[Protective effect of curcumin on dopamine neurons in Parkinson's disease and its mechanism]

To investigate the effect of curcumin on dopamine neurons in Parkinson's disease (PD) and its mechanism.

SH-SY5Y human neuroblastoma cells were treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to establish the PD cell model. The model cells were treated with curcumin and/or autophagy inhibitor 3-MA. After 48 h of drug treatment, the number of surviving dopamine neurons was detected by tyrosine hydroxylase immunofluorescence method. Western blotting was used to detect protein expression of α-Synuclein (α-Syn), transcription factor EB (TFEB) and autophagy-related proteins lysosome-associated membrane protein 2A (LAMP2A) and microtubule-associated protein 1 light chain 3-Ⅱ(LC3-Ⅱ); RT-PCR was used to detect mRNA expression of α-Syn.

Compared with MPTP model group, curcumin increased the number of surviving dopamine neurons(P<0.01), decreased both protein expression and mRNA expression of α-Syn (all P<0.01), and increased protein expression of TFEB, LAMP2A and LC3-Ⅱ (all P<0.01). When curcumin and 3-MA were given concurrently, the number of surviving dopamine neurons, protein expression of TFEB, LAMP2A and LC3-Ⅱ increased (P<0.05 or P<0.01), and both protein expression and mRNA expression of α-Syn decreased (P<0.05 or P<0.01) compared with MPTP model group; but the number of surviving dopamine neurons and protein expression of LAMP2A and LC3-Ⅱ decreased compared with curcumin group (all P<0.05).

Curcumin exerts protective effect on dopamine neurons in PD, which may be associated with enhancing autophagy and promoting the clearance of α-Syn.