Curcumin attenuated the mitochondrial apoptosis-signaling pathway in SNc. (A) Effects of curcumin on the level of Bax induced by MPTP in cytosol and mitochondria in SNc. (B) Effects of curcumin on the level of cyt c induced by MPTP in cytosol and mitochondria in SNc. COX4 was strongly expressed in the mitochondrial fraction and did not decrease after MPTP lesion, while no immunoreactivity was seen in the cytosolic fraction of SNc region in both the saline and MPTP groups. Bands corresponding to Bax and cyt c were scanned and the intensities were represented as folds vs. saline groups. Data are expressed as the mean ± SD and as folds vs. respective saline. aP < 0.05 vs. saline; bP <0.05 vs. MPTP groups (n = 6 mice).