Figure 3. Modulation of the SOD activity in undifferentiated PC12 cells after preincubation with HX, HY and HZ.

Cells were incubated with 200 µM H₂O₂ for 2 h. Huprines were added to the culture 48 h prior to H₂O₂ addition. SOD activity was measured with a SOD activity assay from Fluka. At least three independent experiments were carried out in triplicate. The data are means ± s.e.m. expressed as percentage of control value. *P<0.05 compared with H₂O₂ group (Dunnett's test).