Chemical analysis of Greek pollen - Antioxidant, antimicrobial and proteasome activation properties

<p>Abstract</p> <p>Background</p> <p>Pollen is a bee-product known for its medical properties from ancient times. In our days is increasingly used as health food supplement and especially as a tonic primarily with appeal to the elderly to ameliorate the effects of ageing. In order to evaluate the chemical composition and the biological activity of Greek pollen which has never been studied before, one sample with identified botanical origin from sixteen different common plant taxa of Greece has been evaluated.</p> <p>Results</p> <p>Three different extracts of the studied sample of Greek pollen, have been tested, in whether could induce proteasome activities in human fibroblasts. The water extract was found to induce a highly proteasome activity, showing interesting antioxidant properties. Due to this activity the aqueous extract was further subjected to chemical analysis and seven flavonoids have been isolated and identified by modern spectral means. From the methanolic extract, sugars, lipid acids, phenolic acids and their esters have been also identified, which mainly participate to the biosynthetic pathway of pollen phenolics. The total phenolics were estimated with the Folin-Ciocalteau reagent and the total antioxidant activity was determined by the DPPH method while the extracts and the isolated compounds were also tested for their antimicrobial activity by the dilution technique.</p> <p>Conclusions</p> <p>The Greek pollen is rich in flavonoids and phenolic acids which indicate the observed free radical scavenging activity, the effects of pollen on human fibroblasts and the interesting antimicrobial profile.</p

Artificial intelligence in visible light positioning for indoor IoT : a methodological review

Indoor communication and positioning are significant fields of applications for indoor Internet of Things (IoT) given the rapid growth of IoT in smart cities, smart grids, and smart industries. Visible light positioning (VLP) has become more and more attractive for researchers to provide indoor location-aware IoT services. Additionally, artificial intelligence (AI) has attracted considerable research effort to address the challenges in visible-light communication (VLC) systems. This is an emerging technology in next-generation wireless networks. However, despite the rapid progress, the use of AI in localization, navigation, and position estimation is still underexplored in VLC systems, and various research challenges are still open. This methodological review summarizes the research efforts regarding the use of AI in the field of VLP, to improve the position estimation accuracy in both two-dimensional (2D) and three-dimensional (3D) indoor IoT applications. This treatise also presents open issues and potential future directions for motivating further research in the field. Various databases were utilized in this paper: Scopus, Google Scholar, and IEEE Xplore; obtained 88 papers from 2017 to early 2023. Most (68%) of the AI articles in VLP systems are machine learning (ML) methods applied for localization and position estimation in VLC systems, while the other 32% of the research articles focussed on evolutionary algorithms. ML and evolutionary models may present limitations in terms of complexity and time-consuming nature but offer highly accurate, robust, reliable, and cost-effective results in terms of position estimation over conventional approaches

A Randomized Controlled Trial on Pleurotus eryngii Mushrooms with Antioxidant Compounds and Vitamin D2 in Managing Metabolic Disorders

This study examined the effects of a Pleurotus eryngii mushroom snack on metabolically unhealthy patients. After harvest, mushrooms were baked and subjected to UV-B irradiation to enhance vitamin D2 content. A randomized controlled trial was conducted for three months with two arms. Both groups received conventional nutritional counseling for metabolic disorders, while the intervention group had to consume the snack daily as well. We collected blood samples at the beginning and the end of the study to determine biochemical measurements and serum 25(OH)D2 and to evaluate inflammation and oxidative stress. One hundred patients consented and were randomized. Comparatively to the control group, snack consumption regulated glucose levels and reduced body weight, fat, waist and hip circumferences. In addition, 25(OH)D2 increased significantly in the intervention group. The levels of LDL and SGOT were lower only in the intervention group. Levels of IL-6 and ox-LDL decreased in the mushroom group, while the overall physical health increased. These findings suggest potential antidiabetic, antiobesity, anti-inflammatory and antioxidant health benefits of the snack to metabolically unhealthy individuals

Hydroxytyrosol encapsulated in biocompatible water-in-oil microemulsions: How the structure affects in vitro absorption

Over the last years, the incorporation of natural antioxidants in food and pharmaceutical formulations has gained attention, delaying or preventing oxidation phenomena in the final products. In order to take full advantage of their properties, protection in special microenvironments is of great importance. The unique features of the natural phenolic compound hydroxytyrosol (HT) - including antioxidant, anti-inflammatory, antiproliferative and cardioprotective properties - have been studied to clarify its mechanism of action. In the present study novel biocompatible water-in-oil (W/O) microemulsions were developed as hosts for HT and subsequently examined for their absorption profile following their oral uptake. The absorption of HT in solution was compared with the encapsulated one in vitro, using a coculture model (Caco-2/TC7 and HT29-MTX cell lines). The systems were structurally characterized by means of Dynamic Light Scattering (DLS) and Electron Paramagnetic Resonance (EPR) techniques. The diameter of the micelles remained unaltered after the incorporation of 678 ppm of HT but the interfacial properties were slightly affected, indicating the involvement of the HT molecules in the surfactant monolayer. EPR was used towards a lipophilic stable free radial, namely galvinoxyl, indicating a high scavenging activity of the systems and encapsulated HT. Finally, after the biocompatibility study of the microemulsions the intestinal absorption of the encapsulated HT was compared with its aqueous solution in vitro. The higher the surfactants' concentration in the system the lower the HT concentration that penetrated the constructed epithelium, indicating the involvement of the amphiphiles in the antioxidant's absorption and its entrapment in the mucus layer