwent diagnostic or therapeutic endoscopy for other reasons. Helicobacter pylori-positive children with UAP received anti-H. pylori therapy. Helicobacter pylori infection was significantly higher in children with UAP than controls (53.4% vs. 28%; P<0.001) and overall prevalence increased with age. On follow-up endoscopy, H. pylori had been eradicated from 82% of children with UAP; it was eradicated from the remaining 18% after a second regimen. Treated H. pylori-positive children with UAP remained symptom-free for a median of 25 months. Control children remained chronically H. pylori infected. Chronic inflammation was present in all infected children, and active inflammation in 48.8%. The study shows H. pylori infection increases with age and is strongly linked to UAP in children.     

Diabetes mellitus and Helicobacter pylori infection

Alterations of glucose metabolism in diabetes have been suggested as promoting Helicobacter pylori colonization. We performed a cross-sectional sero-prevalence study of diabetic patients (insulin-dependent, or type 1, and non-insulin-dependent, or type 2, diabetes mellitus) with H. pylori and compared them with a control group. Consecutive diabetic outpatients aged 12 to 75 y and with disease duration of greater than 1 y were enrolled. Helicobacter pylori status was evaluated by using an enzyme-linked immunosorbent assay for anti-H. pylori immunoglobulin G. Demographic data were obtained from each individual, and socioeconomic class was assessed by occupation and education level. A total of 891 individuals participated (240 with type-2 diabetes, 145 with type-1 diabetes, and 506 control subjects). After controlling for age, there was no significant difference in the prevalence of H. pylori infection in any age group. In fact, the prevalence of H. pylori was numerically higher among children in the control group than among children with type-1 diabetes (25% versus 9%, respectively; P = 0.1). Previous associations of H. pylori and diabetes may have arisen from failure to consider socioeconomic status or age. Because childhood is the most common period for acquisition of H. pylori infection, the higher prevalence of infection among the normal children as opposed to those with type-1 diabetes confirms the lack of an association.     

Green tea consumption and chronic atrophic gastritis: a cross-sectional study in a green tea production village

Chronic atrophic gastritis (CAG) is well known as a precancerous lesion of the stomach, and Helicobacter pylori (H. pylori) infection increases the risk of CAG. While recent studies have reported that green tea consumption decreases the risk of gastric cancer, there has been no study analyzing the relationship between green tea consumption and the both risks H. pylori infection and CAG. We conducted a cross-sectional study on 636 subjects living in a farming village in Japan to examine the relationship among green tea consumption, H. pylori infection, and CAG. Smoking, alcohol drinking, consumption of four beverages, including green tea, and of five foods were investigated as lifestyle factors that may affect H. pylori infection and CAG. The measurement of H. pylori-IgG antibodies was used to define H. pylori infection, and serum pepsinogens were used to define of CAG. The unconditional logistic regression model was used for analyzing each odds ratio (OR). H. pylori infection was positively associated with the risk of CAG (OR = 3.73; 95% confidence interval [CI], 2.59-5.36). High green tea consumption (more than 10 cups per day) was negatively associated with the risk of CAG, even after adjustment for H. pylori infection and lifestyle factors associated with green tea consumption (OR = 0.63; 95% CI, 0.43-0.93). These results support the hypothesis that high green tea consumption prevents CAG.     

Helicobacter pylori profile in asymptomatic farmers and non-farmers

There is a positive correlation between Helicobacter pylori infection and chronic active gastritis, peptic ulcer and gastric cancer and maltoma. There is little information on H. pylori profiles in farmers and non-farmers in the literature. Our main objective was to study the H. pylori profiles in farmers and non-formers in the United Arab Emirates. A prospective study of 151 subjects - 76 farmers and 75 non-farmers - was undertaken by determining their IgG and IgA H. pylori antibody profiles in their serum samples. Data on lifestyle were obtained from them. Eligible subjects were those who had engaged in farming for at least five years and who had not received an anti-H. pylori treatment during the six months prior to admission into the study. Most of the farmers lived in less modern accommodation, were less educated, ate their vegetable products unwashed, did not have drinking water facilities, when compared to non-farmers. Helicobacter pylori serology by IgG and IgA was positive in 112 and 77 subjects respectively (p < 0.0001). The sensitivity values for IgG and IgA serology tests were 74.2 and 51.0% respectively (p < 0.001). There were 59 and 42 H. pylori-positive farmers by IgG and IgA H. pylori serology tests respectively (p < 0.001). Among the non-farmers, the corresponding figures were 53 and 25 (p < 0.01), and neither IgG nor IgA (p = 0.4), respectively. The H. pylori serology test was able to differentiate between farmers and non-farmers. When the discordant values between IgG and IgA tests were computed for each group of subjects, the difference was significant for both farmers and non-farmers (p < 0.001 in each case). There was no difference between the farmers and non-farmers in respect of their H. pylori profiles. The farmers have a lower standard of living than non-farmers.