Effect of SR10 on prolongation of copper ion-induced LDL oxidation. LDL in PBS was incubated with 5 μM CuCl2 at 37°C in the presence or absence of SR10, and ascorbic acid (positive control). Conjugated diene formation was measured by determining the absorbance at 234 nm at every 5 minutes for totally 24 hours. A figure showing one representative experiment of three trials was shown in panel A. Lag time was determined as the intercept of the slopes for the lag phase and propagation phase. Difference of lag time between treatment and control (PBS only) was defined as lag phase prolongation. Results of lag phase prolongation time from three independent trials was shown in panel B. Values are expressed as mean ± S.D. for three independent experiments. By Mann-Whitney test, significant difference when compared to PBS control was indicated by # p < 0.01.