Free Radical Scavenging Activities of the Extracts from Taxus chinensis var. mairei

Under ultrasound, Taxus chinensis var. mairei were extracted with ethanol at 80 degrees C to offer ethanol extract. Ethanol extract was further extracted with chloroform and separated by column chromatography to offer paclitaxel. Their free radical scavenging activity were evaluated and compared with the common antioxidant butylated hydroxytoluene, employing DPPH(center dot)assay, ABTS(+center dot) assay, O-2(center dot-) assay and OH center dot assay. The results showed that ethanol extract exhibited better scavenging activity than the common antioxidant butylated hydroxytoluene in these four assays, with IC50 of 13.19, 2.65, 25.33 and 343.00 mu g/mL, while paclitaxel showed less scavenging activity than butylated hydroxytoluene, with IC50 of 1.49, 46.14, 3.52 and 2.17 mg/mL, respectively. The antioxidant activity screening results demonstrated that ethanol extract displayed better antioxidant activity than that of paclitaxel and the excellent antioxidant activity of ethanol extract may be attributed to other compositions of ethanol extract.