Effects of puerarin on (A) respiratory bursts in human neutrophils, and (B) the antioxidation in thiobarbituric acid-reactive substance (TBARS) in rat brain homogenate. (A) Washed neutrophil suspensions (2 × 106 cells/ml) were preincubated with the solvent control (0.5% DMSO) or various concentrations of puerarin (10, 20, and 50 μM) in the presence of lucigenin (100 μM), followed by the addition of fMLP (800 nM) to trigger neutrophil respiratory bursts. Data are presented as a percent inhibition of the solvent control (means ± S.E.M., n = 4). (B) Brain homogenates were preincubated with solvent (0.5% DMSO) or various concentrations of puerarin (20~500 μM) for 10 min followed by the addition of Fe2+ (200 μM). Results are presented as the absorbance at 532 nm/mg protein in brain homogenates. Data are presented as the means ± S.E.M. (n = 4). **P < 0.01 compared with the solvent group (DMSO only).