Publications by authors named "Kristina Radic"

Astaxanthin (ASTA) and zeaxanthin (ZEA) are xanthophyll carotenoids showing a wide spectrum of health-promoting properties. However, their utilization is limited, mostly due to poor water solubility, limited bioavailability, and a tendency to oxidate, as well as photo- and thermal instability. The aim of this work was to develop ASTA- and ZEA-loaded nano-structured lipid carriers (NLCs) that would protect them against degradation and improve their intestinal stability/permeability.

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Selenium nanoparticles (SeNPs) represent novel selenium (Se) formulation characterized by improved biocompatibility and a wider therapeutic range in comparison to inorganic Se. The aim of this work was to investigate the possibilities of functionalization of SeNPs with olive pomace extract (OPE), rich in health-promoting polyphenols, and to obtain innovative forms of nutraceuticals. Cytotoxic and antioxidative activities of four types of SeNPs (polyvinylpyrrolidone stabilized (PVP SeNPs), polysorbate stabilized (PS SeNPs), polyvinylpyrrolidone stabilized and functionalized using OPE (f PVP SeNPs) and polysorbate stabilized and functionalized using OPE (f PS SeNPs) were investigated.

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Limited scientific evidence shows that alpha lipoic acid (ALA) can induce regression rates of low-grade squamous intraepithelial lesions (LSILs), but the mechanisms of these effects have not been elucidated. To gain a broader insight into its therapeutic potential and mechanisms of action, the effects of 3 months of supplementation with 600 mg of ALA on antioxidant and lipid status parameters in 100 patients with LSILs were investigated in a randomized, placebo-controlled study. The obtained results are discussed in terms of patients' initial metabolic status and diet quality (particularly nutritional intake of antioxidants).

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Raw and purified mandarin peel-derived pectins were characterized and combined with olive pomace extract (OPE) in the green synthesis of selenium nanoparticles (SeNPs). SeNPs were characterized in terms of size distribution and zeta potential, and their stability was monitored during 30 days of storage. HepG2 and Caco-2 cell models were used for the assessment of biocompatibility, while antioxidant activity was investigated by the combination of chemical and cellular-based assays.

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Low-grade squamous intraepithelial lesion (SIL) is a cytologic diagnosis etiologically related to human papilloma virus (HPV) infection that leads to the release of inflammation mediators, the formation of reactive oxygen species (ROS) and decreased levels of antioxidants in tissues, which is why antioxidants might be considered effective against SIL progression. This randomized double-blind placebo-controlled study aimed to investigate the effectiveness of alpha-lipoic acid (ALA) supplementation (600 mg/day) on the regression of low-grade SIL in 100 patients. Low-grade SIL was determined after the cytological screening, colposcopic examination and targeted biopsy and histological confirmation of cytological−colposcopic diagnosis.

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Olive pomace extract (OPE) was investigated as a potential surface modifier for the development of the green synthesis process of selenium nanoparticles (SeNPs). In order to evaluate them as potential nutraceuticals, the obtained nanosystems were characterized in terms of size distribution, shape, zeta potential, stability in different media, gastrointestinal bioaccessibility and biocompatibility. Systems with a unimodal size distribution of spherical particles were obtained, with average diameters ranging from 53.

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Background: olive pomace extract (OPE) is a rich source of health promoting polyphenols (hydroxytyrosol (HTS) and tyrosol (TS)) and can be used as a nutraceutical ingredient of dietary supplements and functional foods. Its adequate bioavailability is a prerequisite for excreting biological activity and can be significantly and specifically affected by different food matrices.

Methods: in order to investigate food effects on polyphenol bioaccessibility, OPE was co-digested with different foods according to internationally harmonized in vitro digestibility method.

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Olive pomace is a valuable secondary raw material rich in polyphenols, left behind after the production of olive oil. The present study investigated the protective effect of a polyphenolic extract from olive pomace (OPE) on cell viability and antioxidant defense of cultured human HepG2 cells submitted to oxidative stress induced by -butylhydroperoxide (tBOOH). The investigation considered possible matrix effects, impact of gastrointestinal digestion and cyclodextrin (CD) encapsulation.

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Olive pomace is a rich source of biologically active compounds, mainly polyphenols. Recently, an efficient and sustainable cyclodextrin (CD)-enhanced extraction was developed. It enabled a relatively simple formulation of high-quality olive pomace extracts (OPEs) that can be used as alternative sources of olive-derived polyphenols in the nutrition and pharma industries.

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Waste remaining after the production of olive oil (olive pomace) is known to contain significant amounts of phenolic compounds that exert different types of biological activities, primarily acting as antioxidants. In this work, a sustainable approach that combines ultrasound-assisted extraction with food-grade solvents and encapsulation with different types of cyclodextrins was used to prepare olive pomace-based polyphenol rich extracts that were tested as antioxidants in various chemical, food, and biological model systems. Encapsulation with cyclodextrins had a significant positive impact on the chemical composition of obtained extracts and it positively affected their antioxidant activity.

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Here we have collected evidence suggesting that chronic changes in the NO homeostasis and the rise of reactive oxygen species bioavailability can contribute to cell dysfunction in Leber's hereditary optic neuropathy (LHON) patients. We report that peripheral blood mononuclear cells (PBMCs), derived from a female LHON patient with bilateral reduced vision and carrying the pathogenic mutation 11778/ND4, display increased levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS), as revealed by flow cytometry, fluorometric measurements of nitrite/nitrate, and 3-nitrotyrosine immunodetection. Moreover, viability assays with the tetrazolium dye MTT showed that lymphoblasts from the same patient are more sensitive to prolonged NO exposure, leading to cell death.

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