OBJECTIVETo investigate the protective effects of cistanche total glycosides (CTG) on dopaminergic neuron in substantia nigra (SN) of model mice of Parkinson's disease (PD).

METHODSExperimental mice were randomly divided into 5 groups, the normal control group, the model group, the high (400 mg/kg), moderate (200 mg/kg) and low (100 mg/kg) dose CTG groups. Mouse model of chronic PD was induced by peritoneal injection of MPTP (1-methyl-4-phenyl-1,2,3,6-ttrahydropyridine) 30 mg/kg for 5 successive days. Climbing test was used to estimate the neurobehavior of mice on the 7th and 14th day (D7 and D14) after initiating MPTP injection; meantime, quantitative immunohistochemistry was conducted to detect the number of dopaminergic neuron in SN and expression of tyrosine hydroxylase (TH) in striatum.

RESULTSThe average time of climbing in the high dose CTG group on D7 and D14 was significantly shorter than that in the model group (P < 0.01). The mean optic density (OD) of TH in striatum was higher in the three CTG groups than that in the model group on D7 (P < 0.01); but on D14, significance only showed in the high and moderate dose CTG groups (P < 0.01). Moreover, the MPTP induced decrease of TH positive neuron could be antagonized by CTG, but significant difference only showed between the high dose CTG group and the model group at the two time points of observation (P < 0.05).

CONCLUSIONCTG could improve the neurobehavior of PD model mice significantly, and inhibit the decrease of nigral dopaminergic neurons and TH expression in striatum.