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Open access

Rastislav Monošík, Miroslav Streďanský and Ernest Šturdík

Biosensors - classification, characterization and new trends

Biosensors represent promising analytical tools applicable in areas such as clinical diagnosis, food industry, environment monitoring and in other fields, where rapid and reliable analyses are needed. Some biosensors were successfully implemented in the commercial sphere, but majority needs to be improved in order to overcome some imperfections. This review covers the basic types, principles, constructions and use of biosensors as well as new trends used for their fabrication.

Open access

Martina Danihelová, Jana Viskupičová and Ernest Šturdík

Lipophilization of flavonoids for their food, therapeutic and cosmetic applications

Flavonoids represent large group of plant pigments. These polyphenolic compounds may be found in the nature as active components of fruits, vegetables and other plants and derived products. Due to established biological effects they are attractive substances for many areas of human life. Many flavonoids are nowadays used in pharmaceutical, cosmetic and food preparations. Their practical applications are in most cases limited by low solubility and stability in lipophilic media. Chemical or enzymatic lipophilization of flavonoid skeleton may not only increase their solubility and stability in lipophilic environment but also their biological properties. This review summarizes current knowledge in this field.

Open access

Ivana Dokupilová, Ernest Šturdík and Daniel Mihálik

Abstract

Nowadays, there are well known PCR-based techniques to detect polymorphism in plants. Marker technologies which are applied in breeding and varietal characterization can be exchanged across laboratories with standardization to yield reproducible results. This article describes applying of simple sequence repeats (SSR) markers in European laboratories, in which the reproducibility of these popular markers are examined. One of the European Union interests is characterization of grape varieties and preparation of International Vitis catalogue for comparison global varieties as Chardonnay, Sauvignon, Pinot noir with the domestic for each other country. Grape genome contains of many SSR, which are highly polymorphic. This review provides the latest information in SSR research including novels in research, comparison, development and application of microsatellites.

Open access

Mária Čarná, Vladimír Repka and Ernest Šturdík

Abstract

To understand the cellular biology and biochemistry of plant cell behavior, there is not only one approach for studying proteins which are directly responsible for cellular activity. However, despite the enormous quantity of information generated by transcriptome analysis, the picture is still incomplete. The proteomic and interactomic approaches present a new point of view that so far has been missing. Comparative proteomics provide a powerful means to study products of genes and their regulation. On the other side, interactomes of different species can provide information about the evolutionary mechanisms leading to organism diversity. Then, this analysis allows scientists to better understand how complex biological processes are regulated and evolved.

Open access

Milada Rakická, Ernest Šturdík and Andrea Marko

Abstract

In current time we can see worldwide rise in number of people suffering from civilization diseases, such as health threatening cardiovascular diseases, obesity, diabetes mellitus, cancer and many others. Cereal products which provide income of important nutritional substance for human health belong among groceries with proven medical effect. Among significant components of cereals with proven effect in prevention of civilization diseases belongs roughage, β-glucans, phytochemicals. Important role also play vitamins and minerals, which are present in cereals in minor values. Article summarizes presence of medically important substances in cereals.

Open access

Martina Danihelová, Miroslav Veverka and Ernest Šturdík

Abstract

Novel quercetin derivatives were prepared to change its physicochemical properties and effects on activity of proteolytic enzymes. For them preparation, the selective protection procedures some of the quercetin hydroxyl groups and acylation of the others with acylchlorides were used. The ability of these compounds to inhibit the activity of serine proteases e.g. trypsin, thrombin, urokinase and elastase was studied. In micromolar range, tested derivatives were the most potent inhibitors of thrombin. There was estimated better inhibition of thrombin for prenylated, acetylated, feruloyl and caffeoyl quercetin esters. Slight inhibitory effect of all quercetin derivatives on elastase was found. Among tested derivatives only diquercetin displayed better inhibiton. Trypsin and urokinase were inhibited by quercetin at comparable level. Slight improvement in inhibitory effect of trypsin and urokinase was seen for chloronaphtoquinone quercetin that revealed enhanced inhibiton of thrombin, too. However, no influence on elastase activity was determined for this compound. Obtained results indicate that certain modifications of quercetin structure could improve its biological properties.

Open access

Daniela Košťálová, Lýdia Bezáková, Lucia Račkovác, Silvia Mošovská and Ernest Šturdík

Abstract

Extensive research over the past half century has shown that curcumin (diferuloylmethane), a polyphenolic compound of turmeric (Curcuma longa L.), can modulate multiple cell signaling pathways. Extensive clinical trials have addressed the pharmacokinetics, safety, and efficacy of this nutraceutical against numerous diseases in human. Curcumin, known for thousand years as a subject of Ayurvedic medicine, has undergone in recent times remarkable transformation into a drug candidate with prospective multipotent therapeutic application. Characterized by high chemical reactivity, resulting from an extended conjugated double bond system prone to nucleophilic attack, curcumin has been shown to interact with a plethora of molecular targets, in numerous experimental observations. In clinical trials, has been used either alone or in combination with other agent. However, its clinical advance has been limited by its short biological half-life, fast metabolism and poor systemic bioavailability after oral administration. To mitigate the above limitations, recently various formulation of curcumin, including nanoparticles, micelles, liposomes, phytosomes delivery system has been examined. The present review has been devoted towards better understanding of the phytonutraceutic properties of curcumin and turmeric based on their disease specific indications and enhancing their prophylactic and therapeutic nutraceutical qualities. The article deals with the biological activity, mode of action, toxicity and forthcoming application of these leads.

Open access

Martina Danihelová, Miroslav Veverka, Ernest Šturdík and Soňa Jantová

ABSTRACT

Quercetin is a natural polyphenol with proven health beneficial activities. In this study 15 new quercetin derivatives were prepared with the aim to enhance their bioavailability. Modification of their physicochemical properties could herewith improve the action in cells. The prepared compounds were tested for their antioxidant and cytotoxic activity. The ability to scavenge free radicals as well as ferric reducing antioxidant power of the new derivatives was not better than that of unmodified quercetin. But for acetylated esters a better cytotoxic activity was found on human cervical cancer cells HeLa than for the initial molecule. The best effect revealed chloronaphtoquinone quercetin (IC50=13.2 μM). For this compound comparable cytotoxic action on non-cancer murine fibroblast cells was detected (IC50=16.5 μM). The obtained results indicate that appropriate lipophilization of the quercetin molecule could improve its cytotoxic action in cells, probably due to its enhanced bioavailability

Open access

Andrea Holubková, Adela Penesová, Ernest Šturdík, Silvia Mošovská and Lucia Mikušová

Abstract

Metabolic syndrome represents a clustering of risk factors related to an elevated danger of cardiovascular diseases and type 2. diabetes. The high incidence of obesity, the key risk factor in metabolic syndrome, and the lack of safe pharmaceutical agents have fuelled an increase in research related to anti-metabolic syndrome drugs. Phytochemicals have biological properties such as antioxidant, modulation of detoxification enzymes, stimulation of the immune system, reduction of platelet aggregation and modulation of hormone metabolism. These compounds include vitamins, comprising of vitamin C, D and E, flavonoids, phenolic acids, omega-3 and omega-6 fatty acids. Furthermore, the latest discoveries and studies on the molecular mechanism of these phytochemicals suggested their potential positive effect in the prevention and treatment of obesity and other risk factors associated with the metabolic syndrome. They should be incorporated in food ingredients, dietary supplements, or drug preparations. The main focus of this article is to review the available information on various aspects of phytochemicals, with special reference to their effectiveness in risk reduction of the metabolic syndrome and obesity-related diseases.

Open access

Michaela Havrlentová, Zuzana Petruláková, Alena Burgárová, Soňa Gavurníková, Viera Červená, Ernest Šturdík, Ján Kraic and Alžbeta Žofajová

Microbiological and sensory evaluations of bread and ketchup supplemented with β-D-glucan hydrogels isolated from wheat, oat, barley, and rye were carried out. Adding hydrocolloids did not affect sensory parameters of bread negatively; moreover rye and oat β-D-glucans improved the total tastiness of bread. Water activity values in fortified breads showed β-D-glucans, except isolated from oat, as elements moderately increasing this parameter and subsequently increasing also bread freshness during the storage. All β-D-glucans resulted in softening the acidic taste of ketchup and did not negatively influence the total tastiness. Quality of fortified fresh tomato ketchups and stored for 180 days, were also not negatively influenced by the addition of hydrocolloids. Therefore, cereal hydrocolloids could be very perspective in the further exploitation in preparing new health-beneficial foods.