20 research outputs found

    Phenolic Compounds from Artichoke (Cynara scolymus L.) By-products and their Antimicrobial Activities

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    Cynara scolymus L. is a medicinal plant frequently used in traditional medicine for liver diseases. The aim of this study is to evaluate the antimicrobial activity of the different parts of Artichoke. Maximum antimicrobial activity was observed with methanolic extract of bound phenols for (bract and heart) against Gram negative bacteria. The MIC values for bound phenols from heart were (63?g/ml). Whereas, the bound phenols for bracts was ranged from (312 and 486?g/ml) against Gram negative and (486?g/ml) against Gram positive. Free phenols of the heart of artichoke showed the lowest MIC (204 to 206) ?g/mL for microorganism Gram positive and Gram negative. Therefore, this study indicate that the free phenolic extract from bracts of Cynara scolymus L. might be of interest within the developing market of nutritional ingredients and is capable of yielding nutritional supplements with antimicrobial activities. Key words: artichoke wastes, antibacterial effect

    A Comparative Study on the Active Constituents, Antioxidant Capacity and Anti-Cancer Activity of Cruciferous Vegetable Residues

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    أجريت هذه الدراسة لتقييم كفاءة وفعالية مخلفات أربعة أنواع من خضروات العائلة الصليبية (البراسيكا) تم ستخلاصهم بمذيبين (الميانولي  - المائي) وهم كاتالي البروكولي ، كرنب بروكسل ، القرنبيط ، الفجل الأحمر. وتم تقييم المستخلصات من حيث محتواها الكلي من المركبات الفعالة مثل الفينولات و الفلاڤونيدات والتانينات وڤيتامين سي واتعرف عليها بالـ HPLC ودراسة نشاطاتها المضادة للأكسدة بأكثر من طريقة مثل الـ DPPH· والـ Fe2+-chelating والـ Reducing power وكذلك دراسة كفاءتها في كبح جماح ومنع إنتشار وتكاثر ثلاثة أنواع من الخلايا السرطانية للإنسان علي النطاق المعملي مثل خلايا سرطان الكبد HePG2 و خلايا سرطان القولون HTC116 وخلايا سرطان الثدي MCF7. أظهرت النتائج أن المستخلص الميثانولي لمخلفات البروكولي وكرنب بروكسيل أعطي أعلي محتوي من المركبات الفعالة و أعلي نشاط مضاد للأكسدة في كبح جماح الشق الحر الـ DPPH· و وأعلي قدرات إختزلية ضد الحديديك الـ Reducing power. بينما أظهر المستخلص المائي لكل من كرنب بروكسيل والقرنبيط اعلى نشاط في عملية خلب الحديدوز الـ Fe2+-chelating. أكد تحليل HPLC للتعرف علي المركبات الفينولية الموجودة في مستخلصات مخلفات خضروات البراسيكا التي تم التعرف عليها أن المستخلص الميثانولي يمتلك كميات مرتفعة من الكاتشين والروتين والكيوماريك والبنزويك و الليتيولين. كما أظهر المستخلص الميثانولي لمخلفات كرنب بروكسيل تأثيراً مثبطاً و مانع للإنتشار وقاتل مع كافة أنواع الخلايا السرطانية وكان ذلك متبوعاً بالبروكولي والفجل الاحمر على التوالي. أكدت هذه النتائج أن مخلفات كرنب بروكسيل تحتوي على مركبات كيميائية فعالة يمكنها أن تمنع تكاثر الخلايا السرطانية. لذلك ، اقترحت هذه النتائج أن مخلفات خضروات البراسيكا يمكن إستخدامها كمضادات أكسدة قوية ومضادة لإنتشار الخلايا السرطانية وذلك في تطبيقات الصناعات الغذائية و الدوائية.This study is pointed out to estimate the effectiveness of two solvents in the extraction and evaluating the active ingredients and their antioxidant activity as well as anti-cancer efficiency. Therefore, residues from four different Brassica vegetables viz. broccoli, Brussels sprout, cauliflower, and red cherry radish were extracted using two procedures methods: methanolic and water crude extracts. Methanol extracts showed the highest content of total phenolic (TP), total flavonoids (TF), and total tannins (TT) for broccoli and Brussels sprouts residues. Methanolic extract of broccoli and Brussels sprouts residues showed the highest DPPH· scavenging activity (IC50 = 15.39 and 18.64 µg/ml). The methanol and water extracts of Brussels sprout residues showed the highest chelating activity (IC50 = 11.77 and 5.94 µg/ml) and exhibited the highest reducing power (EC50 =14.38 and 20.18 µg/ml) with broccoli respectively. The HPLC analysis of phenolic compounds confirmed that the methanol extract of all the residues examined possessed high amounts of catchine, rutin, cumaric, benzoic, and luteolin. The methanol extract at 100 µg/ml of Brussels sprouts residues displayed a rise cytotoxic effect on HePG2 (80.40%), MCF7 (75.49%) and HCT116 (22.74%) followed by broccoli and red cherry radish, respectively. This result confirmed that Brussels sprouts residue contain effective chemical compounds that can inhibit the proliferation of cancer cells. Therefore, these results proposed that those Brassica vegetable residues might be beneficial as a potent antioxidant and anticancer agents and strongly recommended as fixing in constituent's food applications and pharmaceutical industries

    Ascorbic Acid Induces the Increase of Secondary Metabolites, Antioxidant Activity, Growth, and Productivity of the Common Bean under Water Stress Conditions

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    One of the most vital environmental factors that restricts plant production in arid and semi-arid environments is the lack of fresh water and drought stress. Common bean (Phaseolus vulgaris L.) productivity is severely limited by abiotic stress, especially climate-related constraints. Therefore, a field experiment in split-plot design was carried out to examine the potential function of ascorbic acid (AsA) in mitigating the adverse effects of water stress on common bean. The experiment included two irrigation regimes (100% or 50% of crop evapotranspiration) and three AsA doses (0, 200, or 400 mg L−1 AsA). The results revealed that water stress reduced common bean photosynthetic pigments (chlorophyll and carotenoids), carbonic anhydrase activity, antioxidant activities (2,2-diphenyl-1-picrylhydrazyl free radical activity scavenging activity and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation assay), growth and seed yield, while increased enzymatic antioxidants (peroxidase), secondary metabolites (phenolic, flavonoids, and tannins), malondialdehyde (MDA), and crop water productivity. In contrast, the AsA foliar spray enhanced all studied traits and the enhancement was gradual with the increasing AsA dose. The linear regression model predicted that when the AsA dose increase by 1.0 mg L−1, the seed yield is expected to increase by 0.06 g m−2. Enhanced water stress tolerance through adequate ascorbic acid application is a promising strategy to increase the tolerance and productivity of common bean under water stress. Moreover, the response of common bean to water deficit appears to be dependent on AsA dose

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

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    Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

    Fault‐tolerant modular multilevel converter for a seamless transition between stand‐alone and grid‐connected microgrid

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    Abstract Recently, renewable distributed generation (DG) systems have emerged to improve the power system security and reliability while reducing the environmental incompatibility of fossil fuel power plants. DG could operate either as a standalone and/or as a grid‐connected power system. The interfacing circuits of DG and their controls have to comply with utility quality regulations and afford a seamless transition from online to offline and vice versa. This article advises a simple and robust control scheme for a modular multilevel converter (MMC) that interfaces with a photovoltaic (PV) generator. The proposed control method ensures high‐quality output voltage/current waveform in online and/or offline operating modes. Moreover, the proposed control provides a seamless and swift transition from standalone to grid‐connected and vice versa. The exhibited control scheme is simulated with MATLAB/Simulink. Real‐time simulator OPAL‐RT OP4510 is used to verify the displayed simulation results. The simulation results determine the accomplishment of the proposed control technique for a seamless transition from the grid‐connected mode to the standalone mode and vice versa via MMC

    Antioxidant activities of phenolics, flavonoids and vitamin C in two cultivars of fennel (Foeniculum vulgare Mill.) in responses to organic and bio-organic fertilizers

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    Field experiment was conducted to study the effect of organic and bio-organic fertilizers on dry weight; yield, total phenolics (TPC), total flavonoids (TFC), vitamin C and on their antioxidant activities of two sweet fennel cultivars Dolce and Zefa fino. Results strongly showed that there were significant differences between sweet fennel cultivars. Generally the highest values of all parameters were obtained when fennel plants were supplemented with 50% NPK + 50% organic fertilizer and bio fertilizer when compared with control treatment. The highest values of TPC, TFC and Vit. C were recorded by Zefa fino cultivar when received 50% NPK + 50% organic treatment. The antioxidant activities of both cultivars were evaluated and Dolce cultivar showed the highest DPPH·− scavenging activity expressed as IC50 compared with Zefa fino cultivar. In addition, Dolce cultivars exhibited the highest value for Fe2+-chelating activities for organic and bio-organic fertilizers followed by Zefa fino when compared to control treatment. Dolce cultivar generally showed superiority than Zefa fino in all measured parameters

    Enhancement of phenolics, flavonoids and glucosinolates of Broccoli (Brassica olaracea, var. Italica) as antioxidants in response to organic and bio-organic fertilizers

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    A field experiment was carried out to study the effect of organic and bioorganic fertilizers on growth parameters, yield and the quality of two broccoli cultivars (Calabrese and Southern star). Bio-organic fertilizers gave better results for all vegetative growth parameters for Southern star cultivar compared to Calabrese cultivar. Total phenolic content (TPC), total flavonoid content (TFC) and total glucosinolates content (TGsC) were almost higher in Calabrese cultivar as a result of organic fertilizer treatment. The antioxidant activities of both cultivars were evaluated and Calabrese cultivar showed the higher1, 1-diphenyl-2-picrylhydrazyl DPPH. scavenging activity expressed as IC50 (its concentrations for 50% inhibition) (16.56 μg/ml) compared to Southern star (19.42 μg/ml). In addition, Calabrese cultivar showed the higher chelating power (75.36 μg/ml) than Southern star (72.43 μg/ml) at (30 μg/ml) when the organic fertilizer was applied. The results indicated that there is a good margin for enhancing antioxidant compounds of broccoli for economic production using organic fertilization. This study indicated the potential application of broccoli as a potent natural source of antioxidants as nutraceuticals
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