Fig. 3.

Inhibitory effects of curcumin, boiled curcumin mixture Cur-B1, and boiled curcumin mixture Cur-B2 on H₂O₂-induced PC12 cell apoptosis. PC12 cells were treated with 10 μg/mL curcumin, 360 μg/mL Cur-B1, and 360 μg/mL Cur-B2 for 0.5 h prior to exposure to 500 μM H₂O₂. Then, PC12 cells were observed by a phase contrast microscope (×200) (a). PC12 cells were stained with a double dye of annexin V-FITC/PI after treatment with curcumin or boiled curcumin mixture and the apoptosis rates of each group were detected by flow cytometer (b).