Antioxidant and enzyme inhibition activities of Spartium junceum with HPLC-DAD profiling

Spartium junceum L., a Fabaceae plant, is commonly known as Spanish broom and cultivated in the Mediterranean regions. This study aims to investigate the chemical profile, antioxidant and different enzyme inhibitory activities of methanol, ethanol and aqueous extracts obtained from flowers and stems of S. junceum. Also, the phenolic composition was analyzed by HPLC-DAD. Aqueous extract of stems showed the highest (63.94 mg GAE/g) phenolic content, while aqueous extract of stems contained the highest (61.33 mg QE/g) flavonoid content. The stem water extract demonstrated highest DPPH radical scavenging (IC50: 2327 µg/mL) activity, while stem water extract exhibited strong ABTS radical scavenging activity (IC50: 91.80 ± 0.90 µg/mL). The tested extracts differ greatly in terms of enzyme inhibition activity. The stem water extract showed highest Anti-acetylcholinesterase activity (IC50: 46.69 ± 1.66 µg/mL), however stem methanol extract exhibited strong anti-butyrylcholinesterase activity (IC50: 76.39 ± 0.27 µg/mL). The flower methanol extract was most active against α-glucosidase (IC50: 296.7 ± 3.77 µg/mL) enzyme. All extracts showed the least activity against α-amylase and tyrosinase enzymes. When the biological activity results are evaluated, it provides the evidence for the bioactivity-guided isolation studies on the active extracts of this plant.