Abstract

In this study, ultrasonic-assisted extraction was used to extract flavonoids from Adiantum capillus-veneris L. The crude flavonoids of Adiantum (FA) were then purified with the AB-8 macroporous adsorption resin. The antioxidant activities of the purified FA were evaluated and compared with synthetic antioxidants in scavenging capability of 1, 1-diphenyl 1-2-picryl-hydrazyl (DPPH) free radical, scavenging capacity of superoxide anion, chelating capability of ferrousion and reducing power in vitro. The antioxidant activities of FA in vivo also were investigated through acute mice liver injury experiment. The results showed that antioxidant activity of FA was relevant to concentration; the antioxidant activities of FA in vitro were approximate or more significant than that of some synthetic antioxidants (butylated hydroxytoluene (BHT), ethylenediaminetetraacetic acid (EDTA) and ascorbic acid). The liver intoxicated by CCl₄ in mice showed a significant decrease in superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels, simultaneously significant increase in the level of malondialdehyde (MDA) (P < 0.01). Compared with the toxic control group that received only CCl4, the group that received vitamin E and higher dose of FA showed significant increase in activity of SOD, CAT and GSH, together with notable decrease in activity of MDA. These changes were in a dose dependent manner. The results showed that the FA possesses potent antioxidant properties, and might be a potential natural source of antioxidants that could be applicable to the medical and food fields.

Key words: Flavonoids, antioxidant, in vitro, in vivo, Adiantum capillus-veneris L.