Recovery of phytochemical from three safflower (Carthamus tinctorius L.) by-products: Antioxidant properties, protective effect of human erythrocytes and profile by UPLC-DAD-MS

Agro-industrial by-products are an important source of phenolic compounds. In this study was to evaluate the antioxidant capacity, the protective effect on human erythrocytes and to identify the phenolic compounds present in of safflower (Carthamus tinctorius L.) by-product by UPLC-DAD-MS. The highest antioxidant activity was for leaf methanolic extract by 2,2-diphenyl-1-picrylhydrazyl (DPPH^●) (IC₅₀ 9.65 µg/ml) and ABTS^●+ (IC₅₀ 8.46 µg/ml) methods. The stem of both methanolic and ethanolic extracts presented the best protection effect on human erythrocytes (91.86 ± 0.72% and 87.55 ± 0.61%, respectively). Total phenols (6.44 ± 0.18 mg gallic acid equivalent/g) and flavonoids (11.22 ± 0.023 mg quercetin equivalent /g) were higher in leaf followed by mixture (stem + leaf) and stem in methanolic and ethanolic extracts. The major compounds identified by UPLC-DAD-MS were luteolin 7-O-β-D-glucoside, quercetin-3-galactoside, and hydroxysafflor yellow A. Therefore, safflower by-products are sources of obtaining phenolic compounds with application in the food or pharmaceutical areas. Novelty impact statement: Safflower (Carthamus tinctorius L.) by-products are important resources of phenolic compounds with high antioxidant activity (ABTS^●+, IC₅₀ = 8.46 µg/ml) and high protective effect on human erythrocytes.