Chemical and antioxidant studies on Crataegus pentagyna leaves and flowers

The aim of this study was to investigate the antioxidant potential of Crataegus pentagyna leaves and flowers in relation to the phenolic content. The total phenolic, flavonoid and proanthocyanidin contents were determined using Folin-Ciocalteu, aluminium chloride and acid butanol assays, respectively. The radical scavenging activity was evaluated by several in vitro assays: Trolox equivalent antioxidant capacity assay, superoxide anion and hydroxyl radicals scavenging assays. In addition, ferrous ion chelating activity and 15-lipoxygenase inhibition were also investigated. Both leaf and flower extracts had high total phenolic (206.94 +/- 4.86 and 184.62 +/- 1.71 mg/g, respectively), flavonoid (57.08 +/- 0.21 and 67.04 +/- 0.52 mg/g, respectively) and proanthocyanidin contents (68.92 +/- 1.81 and 97.70 +/- 3.81 mg/g, respectively), scavenged ABTS (TEAC=0.64 +/- 0.01 and 0.65 +/- 0.01 mu M Trolox equivalent to 1 mu g/mL extract, respectively), superoxide (EC50=0.9 +/- 0.0 mg/mL) and hydroxyl radicals (EC50=0.9 +/- 0.0 and 0.86 +/- 0.05 mg/mL, respectively), chelated ferrous ions (EC50=1.3 +/- 0.0 and 1.9 +/- 0.0 mg/mL, respectively) and inhibited 15-lipoxygenase (EC50=129.63 +/- 0.75 and 151.76 +/- 1.65 mu g/mL, respectively). It is noteworthy that both extracts showed a higher superoxide anion scavenger activity than catechin (EC50=2.2 +/- 0.0 mg/mL). The results of the study indicate that Crataegus pentagyna leaves and flowers are a promising source of natural antioxidants.