493 research outputs found

    Chemosensetizing and cardioprotective effects of resveratrol in doxorubicin- treated animals

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    BACKGROUND: Doxorubicin (DOX), an anthracycline antibiotic is one of the most effective anticancer drug used in the treatment of variety of cancers .Its use is limited by its cardiotoxicity. The present study was designed to assess the role of a natural product resveratrol (RSVL) on sensitization of mammary carcinoma (Ehrlich ascites carcinoma) to the action of DOX and at the same time its protective effect against DOX-induced cardiotoxicity in rats. METHODS: Ehrlich ascites carcinoma bearing mice were used in this study. Percent survival of tumor bearing mice was used for determination of the Cytotoxic activity of DOX in presence and absence of RSVL. Uptake and cell cycle effect of DOX in tumor cells in the presence of RSVL was also determined. Histopatholgical examination of heart tissues after DOX and/or RSVL therapy was also investigated. RESULTS: DOX at a dose level of 15 mg/kg increased the mean survival time of tumor bearing mice to 21 days compared with 15 days for non tumor-bearing control mice. Administration of RSVL at a dose level of 10 mg/kg simultaneously with DOX increased the mean survival time to 30 days with 70% survival of the tumor-bearing animals. RSVL increased the intracellular level of DOX and there was a strong correlation between the high cellular level of DOX and its cytotoxic activity. Moreover, RSVL treatment showed 4.8 fold inhibition in proliferation index of cells treated with DOX. Histopathological analysis of rat heart tissue after a single dose of DOX (20 mg/kg) showed myocytolysis with congestion of blood vessels, cytoplasmic vacuolization and fragmentation. Concomitant treatment with RSVL, fragmentation of the muscle fiber revealed normal muscle fiber. CONCLUSION: This study suggests that RSVL could increase the cytotoxic activity of DOX and at the same time protect against its cardiotoxicity

    Synthesis and Reactivity of 6-Iodo-4H-3,1-Benzoxazin-4-one Towards Nitrogen Nucleophiles and Their Antimicrobial Activities

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    In attempt to find new pharmacological active molecules, we synthesized 6-iodo-4H-3,1-benzoxazin-4-one and allowed it to react with some nitrogen nucleophiles namely; hydroxylamine hydrochloride, hydrazine hydrate, fomamide, aliphatic amine, aromatic amines, aralkyl amine, different amino acids, heteryl amines, ethanolamine and sodium azide to afford annelated quinazolinone derivatives and other related systems. The synthesized compounds were characterized with the help of spectroscopic techniques including IR, 1H-NMR and Mass spectra. Also their antimicrobial activities were screened against different strains of bacteria and fungi. Keywords: 6-Iodo-4H-3,1-benzoxazin-4-one; quinazolinone derivatives;  nitrogen nucleophiles; antimicrobial activity

    Characterization of Sidr (Ziziphus spp.) Honey from Different Geographical Origins

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    The current investigation was conducted to assess the melissopalynological, physicochemical, and biochemical properties, antimicrobial and antioxidant activities as well as total phenolic and total flavonoid contents of 794 Sidr honey samples collected from the Saudi market that had been imported from 12 different countries. Testing Sidr honey from different countries showed different levels of growth suppression observed against five drug resistant bacterial strains. The pathogenic strains were Staphylococcus aureus, Streptococcus mutans, Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa. The antimicrobial activity showed growth suppression levels which varied according to the origin of the honey. The comparative study of Sidr honeys revealed a strong correlation between total polyphenol and flavonoid contents and significant radical scavenging activities in particular Egyptian and Saudi Arabian honeys. The melissopalynological and physicochemical properties of different Sidr honeys complied with the recommendations of the WHO Codex Alimentarius, the European Union standards for honey quality, and the Gulf Technical Regulation on honey (GSO 147:2008-Standards Store-GCC Standardization Organization). It was concluded that Sidr honey from different geographical areas has the capacity to suppress the growth of pathogenic bacteria and perform significant radical scavenging activities

    Imaging of choroidal neovascular membrane by optical coherence tomography Angiography

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    Background: Optical coherence tomography angiography (OCTA) is a new safe imaging technique that uses motion contrast imaging to high-resolution volumetric blood stream information to produce angiographic pictures in a matter of seconds. Objectives: We aimed to identify different patterns and types of CNV by OCTA and the relationship between these patterns and activity of CNV. Patients and Methods: Fifty eyes of 50 patients presented with CNV had a regular diagnostic evaluation that included FA and/or OCT. Suspected cases with CNV underwent scanning by OCTA in this study. Patients with media opacity or bad image quality had been excluded. Results: In 80% of patients, there is a statistically significant correlation between the patterns of CNV and its activity (P-value =0.0001). Conclusion: OCTA is a critical technique for better characterizing the various forms and patterns of CNV, as well as the link between these patterns and CNV activity

    Induction of antibacterial metabolites by co-cultivation of two Red-Sea-sponge-associated actinomycetes <i>Micromonospora</i> sp. UR56 and <i>Actinokinespora</i> sp. EG49

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    Liquid chromatography coupled with high resolution mass spectrometry (LC-HRESMS)-assisted metabolomic profiling of two sponge-associated actinomycetes, Micromonospora sp. UR56 and Actinokineospora sp. EG49, revealed that the co-culture of these two actinomycetes induced the accumulation of metabolites that were not traced in their axenic cultures. Dereplication suggested that phenazine-derived compounds were the main induced metabolites. Hence, following large-scale co-fermentation, the major induced metabolites were isolated and structurally characterized as the already known dimethyl phenazine-1,6-dicarboxylate (1), phenazine-1,6-dicarboxylic acid mono methyl ester (phencomycin; 2), phenazine-1-carboxylic acid (tubermycin; 3), N-(2-hydroxyphenyl)-acetamide (9), and p-anisamide (10). Subsequently, the antibacterial, antibiofilm, and cytotoxic properties of these metabolites (1&ndash;3, 9, and 10) were determined in vitro. All the tested compounds except 9 showed high to moderate antibacterial and antibiofilm activities, whereas their cytotoxic effects were modest. Testing against Staphylococcus DNA gyrase-B and pyruvate kinase as possible molecular targets together with binding mode studies showed that compounds 1&ndash;3 could exert their bacterial inhibitory activities through the inhibition of both enzymes. Moreover, their structural differences, particularly the substitution at C-1 and C-6, played a crucial role in the determination of their inhibitory spectra and potency. In conclusion, the present study highlighted that microbial co-cultivation is an efficient tool for the discovery of new antimicrobial candidates and indicated phenazines as potential lead compounds for further development as antibiotic scaffold

    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

    The Bioactive Value of Tamarix gallica Honey from Different Geographical Origins

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    This study was conducted to assess the bioactive value of Tamarix gallica honey samples collected from three countries. In total, 150 Tamarix gallica honey samples from Saudi Arabia (50), Libya (50), and Egypt (50) were collected and compared, based on the results of the melissopalynological analysis, their physicochemical attributes, antioxidant and antimicrobial activities, and biochemical properties, together with their total phenolic and total flavonoid contents. Depending on the geographical origin, we observed different levels of growth suppression for six resistant bacterial strains. The pathogenic microorganisms tested in this study were Staphylococcus aureus, Streptococcus mutans, Klebsiella pneumoniae, Escherichia coli, Proteus vulgaris, and Pseudomonas aeruginosa. There was a strong correlation between the polyphenol and flavonoid contents, as well as significant (p < 0.05) radical scavenging activities. The melissopalynological analysis and physicochemical properties complied with the recommendation of the Gulf and Egyptian Technical Regulations on honey, as well as the Codex Alimentarius of the World Health Organization and the European Union Normative related to honey quality. It was concluded that Tamarix gallica honey from the three countries has the capacity to suppress pathogenic bacterial growth and has significant radical scavenging activities. Moreover, these findings suggest that Tamarix gallica honey may be considered as an interesting source of antimicrobial compounds and antioxidants for therapeutical and nutraceutical industries or for food manufacturers

    The genus <i>Micromonospora</i> as a model microorganism for bioactive natural product discovery

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    This review covers the development of the genus Micromonospora as a model for natural product research and the timeline of discovery progress from the classical bioassay-guided approaches through the application of genome mining and genetic engineering techniques that target specific products. It focuses on the reported chemical structures along with their biological activities and the synthetic and biosynthetic studies they have inspired. This survey summarizes the extraordinary biosynthetic diversity that can emerge from a widely distributed actinomycete genus and supports future efforts to explore under-explored species in the search for novel natural products

    Optimized spray-dried conditions' impact on fatty acid profiles and estimation of in vitro digestion of spray-dried chia/fish oil microcapsules

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    Long-chain polyunsaturated fatty acids (LCPUFA) are of interest due to their potential health properties and have a significant role in reducing the risk of various chronic diseases in humans. It is commonly used as a supplement. However, lipid oxidation is an important negative factor caused by environmental, processing, and limited water solubility of LCPUFA, making them difficult to incorporate into food products. The objective of this research work was to prevent oxidation, extend shelf life, enhance the stability of fatty acids, and to achieve controlled release by preparing spray-dried powder (SDM). For spray-drying, aqueous emulsion blends were formulated using a 1:1 ratio of chia seed oil (CSO) and fish oil (FO) and using a laboratory-scale spray-dryer with varying conditions: inlet air temperature (IAT, 125-185 °C), wall material (WM, 5-25%), pump speed (PS, 3-7 mL/min), and needle speed (NS, 3-11 s). The maximum alpha-linolenic acid (ALA) content was 33 ± 1%. The highest values of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the microcapsules were 8.4 ± 0.4 and 13 ± 1%, respectively. Fourier transform infrared and X-Ray diffraction analysis results indicated that SDM was successfully formulated with Gum Arabic and maltodextrin (MD). The blending without encapsulation of CSO and FO was digested more efficiently and resulted in more oil being released with simulated gastric fluid (SGF), simulated intestinal fluid (SIF), and SGF + SIF conditions without heating. No significant changes were observed for saturated, monounsaturated, and LCPUFA, whether exposed or not to gastrointestinal conditions. However, compared to the release of SDM, it can be useful for designing delivery systems for the controlled release of essential fatty acids.info:eu-repo/semantics/publishedVersio

    Significance of selenium in ameliorating the effects of irrigation deficit via improving photosynthesis efficiency, cell integrity, osmo-protectants, and oil profile of anise crop

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    Anise is one of the plants with therapeutic potential, which is classified among the most important medicinal plants with interesting biological effects. Its components could be perceived so as “natural” and “safe” alternatives to antibiotics as well as they are applied in different industries such as food and cosmetic purposes. Selenium (Se) is an essential micronutrient, however, its importance to improve oil yield and quality of anise has not been adequately investigated, specifically under drought. Therefore, two successive seasons were conducted to investigate the effect of selenium foliar application upon anise plants under drought stress. Selenium was applied at three different concentrations (0.0 1.0 and 2.0 mM denoted Se0, Se1 and Se2, respectively) along with two levels of crop evapotranspiration (ET): Full irrigation, 100% of ET (FI) and 60% of ET (DI). The promotive effect of combinations of DI × Se1 or Se2 (for Fv/Fm, RWC%, and MSI% in the first season) and DI × Se2 (for Fv/Fm, and MSI% in the second season) were as similar as FI × Se2. Compared to the counterpart control treatment (DI × Se0), the highest increases in total free amino acids (31.5 and 31.6%), total soluble sugars (84.2 and 86.4%) and free proline content (84.2 and 86.4%) were recorded with application of DI × Se2 practice in both seasons, respectively. Under DI, Se2 recorded the maximum values of root length, shoot fresh weight and shoot dry weight in the second season. Under drought, the increases in seed yield due to application of Se1 and Se2 amounted to 1.72 and 1.62 folds in the 1st season and 1.50 and 1.43 folds in 2nd one, respectively. The most effective practice for improving IWUE was Se1× DI in both seasons, followed by Se2 × DI. Based on the chromatographical detection, the maximum values of Anethole were recorded with FI × Se2 while L-Linalool has greatly increased with DI × Se2. In conclusion, the growers in arid and semi-arid zones are advised to use selenium (2.0 mM) in anise fertilization to mitigate the adverse impacts of drought, and keeping crop yield and quality
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