12 research outputs found

    Antioxidant activity of tokaj essence

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    The aim of the presented experiment was to measure the content of total polyphenols and antioxidant potential of Tokaj essence from the years 1999, 2006, 2007, 2009, 2013, 2015. Tokaj essence is produced by fermentation of concentrated must from botrytised grape berries. The highest content of polyphenols was determined in the essence of 1999 (275.8 ±18.17 mg.L-1) and the lowest in the sample of 2015 (118.8 ±12.28 mg.L-1). Antioxidant activity was determined by two methods DPPH and PRAC (permanganate reducing antioxidant capacity). Antioxidant DPPH method showed that the essence of year 1999 had significantly the highest activity (63.4 ±0.81 µmol.L-1 Trolox) while essence of year 2015 (47.5 ±1.58 µmol.L-1 Trolox) featured the lowest activity. The results of method PRAC, which determine the total reducing capacity of the essence, do not correlate with the results of DPPH and total phenolic content, because of higher content of saccharides, which gave false positive test results. The method PRAC is not suitable for measuring antioxidant activity of tokaj esence. The results showed that aging of wine increased the content of polyphenols and also its antioxidant activity. High content of polyphenols and the great antioxidant activity of Tokaj wine receive their beneficial effect to human health

    In Situ Gel with Silver Nanoparticles Prepared Using Agrimonia eupatoria L. Shows Antibacterial Activity

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    Silver nanoparticles (Ag NPs) with antibacterial activity can be prepared in different ways. In our case, we used ecological green synthesis with Agrimonia eupatoria L. The plant extract was used with Ag NPs for the first time to prepare termosensitive in situ gels (ISGs). Such gels are used to heal human or animal skin and mucous membranes, as they can change from a liquid to solid state after application. Ag NPs were characterized with various techniques (FTIR, TEM, size distribution, zeta potential) and their antibacterial activity was tested against Staphylococcus aureus and Escherichia coli. In accordance with the TEM data, we prepared monodispersed spherical Ag NPs with an average size of about 20 nm. Organic active compounds from Agrimonia eupatoria L. were found on their surfaces using FTIR spectroscopy. Surprisingly, only the in situ gel with Ag NPs showed antibacterial activity against Escherichia coli, while Ag NPs alone did not. Ag NPs prepared via green synthesis using plants with medicinal properties and incorporated into ISGs have great potential for wound healing due to the antibacterial activity of Ag NPs and the dermatological activity of organic substances from plants

    In Situ Gel with Silver Nanoparticles Prepared Using <i>Agrimonia eupatoria</i> L. Shows Antibacterial Activity

    No full text
    Silver nanoparticles (Ag NPs) with antibacterial activity can be prepared in different ways. In our case, we used ecological green synthesis with Agrimonia eupatoria L. The plant extract was used with Ag NPs for the first time to prepare termosensitive in situ gels (ISGs). Such gels are used to heal human or animal skin and mucous membranes, as they can change from a liquid to solid state after application. Ag NPs were characterized with various techniques (FTIR, TEM, size distribution, zeta potential) and their antibacterial activity was tested against Staphylococcus aureus and Escherichia coli. In accordance with the TEM data, we prepared monodispersed spherical Ag NPs with an average size of about 20 nm. Organic active compounds from Agrimonia eupatoria L. were found on their surfaces using FTIR spectroscopy. Surprisingly, only the in situ gel with Ag NPs showed antibacterial activity against Escherichia coli, while Ag NPs alone did not. Ag NPs prepared via green synthesis using plants with medicinal properties and incorporated into ISGs have great potential for wound healing due to the antibacterial activity of Ag NPs and the dermatological activity of organic substances from plants

    The Role of Silver Nanoparticles in the Diagnosis and Treatment of Cancer: Are There Any Perspectives for the Future?

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    Cancer is a fatal disease with a complex pathophysiology. Lack of specificity and cytotoxicity, as well as the multidrug resistance of traditional cancer chemotherapy, are the most common limitations that often cause treatment failure. Thus, in recent years, significant efforts have concentrated on the development of a modernistic field called nano-oncology, which provides the possibility of using nanoparticles (NPs) with the aim to detect, target, and treat cancer diseases. In comparison with conventional anticancer strategies, NPs provide a targeted approach, preventing undesirable side effects. What is more, nanoparticle-based drug delivery systems have shown good pharmacokinetics and precise targeting, as well as reduced multidrug resistance. It has been documented that, in cancer cells, NPs promote reactive oxygen species (ROS) production, induce cell cycle arrest and apoptosis, activate ER (endoplasmic reticulum) stress, modulate various signaling pathways, etc. Furthermore, their ability to inhibit tumor growth in vivo has also been documented. In this paper, we have reviewed the role of silver NPs (AgNPs) in cancer nanomedicine, discussing numerous mechanisms by which they render anticancer properties under both in vitro and in vivo conditions, as well as their potential in the diagnosis of cancer

    Mechanochemical Synthesis and Isomerization of N-Substituted Indole-3-carboxaldehyde Oximes †

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    Performing solution-phase oximation reactions with hydroxylamine hydrochloride (NH2OH&middot;HCl) carries significant risk, especially in aqueous solutions. In the present study, four N-substituted indole-3-carboxaldehyde oximes were prepared from the corresponding aldehydes by solvent-free reaction with NH2OH&middot;HCl and a base (NaOH or Na2CO3) using a mechanochemical approach, thus minimizing the possible risk. In all cases, the conversion to oximes was almost complete. The focus of this work is on 1-methoxyindole-3-carboxaldehyde oxime, a key intermediate in the production of indole phytoalexins with useful antimicrobial properties. Under optimized conditions, it was possible to reach almost 95% yield after 20 min of milling. Moreover, for the products containing electron-donating substituents (-CH3, -OCH3), the isomerization from the oxime anti to syn isomer under acidic conditions was discovered. For the 1-methoxy analog, the acidic isomerization of pure isomers in solution resulted in the formation of anti isomer, whereas the prevalence of syn isomer was observed in solid state. From NMR data the syn and anti structures of produced oximes were elucidated. This work shows an interesting and possibly scalable alternative to classical synthesis and underlines environmentally friendly and sustainable character of mechanochemistry

    Antiproliferative Effect of <i>Phellodendron amurense</i> Rupr. Based on Angiogenesis

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    Phellodendron amurense Rupr. is medicinal plant used for supplemental therapy of various diseases based on their positive biological activities. The aim of this study was evaluated the main metabolite, safety of application and anticancer potential. Berberine was determined by HPLC as main alkaloid. Harmful character was determined by irritation test in ovo. The potential cancerogenic effect was studied in vitro on a cellular level, in ovo by CAM assay and in vivo on whole organism Artemia franciscana. Extract from the bark of Phellodendron amurense showed antiproliferative and antiangiogenic effects. The results of our work showed promising anticancer effects based also on the inhibition of angiogenesis with minimum negative effects

    β-Escin Effectively Modulates HUVECs Proliferation and Tube Formation

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    In the present study we evaluated the anti-angiogenic activities of β-escin (the major active compound of Aesculus hippocastanum L. seeds). Human umbilical-vein endothelial cells (HUVECs) were used as an in vitro model for studying the molecular mechanism underlying the anti-angiogenic effect of β-escin. We investigated the in vitro effects on proliferation, migration, and tube formation of HUVECs and in vivo anti-angiogenic activity was evaluated in a chick chorioallantoic membrane (CAM) angiogenesis assay. Moreover, the effect on gene expressions was determined by the RT2 ProfilerTM human angiogenesis PCR Array. It was found that β-escin exerts inhibitory effect on the basic fibroblast growth factor (bFGF)-induced proliferation, migration and tube formation, as well as CAM angiogenesis in vivo. The inhibition of critical steps of angiogenic process observed with β-escin could be partially explained by suppression of Akt activation in response to bFGF. Moreover, the anti-angiogenic effects of β-escin could also be mediated via inhibition of EFNB2 and FGF-1 gene expressions in endothelial cells. In conclusion, β-escin affects endothelial cells as a negative mediator of angiogenesis in vitro and in vivo and may therefore be considered as a promising candidate for further research elucidating its underlying mechanism of action
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