Antioxidant Activities of Aqueous Extract from Agrimonia pilosa LEDEB and Its Fractions

Agrimonia pilosa LEDEB is used as the tonic for asthenia and fatigue in China. Considering that the energizing effect might be correlated with antioxidant properties, we investigated the antioxidant activities of aqueous extract (AE) from Agrimonia pilosa LEDEB by assessing radical-scavenging and anti-lipid-peroxidation abilities. We found that AE shows a moderate antioxidant activity to scavenge DPPH center dot, O-2(-center dot), and (OH)-O-center dot and inhibit beta-carotene bleaching with IC50 values of 13.0, 33.2, 351, and 11.9 mu g/ml, respectively, while its AcOEt-soluble fraction (ESF) and BuOH soluble fraction (BSF) exhibit remarkable efficiencies. The ESF's IC50 values of scavenging DPPH center dot, O-2(-center dot), and (OH)-O-center dot, and inhibiting beta-carotene bleaching are 5.6, 5.8, 171, and 7.6 mu g/ml, respectively, and those of BSF are 7.5, 8.4, 82.0, and 6.2 mu g/ml, respectively. In addition, we found that there is a significant correlation between total phenol content and the antioxidant activity determined by O-2(-center dot) and (OH)-O-center dot scavenging, and beta-carotene-bleaching assays. Furthermore, HPLC analysis revealed the presence of quercetin, hyperoside, quercitrin, taxifoliol, luteolin-7-O-beta-D-glucopyranoside, and rutin in Agrimonia pilosa LEDEB. Thus, we suggest that the extracts from Agrimonia pilosa LEDEB, could be considered as natural antioxidant sources and dietary nutritional supplements to prevent oxidation-related diseases.