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Iron oxide nanoparticles (IONPs) have many practical applications, ranging from environmental protection to biomedicine. IONPs are being investigated due to their high potential for antimicrobial activity and lack of toxicity to humans. However, the biological activity of IONPs is not uniform and depends on the synthesis conditions, which affect the shape, size and surface modification. The aim of this work is to synthesise IONPs using a mixed method, i.e., chemical co-precipitation combined with biogenic surface modification, using extracts from spent hops (Humulus lupulus L.) obtained as waste product from supercritical carbon dioxide hop extraction. Different extracts (water, dimethyl sulfoxide (DMSO), 80% ethanol, acetone, water) were further evaluated for antioxidant activity based on the silver nanoparticle antioxidant capacity (SNPAC), total phenolic content (TPC) and total flavonoid content (TFC). The IONPs were characterised via UV-vis spectroscopy, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and Fourier-transform infrared (FT-IR) spectroscopy. Spent hop extracts showed a high number of flavonoid compounds. The efficiency of the solvents used for the extraction can be classified as follows: DMSO > 80% ethanol > acetone > water. FT-IR/ATR spectra revealed the involvement of flavonoids such as xanthohumol and/or isoxanthohumol, bitter acids (i.e., humulones, lupulones) and proteins in the surface modification of the IONPs. SEM images showed a granular, spherical structure of the IONPs with diameters ranging from 81.16 to 142.5 nm. Surface modification with extracts generally weakened the activity of the IONPs against the tested Gram-positive and Gram-negative bacteria and yeasts by half. Only the modification of IONPs with DMSO extract improved their antibacterial properties against Gram-positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Micrococcus luteus, Enterococcus faecalis, Bacillus cereus) from a MIC value of 2.5–10 mg/mL to 0.313–1.25 mg/mL. [ABSTRACT FROM AUTHOR]

Iron oxide nanoparticles (IONPs) have many practical applications, ranging from environmental protection to biomedicine. IONPs are being investigated due to their high potential for antimicrobial activity and lack of toxicity to humans. However, the biological activity of IONPs is not uniform and depends on the synthesis conditions, which affect the shape, size and surface modification. The aim of this work is to synthesise IONPs using a mixed method, i.e., chemical co-precipitation combined with biogenic surface modification, using extracts from spent hops (Humulus lupulus L.) obtained as waste product from supercritical carbon dioxide hop extraction. Different extracts (water, dimethyl sulfoxide (DMSO), 80% ethanol, acetone, water) were further evaluated for antioxidant activity based on the silver nanoparticle antioxidant capacity (SNPAC), total phenolic content (TPC) and total flavonoid content (TFC). The IONPs were characterised via UV-vis spectroscopy, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and Fourier-transform infrared (FT-IR) spectroscopy. Spent hop extracts showed a high number of flavonoid compounds. The efficiency of the solvents used for the extraction can be classified as follows: DMSO > 80% ethanol > acetone > water. FT-IR/ATR spectra revealed the involvement of flavonoids such as xanthohumol and/or isoxanthohumol, bitter acids (i.e., humulones, lupulones) and proteins in the surface modification of the IONPs. SEM images showed a granular, spherical structure of the IONPs with diameters ranging from 81.16 to 142.5 nm. Surface modification with extracts generally weakened the activity of the IONPs against the tested Gram-positive and Gram-negative bacteria and yeasts by half. Only the modification of IONPs with DMSO extract improved their antibacterial properties against Gram-positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Micrococcus luteus, Enterococcus faecalis, Bacillus cereus) from a MIC value of 2.5–10 mg/mL to 0.313–1.25 mg/mL.

Spent hop extract (SHE) is hypothesized to possess multifaceted anticoagulant effect and to reduce platelet reactivity in a direct manner and to improve the antiplatelet action of endothelium. The results demonstrated that SHE, rich in flavanols (50% of total phenolic compounds), hydroxycinnamic acids, proanthocyanidin oligomers, flavan-3-ol monomers, and flavonol glycosides, inhibited ADP-induced platelet aggregation up to 11% for 7.5 µg/ml or up to 23% for 15 µg/ml, P

Hop cones (Humulus lupulusL.), very rich source of phenolic compounds, possessing anticancer, antioxidant and anti-inflammatory activities, are considered as beneficial diet ingredients improving human health. In this study, the antiplatelet action of xanthohumol (XN), the principal flavonoid in hop cones, was investigated. XN significantly attenuated ADP-induced blood platelet aggregation (97.2 ± 35.7 AU for 6 μg/ml of XNvs. 120.4 ± 30.1 AU for 0.17% dimethyl sulfoxide (DMSO),p < 0.001) and significantly reduced the expression of fibrinogen receptor (activated form of GPIIbIIIa) on platelets’ surface (47.6 ± 15.8 for 1.5 μg/ml XN, 44.6 ± 17.3% for 3 μg/ml XNvs. 54.5 ± 19.2% for control or 43.3 ± 18.4% for 6 μg/ml XNvs.49.7 ± 19.4% for 0.17% DMSO,p < 0.05 or less). These findings suggest that the phenolic compounds originating from hops (XN) have a novel role as antiplatelet agents and can likely be used as dietary supplements in prophylactic approaches. [ABSTRACT FROM AUTHOR]

Spent hop extract (SHE) is hypothesized to possess multifaceted anticoagulant effect and to reduce platelet reactivity in a direct manner and to improve the antiplatelet action of endothelium. The results demonstrated that SHE, rich in flavanols (50% of total phenolic compounds), hydroxycinnamic acids, proanthocyanidin oligomers, flavan-3-ol monomers, and flavonol glycosides, inhibited ADP-induced platelet aggregation up to 11% for 7.5 µg/ml or up to 23% for 15 µg/ml, P  <   0.05. Additionally, SHE ameliorated anticoagulant activity of human endothelial cells to significantly reduce platelet reactivity. This effect could be related to the increased expression/activity of the ecto-ADPase (CD39). ADP-induced platelet reactivity was reduced in the case of platelets incubated with the extract-treated endothelial cells compared to the untreated cells. Diabetic rats fed with SHE demonstrated longer survival time than the group treated with placebo. In conclusion, our study provided evidence for a potential beneficial role of SHE in the regulation of platelet and endothelial function. [ABSTRACT FROM AUTHOR]