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1.
Indian black tea; CTC leaf and dust, produced by Tata Tea Limited, Kolkata, (India) was studiedin vitro as potential scavenger of oxygen free radicals. Super oxide anions were generated in a system containing xanthine—xanthine oxidase (enzymic system) and by NADH- phenozine methosulphate (non enzymic system). Anions were assayed in terms of uric acid formation and reduction of nitroblue tetrazolium salt, which were shown to be suppressed by tea extracts. Extracts from both leaf and dust also inhibted the formation of hydroxyl radicalsin vitro in the enzymic system comprising hypoxanthine—Cu+2—sodium ascorbate and xanthine oxidase and in non enzymic system of deoxyribose—Cu+2—sodium ascorbate and H2O2 as well as the Cu+2 induced lipid peroxidation in human low density lipoprotein. Feeding with black tea in normal rats for sixty days increased their antioxidant activity and their liver microsomes were shown to be protected against peroxidation of lipids as stimulated by metal ions with enzymic or non enzymic reactants. Furthermore feeding with tea extracts in normal as well as triton WR—1339 induced hyperlipidemic rats caused decrease in their plasma levels of total cholesterol, phospholipids and triglycerides. The antioxidant and lipid lowering activities of both extracts from CTC leaf and dust tea was comparable and may be due to the presence of natural products like catechin and others.  相似文献   

2.
Grapes are the richest source of antioxidants due to the presence of potent bioactive phytochemicals. In this study, the phytochemical contents, scavenging activities and protective role against H2O2-induced oxidative stress in liver tissue ex vivo of four grape (Vitis vinifera) cultivars extracts, namely Flame seedless (black), Kishmish chorni (black with reddish brown), Red globe (red) and Thompson seedless mutant (green), were evaluated. The total phenolics and flavonoids content in pulp or skin fractions of different grape cultivars were in the range of 47.6–310 mg gallic acid equivalent/g fresh weight (fw), and 46.6–733.3 µg catechin equivalent/g fw respectively. The scavenging activities in skin of different grape varieties against 2,2-diphenyl-1-picrylhydrazyl (44–58 %), hydrogen peroxide (15.3–18.6 %), and hydroxyl radicals (50–85 %), were higher than pulp of the corresponding cultivars. These scavenging activities of grape extracts were found to be significantly (p < 0.01) correlated with the levels of total phenols, flavonoids and ascorbic acid. Liver tissues from goat treated with H2O2 (500 μM) showed significantly decreased GSH content by 42.9 % and activities of catalase by 50 % and glutathione reductase by 66.6 %; while increased thiobarbituric acid reactive substances and nitric oxide level by 2.53- and 0.86-fold, respectively, and activity of glutathione S-transferase by 0.96-fold. Grape skin extracts showed the stronger protective activity against H2O2-induced oxidative stress in liver tissue ex vivo, than its pulp of any cultivar; and the Flame seedless (black) cultivar showed the highest potential. In conclusion, our study suggested that the higher antioxidant potential, phytochemical contents and significant scavenging capacities in pulp and skin of grape extracts showed the protective action of grape extracts against H2O2-induced oxidative stress in liver tissue ex vivo.  相似文献   

3.
四川边茶提取物对脂肪酸合酶的抑制作用   总被引:2,自引:0,他引:2  
四川边茶(康砖)是黑茶的一个主要品种,所含茶多酚与绿茶和红茶不同。本研究利用酶动力学方法测定了边茶萃取物对脂肪酸合酶(Fatty Acid Synthase, FAS, E.C. 2.3.1.85)的抑制作用,近几年研究报道该酶是减肥和抑癌的双重潜在靶点。结果表明,边茶萃取物对FAS有可逆和不可逆抑制双重作用,最佳萃取溶剂为50%的乙醇,在常温下5 h即可达到最佳萃取效果。用开水泡茶的方法经两次浸取可提取出近60%的抑制FAS有效物,比绿茶的浸出效率约高1倍,但需较长的浸泡时间。边茶的新茶对脂肪酸合酶的抑制能力并不强,存放数年的边茶抑制能力最好,其后有所下降,但大部分抑制活性可保持20年以上,而30年以上保存期可能会使抑制能力明显下降。边茶提取物与底物乙酰辅酶A和丙二酸单酰辅酶A的竞争性质都是竞争性与非竞争性的混合型;对FAS中的酮酰还原反应的抑制不明显,这说明酮酰还原酶结构域并不是其主要作用位点;这些和绿茶及红茶都有不同。由实验结果分析边茶中的抑制剂不同于红茶和绿茶,可能是茶多酚中的茶褐素,其抑制能力高于儿茶素而接近茶黄素。这些结果表明边茶在减肥、抑癌等方面可能具有良好的应用前景。  相似文献   

4.
Elevated free radical generation in inflamed joints and impaired antioxidant system has been implicated in rheumatoid arthritis (RA). Green tea extracts (GTE) have been shown to reduce inflammation in inflammatory arthritis murine model. This study investigates possible mechanisms by which vitamin C and GTE protect joints in RA rat model. This study included forty adult male rats that were divided into four groups (10 rats each); control group, collagen II induced RA group (CII), CII treated with vitamin C (CII + Vit C) and CII treated with GTE (CII + GTE) in physiology laboratory, Assiut University, Egypt. After 45 days of treatment, plasma levels of lipid peroxides (LPO), nitric oxide (NO), ceruloplasmin (CP), superoxide dismutase (SOD), uric acid (UA) and glutathione (GSH) were detected using colorimetric methods, PGE2 using ELISA and copper (Cu) and zinc (Zn) using spectrometer. In CII group, levels of LPO, NO, PGE2, UA, CP, Cu were higher while SOD, GSH, Zn were lower than controls. In groups treated with vitamin C and GTE, levels of SOD, GSH were increased while levels of LPO, NO, PGE2, Cu, CP were decreased compared with CII group. Levels of UA were decreased and Zn increased in GTE treated group compared with CII group. GTE treated group showed higher Zn and low Cu levels compared with vitamin C treated group. This study suggests proper GTE and vitamin C intake may effectively normalize the impaired oxidant/antioxidant system and delaying complication of RA.  相似文献   

5.
分光光度法测定蒙古栎叶中多酚的含量   总被引:2,自引:0,他引:2  
以没食子酸为标准品,使用福林酚试剂(FC),通过分光光度法,对蒙古栎树叶中植物多酚含量进行了测定.首先从方法的稳定性、线性关系、精确性和准确性角度,对FC法进行了调整,确定了以没食子酸为标准的最佳反应条件.结果表明,最佳反应条件为0.15mL FC试剂(1mol/L),0.15mL 10%体积分数的Na2CO3,25℃反应80min后于760nm处测吸光值.使用调整后的方法测得结果为:蒙古栎叶中总酚含量为6.39%,RSD为1.90%.方法操作简单,结果重现性好, 可用来测定蒙古栎叶中总酚的含量.  相似文献   

6.
7.
目的】探索内容质量建设的有效途径,为国内期刊提供参考与借鉴。【方法】以《中国肿瘤临床》为例,介绍其立足学科建设、发挥学会优势、加强优秀选题与组稿等一系列举措,总结经验与体会。【结果】《中国肿瘤临床》的内容质量与学术影响力得到显著提升,分别于2013年与2015年获得中国科协精品科技期刊项目资助。【结论】内容质量是期刊发展的基石与核心,科技期刊应积极研究与开拓,调动一切有利资源,打造学术精品。  相似文献   

8.
BackgroundIn fish farming, the plant extracts containing antioxidant compounds have been added to the diet for enhancing pathogen resistance. In vitro studies evaluating the antioxidant effect of herbal extracts on fish cell models have focused on ROS production and the respiratory burst mechanism. However, the effects on enzymatic antioxidant defense on salmon leukocytes have not been evaluated. This study aims to evaluate the enzymatic antioxidant defense and ROS-induced cell damage in Salmon Head Kidney-1 (SHK-1) cell line exposed to polyphenol-enriched extract from Sambucus nigra flowers.ResultsFirstly, the Total Reactive Antioxidant Power (TRAP) assay of elderflower polyphenol (EP) was evaluated, showing 459 and 489 times more active than gallic acid and butyl hydroxy toluene (BHT), respectively. The toxic effect of EP on salmon cells was not significant at concentrations below 120 µg/mL and no hemolysis activity was observed between 20 and 400 µg/mL. The treatment of SHK-1 cell line with EP decreased both the lipid peroxidation and protein oxidation induced by H2O2, which could be associated with decreasing oxidative stress in the SHK-1 cells since the GSH/GSSG ratio increased when only EP was added.ConclusionsThese results suggest that plant extracts enriched with polyphenols could improve the enzymatic antioxidant defense of salmon leukocytes and protect the cells against ROS-induced cell damage.How to cite: Santana PA, Jara-Gutiérrez C, Mellado M, et al. Effects of elderflower extract enriched with polyphenols on antioxidant defense of salmon leukocytes. Electron J Biotechnol 2021;51. https://doi.org/10.1016/j.ejbt.2021.04.004  相似文献   

9.
BackgroundEndometritis is the most common disease of dairy cows and traditionally treated with antibiotics. Lactic acid bacteria can inhibit the growth of pathogens and also have potential for treatment of endometritis. Using PacBio single-molecule real-time sequencing technology, we sequenced the full-length l6S rRNA of the microbiota in uterine mucus samples from 31 cows with endometritis, treated with lactic acid bacteria (experimental [E] group) and antibiotics (control [C] group) separately. Microbiota profiles taken before and after treatment were compared.ResultsAfter both treatments, bacterial species richness was significantly higher than before, but there was no significant difference in bacterial diversity. Abundance of some bacteria increased after both lactic acid bacteria and antibiotic treatment: Lactobacillus helveticus, Lactococcus lactis, Lactococcus raffinolactis, Pseudomonas alcaligenes and Pseudomonas veronii. The bacterial species that significantly decreased in abundance varied depending on whether the cows had been treated with lactic acid bacteria or antibiotics. Abundance of Staphylococcus equorum and Treponema brennaborense increased after lactic acid bacteria treatment but decreased after antibiotic treatment. According to COG-based functional metagenomic predictions, 384 functional proteins were significantly differently expressed after treatment. E and C group protein expression pathways were significantly higher than before treatment (p < 0.05).ConclusionsIn this study, we found that lactic acid bacteria could cure endometritis and restore a normal physiological state, while avoiding the disadvantages of antibiotic treatment, such as the reductions in abundance of beneficial microbiota. This suggests that lactic acid bacteria treatment has potential as an alternative to antibiotics in the treatment of endometritis in cattle.How to cite: Yang L, Huang W, Yang C, et al. Using PacBio sequencing to investigate the effects of treatment with lactic acid bacteria or antibiotics on cow endometritis. Electron J Biotechnol 2021:51. https://doi.org/10.1016/j.ejbt.2021.02.004  相似文献   

10.
BackgroundThe roots of chicory and the tubers of Jerusalem artichoke are used for the production of inulin. However, a quality of tubers and roots, i.e. the content of inulin, monosaccarides and disaccharides, depends on the activity of enzymes implicated in the metabolism of inulin. The knowledge on the changes of activities of inulin synthesizing and degrading enzymes is limited during plant sprouting, growth and dormancy. It happens due to complicated measurements of the product of enzymatic reaction in the presence of crude plant extract. Fructan exohydrolase (β-d-fructan fructohydrolase, FEH, EC 3.2.1.80) is an enzyme responsible for the hydrolysis of fructans in plants. For fructose as the reaction product measurement, a high-performance liquid chromatography is usually used. The aim of the study was to choose a simple and suitable method for FEH activity determination and the measurement of fructose in the presence of plant extracts.ResultsTwo chemical methods, i.e. copper(II)–neocuproine and 3,5-dinitrosalicylic acid, and the enzymatic one based on the reactions catalyzed by hexokinase, phosphoglucose isomerase and glucose-6-phosphate dehydrogenase were used. Enzymatic method was found to be suitable for FEH activity determination in plant extracts, and on the contrary to chemical methods no interference effects of compounds from crude plant extracts were observed.ConclusionEnzymatic method is applicable for the routine analysis and will allow performing the investigations without special equipment on the inulin degrading enzyme in biotechnologically important crops.  相似文献   

11.
罗小梅  邓慧群  邱勇娟  黄婷婷 《大众科技》2012,14(4):185-186,259
对金牡丹等15个乌龙茶品种在广西桂林区试点与黄旦品种进行种植成活率、新梢生育期、发芽密度、生长势等方面的对比鉴定,在同等条件下探索其生长特性,为评定新品种提供科学依据。  相似文献   

12.
IntroductionMoving average (MA) is one possible way to use patient results for analytical quality control in medical laboratories. The aims of this study were to: (1) implement previously optimized MA procedures for 10 clinical chemistry analytes into the laboratory information system (LIS); (2) monitor their performance as a real-time quality control tool, and (3) define an algorithm for MA alarm management in a small-volume laboratory to suit the specific laboratory.Materials and methodsMoving average alarms were monitored and analysed over a period of 6 months on all patient results (total of 73,059) obtained for 10 clinical chemistry parameters. The optimal MA procedures were selected previously using an already described technique called the bias detection simulation method, considering the ability of bias detection the size of total allowable error as the key parameter for optimization.ResultsDuring 6 months, 17 MA alarms were registered, which is 0.023% of the total number of generated MA values. In 65% of cases, their cause was of pre-analytical origin, in 12% of analytical origin, and in 23% the cause was not found. The highest alarm rate was determined on sodium (0.10%), and the lowest on calcium and chloride.ConclusionsThis paper showed that even in a small-volume laboratory, previously optimized MA procedures could be successfully implemented in the LIS and used for continuous quality control. Review of patient results, re-analysis of samples from the stable period, analysis of internal quality control samples and assessment of the analyser malfunctions and maintenance log have been proposed for the algorithm for managing MA alarms.  相似文献   

13.
苹果梨叶片几种生理生化指标对梨上瘿螨为害的响应   总被引:4,自引:0,他引:4  
梨上瘿螨Epitrimerus pyri(Nalepa)为害苹果梨Pyrus bretschneideriRehd.叶片后,一些生理生化指标发生了变化.经光谱技术、化学方法和电物理方法测定,与健康叶片相比受害部位的叶绿素含量下降50·05%,可溶性糖含量下降19·86%,可溶性蛋白质含量上升29·17%,游离氨基酸含量上升21·59%,游离脯氨酸含量上升107·03%,过氧化氢酶活性增加22·62%,膜透性增加150·43%,而且受害部位周围组织的生理生化指标也发生了变化.  相似文献   

14.
[目的]根据论文的特点,从信息质量理论中提炼出有助于提高编辑初审工作质量的有效方法。[方法]根据Strong D M等人提出的信息质量定义,演绎推理论文信息质量的定义;根据信息质量的PSP/IQ模型,结合论文的特点和初审实践,从中归纳概括论文信息质量的维度,从而形成编辑初审的"论文信息质量5维法"。[结果]提出了学术期刊论文信息质量的概念,并探究了它的5个维度,形成了相应的论文信息质量5维法作为编辑初审的一种新方法。[结论]论文信息质量5维法在事实上和理论上都为编辑初审工作提供了一种可资借鉴的新思路和新方法。  相似文献   

15.
The uncontrolled hyperglycemia can lead to disturbances in the cell structure and functions of organs. This study was performed to analyze the “differential proteome” change in rat liver associated with diabetes mellitus in relation to effects of an anti-diabetic herb, Cynodon dactylon leaf extracts. Rats were intraperitoneally injected with alloxan (150 mg/kg/bw) and treated with C. dactylon leaf extracts (450 mg/kg/bw/day/orally). The liver proteins were subjected to proteome analysis using the advanced technologies i.e., 2D electrophoresis (2-DE) and mass spectrometry. Comparison of 2-DE protein distribution profiles among the livers from normal, alloxan-induced diabetic rats and alloxan-induced diabetic rats treated with C. dactylon leaves identified three proteins that were up-regulated in alloxan-induced diabetic rats i.e., nucleophosmin, l-xylulose reductase and carbonic anhydrase III which are known to be mainly involved in ribosome biogenesis, centrosome duplication, cell proliferation, tumor suppression, glucose metabolism, osmo-regulation, water–CO2 balance and acid–base balance. These results help us to understand the elucidation of molecular mechanism connected to liver function and insulin associated with diabetes mellitus. These identified proteins were primarily involved in cell proliferation and homoeostasis of liver tissues upon the treatment with C. dactylon leaf extracts.  相似文献   

16.
BackgroundRosemary (Rosmarinus officinalis) contains active substances that have desirable properties for industrial and herbal medicine applications, e.g., essential oils (1.5–2.5%), tannins, flavonoids, triterpenes, saponins, resins, phytosterols, rosmarinic acid and many others. The aim of this study was to determine the influence of rosemary extract and 20% rapeseed oil substitution for animal fat on storage changes and inhibition of cholinesterases in liver pâté.ResultsPreliminary research showed that rosemary extract exhibited antioxidative activity in the system of accelerated Rancimat and Oxidograph tests. Then, rosemary extract was used as an ingredient in liver pâté. During the experiment, meat samples were refrigerated and tested on days 1, 5, 8, 12 and 15 after production. The study proved that the substitution of 20% of animal fat with rapeseed oil decreased the content of saturated acids and increased the content of monoenic fatty acids by approximately 5% and polyene fatty acids by 40%.ConclusionsIn addition to antioxidative activity, the rosemary extract affected the health-promoting value of the samples, which inhibited cholinesterase activity during the entire storage period. The extract inhibited AChE more than BChE.How to cite: Bilska A, Kobus-Cisowska J, Kmiecik D, et al. Cholinesterase inhibitory activity, antioxidative potential and microbial stability of innovative liver pâté fortified with rosemary extract (Rosmarinus officinalis). Electron J Biotechnol 2019;40. https://doi.org/10.1016/j.ejbt.2019.03.007  相似文献   

17.
BackgroundAlgae offer many advantages as biofuel sources including: high growth rates, high lipid content, the ability to grow on non-agricultural land, and the genetic versatility to improve strains rapidly and produce co-products. Research is ongoing to make algae biofuels a more financially attractive energy option; however, it is becoming evident that the economic viability of algae-based fuels may hinge upon high-value co-products. This work evaluated the feasibility of using a co-product, algae extract, as a nutrient source in cell culture media.ResultsAlgae extract prepared from autolysed Chlamydomonas reinhardtii was found to contain 3.0% protein, 9.2% total carbohydrate, and 3.9% free α-amino acid which is similar to the nutrient content of commercially available yeast extract. The effects of algae extract on the growth and metabolism of laboratory strains of Escherichia coli and Saccharomyces cerevisiae were tested by substituting algae extract for yeast extract in LB and YPAD growth media recipes. Complex laboratory media supplemented with algae extract instead of yeast extract showed markedly improved effects on the growth and metabolism of common laboratory microorganisms in all cases except ethanol production rates in yeast.ConclusionsThis study showed that algae extract derived from C. reinhardtii is similar, if not superior, to commercially available yeast extract in nutrient content and effects on the growth and metabolism of E. coli and S. cerevisiae. Bacto™ yeast extract is valued at USD $0.15–0.35 per gram, if algae extract was sold at similar prices, it would serve as a high-value co-product in algae-based fuel processes.  相似文献   

18.
For the estimation of copper, diethyldithiocarbamate method is most commonly employed in various laboratories where atomic absorption spectrophotometer is not available. The prevalence rate of gastrointestinal malignancies is very high in Kashmir as compared to other parts of the world. We could find high serum copper levels in gastrointestinal tract cancer. Intake of salted tea, prepared in copper vessel, is very common in Kashmir. Such tea samples showed copper value as 3168.9 (S.D. 700.5) μg/dl estimated by diethyldithiocarbamate method. When these samples analysed by atomic absorption spectrophotometer, the copper levels were just 9% as reported by colorimetric method. Various black salted tea samples were prepared in the laboratory in glass vessel. The mean copper was 1115.0 (S.D. 350.4) μg/dl. After addition of milk, the values were reduced by 50%. Nine phenolic compounds showed varying amount of copper by colorimetric method and no copper could be detected by atomic absorption spectrophotometer. Phenolic compounds present in tea leaves interfere in the estimation of copper by diethyldithiocarbamate method. It is suggested that diethyldithiocarbamate colorimetric method for copper estimation is not suitable for solutions containing phenolic compounds.  相似文献   

19.
Objective of this study was to obtain a better understanding of the mechanism responsible for the d-galactosamine (d-GalN) induced hepatotoxicity and to study the effect of catechin against d-GalN induced hepatotoxicity. Catechin 50 and 100 mg/kg b.wt was administered for 1 week by oral route. Liver damage was induced by intra-peritoneal administration of 400 mg/kg b.wt d-galactosamine on the last day of catechin treatment. At the end of treatment all animals were killed and liver enzyme levels were estimated. Dissected hepatic samples were used for histopathology, RNA isolation, expression studies of Bax, Bcl-2 and p53 mRNA levels and mitochondrial membrane potential studies. We found that increases in the liver enzyme activity and decrease in antioxidant enzyme activity by d-GalN were significantly restricted by oral pretreatment with catechin. Disruption of mitochondrial membrane potential, up regulation of p53, Bax and down regulation of Bcl-2 mRNA levels in the liver of d-GalN intoxicated rats were effectively prevented by pretreatment with catechin.  相似文献   

20.
臭氧水对榨菜和萝卜的灭菌效果研究   总被引:1,自引:0,他引:1  
研究了臭氧水浓度和处理时间对榨菜和萝卜的灭菌效果及对其理化成分和感官品质的影响.结果表明,不同浓度的臭氧水处理均能显著降低榨菜和萝卜的微生物含量,当臭氧浓度为1.1 mg-L以上时,菌落总数可降低90%以上,大肠菌群基本为零.而臭氧水处理后的榨菜和萝I-的总酸、总糖、蛋白质含量及感官质量均无显著变化.  相似文献   

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