In vitro and in vivo antioxidant activities of the flavonoid-rich extract from Flos populus.

Flos populi is a well-known traditional Chinese medicine, obtained from the male inflorescence of Populus tomentosa Carr. or Populus canadensis Moench. In this study, we aimed to evaluate the antioxidant activities of Flos populi extract by various in-vitro and in-vivo methods. In-vitro results showed that Flos populi extract had strong antioxidant potential in terms of Superoxide radical and ABTS radical scavenging capacity, nitrogen dioxide radical inhibition and the ability to inhibit lipid peroxidation. Mice were given with Flos populi extract via gavage for 1 month to scrutinize the in-vivo antioxidant effects of Flos populi. The results revealed that Flos populi extract had markedly enhanced the levels of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT), while decreased the level of malondialdehvde (MDA) in serums and livers of mice compared to CCl4 treated group. Additionally, the flavonoids content were determined by the colorimetric method was 553.23 ± 23.45mg/g. The extract was further examined by HPLC and showed the presence of flavonoids-including quercetin (16.26±0.58mg/g), luteolin (9.97±1.07mg/g), apigenin (8.57±0.46mg/g), pinocembrin (119.71±1.05mg/g) and chrysin (16.12±0.53mg/g). The study revealed that Flos populi extract had antioxidant activity and could be utilized as a potential natural antioxidant.