ABSTRACT
OBJECTIVE: To investigate the effects of simvastatin on the expression of inducible nitric oxide synthase (iNOS) and brain-derived neurotrophic factor (BDNF) in the substantia nigra in a lipopolysaccharide (LPS)-induced rat model of Parkinson disease (PD), and to study the mechanisms underlying the neuroprotective effects of simvastatin in PD. METHODS: The LPS-PD model was established by injection of LPS (5 mg/mL, 2.0 µL) into the right substantia nigra compacta (SNC). Rats in the sham-operated group received saline. The simvastatin treatment group was intraperitoneally administered simvastatin (5 mg/kg, 2.0 µL) at 1 h before, and daily for 14 days after surgery, while the sham-operated and LPS-model groups received saline. Iba-1-positive cells and tyrosine hydroxylase (TH), as well as iNOS and BDNF in the SNC were detected by immunohistochemistry and Western blotting, respectively. The effect of simvastatin in the PD model was also examined in behavioral tests. RESULTS: The LPS-model group exhibited typical animal PD behaviors. Compared with the control group, the LPS-model group exhibited a decreased number of DA neurons (p < 0.01) in the SNC, as well as increases in the Iba-1-positive cell number and iNOS expression (p < 0.05), while BDNF expression was downregulated (p < 0.01). These effects were inhibited by simvastatin treatment (p < 0.05). CONCLUSION: Simvastatin mediates a protective effect on dopaminergic neurons in the SNC in the LPS-PD model, possibly by promoting neuronal repair and regeneration, and by inhibiting oxidative stress, thus improving substantia nigra function.
Subject(s)
Brain-Derived Neurotrophic Factor/metabolism , Neuroprotective Agents/pharmacology , Nitric Oxide Synthase Type II/metabolism , Parkinson Disease, Secondary/metabolism , Pars Compacta/drug effects , Simvastatin/pharmacology , Animals , Dopaminergic Neurons/drug effects , Dopaminergic Neurons/metabolism , Lipopolysaccharides , Male , Parkinson Disease, Secondary/chemically induced , Pars Compacta/metabolism , Rats , Rats, Sprague-Dawley , Tyrosine 3-Monooxygenase/metabolismABSTRACT
Objective: To investigate the neuroprotective effects of simvastatin on lipopolysaccharide (LPS)-induced rat model of Parkinson's disease (PD) and the mechanisms involved. Methods: Hemiparkinsonian rat models were induced by stereotaxieal injection of LPS in the right substantia nigra compacta. After 2 weeks of simvastatin treatment, rotational behavior test was performed after the intraperitoneal injection of apomorphine. Expression of tyroxine hydroxylase (TH) and glial fibrillary acidic protein were analyzed through immunohistochemical staining of substantia nigra and striatum, and the level of TNF- α was evaluated using enzyme-linked immunosorbent assay. Results: Comparing with untreated group, behavioral symptoms of the rats were significantly less in the rats that received simvastatin treatment. The TH positive cell count in substantia nigra and striatum were significantly increased (. P<0.05) and TNF- α expression was significantly decreased (. P<0.05) in simvastatin group compared to untreated group. Conclusions: Simvastatin could effectively inhibit the activation of astrocytes, reduce TNF- α expression, and exert anti-inflammatory effects, and thus protect the dopaminergic neurons in substantia nigra and striatum of the rat model of PD.
ABSTRACT
OBJECTIVE@#To investigate the neuroprotective effects of simvastatin on lipopolysaccharide (LPS)-induced rat model of Parkinson's disease (PD) and the mechanisms involved.@*METHODS@#Hemiparkinsonian rat models were induced by stereotaxieal injection of LPS in the right substantia nigra compacta. After 2 weeks of simvastatin treatment, rotational behavior test was performed after the intraperitoneal injection of apomorphine. Expression of tyroxine hydroxylase (TH) and glial fibrillary acidic protein were analyzed through immunohistochemical staining of substantia nigra and striatum, and the level of TNF- α was evaluated using enzyme-linked immunosorbent assay.@*RESULTS@#Comparing with untreated group, behavioral symptoms of the rats were significantly less in the rats that received simvastatin treatment. The TH positive cell count in substantia nigra and striatum were significantly increased (P<0.05) and TNF- α expression was significantly decreased (P<0.05) in simvastatin group compared to untreated group.@*CONCLUSIONS@#Simvastatin could effectively inhibit the activation of astrocytes, reduce TNF- α expression, and exert anti-inflammatory effects, and thus protect the dopaminergic neurons in substantia nigra and striatum of the rat model of PD.
