To clarifywhether the cell-protective capacity of Rb2 was associated
with its antioxidant property,we tested ROS production using a fluorescent
probe DCFH-DA. The results in Fig. 6 showed that whenMC3T3-E1
cellswere treatedwith 0.3mMH2O2, ROS increased. These data indicated
that H2O2 stimulated the generation of oxidants and resulted in
oxidative stress toMC3T3-E1 cells. However, when pretreated with Rb2
of different concentrations, ROS production was partially suppressed (Fig. 6). These results suggested that the protection by Rb2 might be
related to its antioxidant activity.