Neuroprotective effects of 3-O-demethylswertipunicoside against MPTP-induced Parkinson's disease in vivo and its antioxidant properties in vitro.

3-O-demethylswertipunicoside (3-ODS) has been reported to protect dopaminergic neurons against neurotoxicity induced by 1-methyl-4-phenylpyridinium (MPP(+)) in PC12 cells. Here, we investigate the neuroprotective effects in vivo and antioxidant activities in vitro of 3-ODS. In the 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine (MPTP)-treated mouse model of Parkinson's disease (PD), 3-ODS dose-dependently improved motor coordination (as shown by rotarod test), increased the contents of dopamine (DA) and its metabolites in the striatum, and increased the number of tyrosine hydroxylase (TH)-positive neurons in the substantia nigra (SN). In addition, 3-ODS also increased the spine density in hippocampal CA1 neurons. In antioxidant assays, 3-ODS showed a strong capacity in scavenging hydroxyl radical, superoxide anion and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical in a concentration-dependent manner. Taken together, we conclude that 3-ODS attenuates the PD-related motor deficits mainly through its neuroprotective effects, growth-promoting effects on spine density, and its antioxidant activities.