CYCS and Parkinson disease: In addition, the neuroprotective effects of luteolin on MPP+-induced apoptosis were confirmed by western blot analysis using the neuropathological hallmark protein of PD, such as dopaminergic neuronal protein marker and apoptotic protein, including α-synuclein, TH, Bax, Bcl-2, cytochrome c, caspase-3 and cleaved caspase-3.