High-throughput synchronous erythrocyte cellular antioxidant activity and protection screening of phenolic-rich extracts: Protocol validation and applications.

Oxidative/nitrosative damage takes part in chronic disease development, which generates an urgent need for intervention and better therapies to manage them. The scientific community has demanded easy-to-run, cheap, and reliable methods for cellular antioxidant activity assays. This work standardised and validated an erythrocyte cellular antioxidant activity and membrane protection/injury (HERYCA-P) protocol to study food-derive extracts. The method measures intracellular reactive oxygen species (ROS) generation, lipoperoxidation, and haemolysis induced by 2,2'-azobis(2-amidinopropane) dihydrochloride. Quercetin decreased ROS generation by 50.4% and haemolysis by 2.2%, while ascorbic acid inhibited lipid peroxidation by 40.1%. Total phenolic contents of teas were correlated with decreased ROS generation (r = -0.924), lipoperoxidation (r = -0.951), and haemolysis (r = -0.869). The erythrocyte ROS generation and lipoperoxidation were also associated with CUPRAC (r = -0.925; r = -0.951) and hydroxyl radical scavenging activity (r = -0.936; r = -0.949). The precision rates of antioxidant standards and tea samples were below 15%. HERYCA-P is feasible as a complementary antioxidant assay for food matrices.

Toxicological and bioactivity evaluation of blackcurrant press cake, sea buckthorn leaves and bark from Scots pine and Norway spruce extracts under a green integrated approach.

Aqueous extracts from blackcurrant press cake (BC), Norway spruce bark (NS), Scots pine bark (SP), and sea buckthorn leaves (SB) were obtained using maceration and pressurized hot water and tested for their bioactivities. Maceration provided the extraction of higher dry matter contents, including total phenolics (TPC), anthocyanins, and condensed tannins, which also impacted higher antioxidant activity. NS and SB extracts presented the highest mean values of TPC and antioxidant activity. Individually, NS extract presented high contents of proanthocyanidins, resveratrol, and some phenolic acids. In contrast, SB contained a high concentration of ellagitannins, ellagic acid, and quercetin, explaining the antioxidant activity and antibacterial effects. SP and BC extracts had the lowest TPC and antioxidant activity. However, BC had strong antiviral efficacy, whereas SP can be considered a potential ingredient to inhibit α-amylase. Except for BC, the other extracts decreased reactive oxygen species (ROS) generation in HCT8 and A549 cells. Extracts did not inhibit the production of TNF-alpha in lipopolysaccharide-stimulated THP-1 macrophages but inhibited the ROS generation during the THP-1 cell respiratory burst. The recovery of antioxidant compounds from these by-products is incentivized for high value-added applications.