Antioxidant activity of polyphenol and ultrasonic extracts from fruits of Crataegus pentagyna subsp elburensis

The effects of two extracting methods on the total phenolic and total flavonoid contents of Crataegus pentagyna subsp. elburensis Waldst. & Kit. ex Willd fruit extracts were investigated. Antioxidant activities of polyphenol (PP) fraction and ultrasonic (US) extraction were evaluated with four different in vitro antioxidant tests. IC50 for DPPH radical-scavenging activity was 32.2 +/- 1.6 for PP fraction and 36.7 +/- 1.5 mu g mL(-1) for US extract. Reducing powers of extracts increased with the increase of their concentrations. PP fraction exhibited high reducing power at 2-32 mu g mL(-1). Extracts exhibited good H2O2 radical scavenging and Fe2+ chelating ability. Their high phenolic and flavonoid contents could be responsible for their antioxidant activity and pharmacologic actions.