Abstract
Purpose: Parkinson’s
disease (PD) is a common neurodegenerative disorder characterized by disabling
motor abnormalities, which include tremor, muscle stiffness, paucity of
voluntary movements, and postural instability. Silymarin (SM) or milk thistle
extract, is known to own antioxidative, anti-apoptotic, anti-inflammatory and
neuroprotective effects. In the present study, we investigated the effect of
intraperitoneal (i.p) administration of SM, on 6-OHDA-induced motor-impairments
(catalepsy and imbalance) in the rats.
Methods: Experimental model of PD was
induced by unilateral infusion of 6-hydroxydopamine (6-OHDA; 8 μg/2 μl/rat)
into the central region of the substantia nigra pars compacta (SNc). Catalepsy
and motor coordination were assessed by using of bar test and rotarod
respectively.
Results: The results showed a significant (p<0.001) increase
in catalepsy of 6-OHDA-lesioned rats whereas; in SM (100, 200 and 300 mg/kg,
i.p for 5 days) treated hemi-parkinsonian rats catalepsy was decreased markedly
(p<0.001). Furthermore, there was a significant (p<0.001) increase in
motor-imbalance of 6-OHDA-lesioned rats. SM improved motor coordination
significantly (p<0.001) in a dose dependent manner and increased motor
balance.
Conclusion: In conclusion, we found that short-term treatment with
SM could improve 6-OHDA-induced catalepsy and motor imbalance in rats. We
suggest that SM can be used as adjunctive therapy along with commonly used
anti-parkinsonian drugs. However, further clinical trial studies should be
carried out to prove this hypothesis.