Antioxidant activity of phenolic extracts from different cultivars of Italian onion (Allium cepa) and relative human immune cell proliferative induction

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“…In addition to the provision of nutrients, legumes also contain valuable bioactive compounds such (Huang, Cai, & Zhang, 2010). Studies have focused on the biological activities of phenolic compounds, which have potential antioxidant and free radical scavenging abilities (Lisanti et al, 2016). Investigations on the phenolic composition of legumes have revealed that legumes are good sources of phenolic compounds with antioxidant activities that can be harnessed in the management of free radical related diseases (Attree et al, 2015;Iriti & Varoni, 2017).…”

Bioadhesive Polymeric Films Based on Red Onion Skins Extract for Wound Treatment: An Innovative and Eco-Friendly Formulation

“…The data ranking of the four extracts was perfectly in accordance with TPC results, hypothesizing that TRC is attributable to the polyphenolic component. Again, the extract obtained in abs EtOH at 60 • C was endowed with the best performance also in DPPH assay ( Figure 1C) [18]. The three assays therefore confirmed that the antioxidant component was more soluble in abs EtOH than in hydroalcoholic medium (EtOH 70%) and stable up to 60 • C. Due to the coherence of the obtained data, the extract obtained by using abs EtOH at 60 • C (hereinafter referred as OLE, outside layers extract) was selected for the further studies.…”

“…On the road of biocompatibility, ultrapure water and EtOH were chosen as unique extraction solvents and the procedure was tested both at RT and 60 • C. The obtained results (Table 1) showed that increasing the temperature the recovery yield increased using both abs and 70% EtOH (Table 1); the presence of water in the extraction medium gave a higher extract recovery. TPC of the extracts obtained by the four different procedures was measured by the Folin-Ciocalteu method using a calibration curve of gallic acid standard solutions [18]. The calibration curve was fully validated for intra-day and inter-day precision and accuracy before the use (r = 0.9972).…”

“…Folin-Ciocalteu assay [18] was performed using the sample (extract) dissolved in ultrapure water, whereas in the case of FRAP (ferric ion reducing antioxidant power) and DPPH (2,2-diphenyl -1-picrylhydrazyl) assays [18], the sample was dissolved in EtOH 75%. In any case, the solution was prepared dissolving 20 mg of freeze-dried extract in 50 mL of solvent (0.4 mg/mL).…”

“…Many scientific studies on the lipid-and glucose-lowering [4][5][6][7][8], anti-inflammatory [9][10][11], antioxidant [12][13][14][15][16] and antibacterial [13] properties of onion extracts have been published. Our previous work in this area reported the pungency determination [17] and the antioxidant and immune modulatory activities of purple-skin Rojo Duro onion extracts [18].…”