Comparison of anti-xanthine oxidase effects between the water- and ethanol-extracts of the biennial flower. Biennial flower of Panax notoginseng was extracted by water or various concentrations of ethanol (30, 50 70 and 90%). Extracts (0.1 mg/ml) were tested for their anti-oxidative effects against xanthine oxidase as in Figure 1. Vitamin C (35.2 μg/ml) served as positive control. Data were expressed as% of inhibition where all the values were normalized by the control (no drug treatment), Mean ± SD, n = 6. Statistical significance is indicated as * P = 0.0419 for control (without extract) vs 70% EtOH and *** P = 0.0000852 for control (without extract) vs water, P = 0.000725 for control (without extract) vs 30% EtOH and P = 0.000897 for control (without extract) vs 90% EtOH.