Irena Landeka

University of Zagreb · Faculty of Food Technology and Biotechnology (PBF)

The health benefits of polyphenols are based on their bioavailability, which is why a significant portion of research focuses on factors that affect their bioavailability. Previous studies suggest that the intake of polyphenols along with macronutrients in food represents one of the key factors influencing the bioavailability of polyphenols and, co...

Besides the use of resveratrol as a drug candidate, there are obstacles mainly due to its poor pharmacokinetic properties. Numerous studies are being conducted on the synthesis of resveratrol derivatives that exhibit enhanced biological activity. The aim of our research was to investigate activity of the newly synthesized ferrocene‐containing triac...

Background and purpose: Prunus spinose L. is a traditionally consumed, recently scientifically reexamined plant. Brain bioavailability and functionality of polyphenols (PPH) of blackthorn flower extract (PSE) was investigated.Materials and methods: C57BL/6 mice received oral daily repeated doses of 25 mg/kg body weight of total PSE polyphenols for...

The aim of this study was to evaluate how nettle (Urtica dioica L.) water extract consumption would interact with regulators of peroxysomal lipid oxidation, histone deacetylase, and markers of oxidative stress in the liver and blood lipid levels in male and female C57Bl6 mice. Metabolically unchallenged (healthy) mice (n = 5 per sex) were treated w...

Valproate is a common antiepileptic drug whose adverse effects include liver steatosis and dyslipidaemia. The aim of our study was to see how natural flavonoid antioxidant naringin would interact with valproate and attenuate these adverse effects. For this reason we treated male C57BL6 mice with a combination of 150 mg/kg of valproate and 25 mg/kg...

Essential oils (EOs) from aromatic and medicinal plants, such as myrtle (Myrtus communis L.) and Laurel (Laurus nobilis L.), are gaining popularity as a potential ingredient in functional foods and nutraceuticals. This study aims to investigate whether the essential oils (EOs) could be effective in weight control, antioxidative and antilipidemic st...

Polyphenols of Laurel and Myrtle exhibit structural diversity, which affects bioavailability, metabolism, and bioactivity. The gut microbiota plays a key role in modulating the production, bioavailability and, thus the biological activities of phenolic metabolites, particularly after the intake of food containing high-molecular-weight polyphenols....

Research background: The use of plants and their extracts in treatments of chronic diseases is widely known in traditional medicine. The aim of this study is to determine the effects of 10-day consumption of blackthorn (Prunus spinosa L.) flower extract on blood glucose, glycaemic load, serum α-amlyase activity and insulin concentration in normogl...

The study examined the antioxidative physiological effects of phenolics from an ethanol-water extract of blackthorn flowers orally administrated to C57/BL6 mice for 28 days in daily doses of 25 mg of total phenolics/kg body weight. Contents of phenolics in the intestine, liver, and kidneys collected after 1, 7, 14, 21, and 28 days of extract admini...

Reports in the recent literature indicate that consumption of phytochemicals (e.g. plant polyphenols) has been associated with a wide range of health benefits. Fennel ( Foeniculum vulgare Mill.) is common Mediterranean plant that has been widely used as medicinal and aromatic herb. Numerous studies reported the use of fennel extracts (plant or seed...

Prunus spinosa L. (blackthorn) is used in traditional medicine as a remedy for various diseases. To establish its anticancer properties, we exposed human liver cancer cells (Hep G2) to a range of blackthorn flower extract concentrations (10-200 μg/mL) and determined cytotoxic activity with the neutral red and kenacid blue methods after 24, 48, and...

Prunus spinosa L. (blackthorn) flower was most recently pointed out as a valuable source of bioactive compounds that have potent anticancer properties. To test for antineoplastic activity, hepatocarcinoma cells (Hepa 1–6) and corresponding non-neoplastic hepatocytes (AML 12) were subjected to Prunus spinosa L. blossom ethanolic extract (5–200 μg mL...

Obesity, a major health problem worldwide, is associated with increased cardiovascular risk factors, such as dyslipidemia, glucose intolerance, and hypertension. We investigated the antioxidative capacity of the ethanol extract of propolis (EEP) and its effect on the lipid profile, the hepatorenal function, and the atherogenic indices in mice fed w...

Obesity, a major health problem worldwide, is associated with increased cardiovascular risk factors, such as dyslipidemia, glucose intolerance, and hypertension. We investigated the antioxidative capacity of the ethanol extract of propolis (EEP) and its effect on the lipid profile, the hepatorenal function, and the atherogenic indices in mice fed w...

Obesity, major health problem worldwide, is associated with the increased cardiovascular risk factors such as dyslipidemia, glucose intolerance and hypertension. We investigated antioxidative capacity of ethanol extract of propolis (EEP) and its effect on lipid profile, hepatorenal function, and atherogenic indices in mice fed with high-fat diet (H...

The goal of this study was to analyse the fatty acid (FA) profiles of the streaked (starry) weever (Trachinus radiatus), a prized food fish in the countries of its distribution. Fish (N = 20) were sampled in July 2011. Location: 42.761019°N, 17.765090°W; Adriatic Sea, Elaphite Islands near Dubrovnik, Croatia, at 5–10 m depth using longline hooks; b...

Background. The current topics in fish fatty acid (FA) research include qualitative comparisons, trophic transfer as nutritive sources of FA, evolutionary comparison of synthesis pathways, and potential application of most efficient fish desaturases and elongases. FA are scarcely investigated in Elopomorpha and Anguilliformes, except for common-and...

The study examines the potential of wine industry by-product, the lees, as a rich mixture of natural polyphenols, and its physiological potential to reduce postprandial metabolic and oxidative stress caused by a cholesterol-rich diet in in vivo model. Chemical analysis of wine lees showed that their total solid content was 94.2%. Wine lees containe...

The study examines the potential of wine industry by-product, the lees, as a rich mixture of natural polyphenols, and its physiological potential to reduce postprandial metabolic and oxidative stress caused by a cholesterol-rich diet in in vivo model. Chemical analysis of wine lees showed that their total solid content was 94.2 %. Wine lees contain...

Chokeberries are a subject of numerous studies due to a high phenolic compound content, antioxidant properties and potential positive influence on the health. Effects of weather conditions on fruit quality attributes, phenolic compounds and antioxidant capacity of chokeberry (Aronia melanocarpa) juice over three consecutive years were investigated....

In diabetes, an impaired antioxidant defense system contributes to the development of diabetic retinopathy. The main objective of this paper was to find correlations of oxidative stress parameters within and between the vitreous and serum in patients with type 2 diabetes who had developed proliferative diabetic retinopathy. The study included and c...

Chokeberries (Aronia melanocarpa) are rarely used in diet in Croatia but they have high content of polyphenolic compounds and one of the highest in vitro antioxidant activities among fruits. The aim of this study is to compare the quality, phenolic content and antioxidant capacity of different chokeberry products (juices, powders, fruit tea, capsul...

Obesity has become one of the major threats for public health in industrialised world among adults, but also among adolescents and children. It is infl uenced by the interaction of genes, nutrition, environment, and lifestyle. Environmental and lifestyle risk factors include foetal and lifelong environment, nutrient quality, chemical and microbial...

Obesity has become one of the major threats for public health in industrialised world among adults, but also among adolescents and children. It is influenced by the interaction of genes, nutrition, environment, and lifestyle. Environmental and lifestyle risk factors include foetal and lifelong environment, nutrient quality, chemical and microbial e...

Imazalil, cypermethrin and carbendazim are detected in plants for human nutrition. To explore whether their combinations, applied orally in low doses, would induce changes in metabolic patterns and hepatotoxicity, a subchronic in vivo experiment was conducted. Doses of 10mg/kg of imazalil (im) and cypermethrin (cy) and 20 mg/kg of carbendazim (car)...

Low-fat diets increase serum triacilglycerol and decrease HDL-cholesterol concentrations, thereby potentially adversely affecting cardiovascular disease (CVD) risk. The present study compared the CVD risk profi le of a high-MUFA diets (olive oil) and high-PUFA diets (pumpkin seed oil). The most significant difference between the two groups was that...

The ability of aminoacyl-tRNA synthetases to distinguish between similar amino acids is crucial for accurate translation of the genetic code. Saccharomyces cerevisiae seryl-tRNA synthetase (SerRS) employs tRNA-dependent recognition of its cognate amino acid serine [Lenhard, B., Filipic, S., Landeka, I., Skrtic, I., Söll, D. & Weygand-Durasevic, I....

The high level of translational fidelity is ensured by various types of quality control mechanisms, which are adapted to prevent or correct naturally occurring mistakes. Accu-rate aminoacyl-tRNA synthesis is mostly dependent on the specificity of the aminoacyl--tRNA synthetases (aaRS), i.e. their ability to choose among competing structurally simil...

The interaction of Saccharomyces cerevisiae seryl-tRNA synthetase (SerRS) with peroxin Pex21p was identified in a two-hybrid screen with SerRS as bait. This was confirmed by an in vitro binding assay with truncated Pex21p fused to glutathione S-transferase. Furthermore, purified Pex21p acts as an activator of yeast seryl-tRNA synthetase in aminoacy...

In our study of seryl-tRNA formation in maize, we investigated the enzymes involved in serylation. Only two dissimilar seryl-tRNA synthetase (SerRS) cDNA clones were identified in the Zea mays EST (expressed sequence tag) databases. One encodes a seryl-tRNA synthetase, which presumably functions in the organelles (SerZMm), while the other synthetas...

The involvement of amino acids within the motif 2 loop of Saccharomyces cerevisiae seryl-tRNA synthetase (SerRS) in serine and ATP binding was demonstrated previously [B. Lenhard et al., J. Biol. Chem. 272 (1997) 1136–1141]. In our attempt to analyze the structural basis for the substrate specificity and to explore further the catalytic mechanism e...

The involvement of amino acids within the motif 2 loop of Saccharomyces cerevisiae seryl-tRNA synthetase (SerRS) in serine and ATP binding was demonstrated previously [B. Lenhard et al., J. Biol. Chem. 272 (1997) 1136^1141]. In our attempt to analyze the structural basis for the substrate specificity and to explore further the catalytic mechanism e...

For acyclic molecules, Randić4 introduced a family of topological indices, the path numbers mZ, m = 1, 2,..., which are deduced from the Hosoya matrix. The path-number concept was recently extended to molecules containing cycles. Relations between 1Z, 2Z and the Hosoya index Z were established. 6 In this work we point out several further relations...

The active site of class II aminoacyl-tRNA synthetases contains the motif 2 loop, which is involved in binding of ATP, amino acid, and the acceptor end of tRNA. In order to characterize the active site of Saccharomyces cerevisiae seryl-tRNA synthetase (SerRS), we performed in vitro mutagenesis of the portion of the SES1 gene encoding the motif 2 lo...

It is shown analytically that the recently introduced P'/P index and the Wiener number are closely related graph-theoretical invariants for connected undirected acyclic structures and cycles.

The path numbers of the mth order, mZ, of a connected undirected graph are introduced and studied analitically. The definition of the 1Z and 2Z indices for acyclic graphs proposed earlier is generalized in order to cover cyclic graphs. The relationships between the path numbers 1Z and 2Z and the Hosoya Z index are discussed. It is shown that the pa...