Antioxidant activity of different polar parts of Salix caprea flower extract

This study evaluated the chemical composition and antioxidant activity of Salix caprea flower extract. The extract was divided into five different fractions using liquid-liquid extraction with petroleum ether (PEF), chloroform (CF), ethyl acetate (EAF), n-butanol (NF) and water (WR). The chemical constituents of the extracts were analyzed via gas chromatography-mass spectrometry. The quantification of total polyphenols and flavonoids was carried out using the Folin-Ciocalteu reagent and various colorimetric techniques. The antioxidant capacity of these fractions was tested by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity assay, 3-ethylbenzthiazoline-6-sulfonic acid radical cation (ABTS⁺) scavenging activity assay and other methods. A total of 153 volatile substances were identified. The highest total polyphenol (40.02 mg/g) and flavonoid (78.62 mg/g) contents were in the EAF. EAF, NF and WR extracts demonstrates significant radical scavenging abilities against four types of free radicals, namely DPPH, ABTS, hydroxyl and super oxide anion. Additionally, it exhibits strong reducing power towards Fe³⁺.. These fractions improved cell viability, reduced malondialdehyde (MDA) and reactive oxygen species (ROS) levels and increased catalase (CAT) and super oxide dismutase (SOD) activity in WRL-68 cells. The study highlights Salix caprea flower extract, particularly its n-butanol fraction, as a potential natural antioxidant source.