Table 1.

MTT assay of cell viability and optical density of TH positive PC12 cells.

Group	Cell viability	Optical density of TH positive PC12 cells
Control	0.49 ± 0.11	0.22 ± 0.07
MPP+	0.30 ± 0.07**	0.10 ± 0.03**
I (isoflavone)	0.61 ± 0.17*	0.46 ± 0.06*
I + MPP+	0.56 ± 0.16	0.24 ± 0.04
Z-YVAD-CHO + MPP+	0.59 ± 0.17***	0.22 ± 0.05***
Z-DEVD-CHO + MPP+	0.60 ± 0.11***	0.23 ± 0.02***

^* P < 0.05 compared with isoflavone + MPP⁺; ^** P < 0.05 compared with control; ^*** P < 0.05 compared with MPP⁺.