Protective effects of simvastatin on injured dopaminergic neurons in Parkinson's disease rats induced by lipopolysaccharide / 中华行为医学与脑科学杂志

ABSTRACT

Objective To examine the effect of simvastatin treatment on Parkinson's disease rats induced by lipopolysaccharide (LPS) and its mechanism.Methods The LPS-PD model was established by injection of LPS (5 mg/mL) into the right substantia nigra compacta (SNC),and rats were randomly divided into control group,LPS-model group and simvastatin treatment group with 15 rats in each group.Rats in the simvastatin treatment group was intraperitoneally administered simvastatin (5 mg/kg) before,and daily for 14 days after surgery,while the control group and LPS-model group received same volume normal saline and LPS respectively.Ionized calcium binding adaptor molecule 1 (Iba-1)-positive cells and the expression of tyrosine hydroxylase (TH),tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the SNC were detected by immunohistochemistry,Western blotting and enzyme-linked immunosorbent assay,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,and comparison of the intact side to reduce 81.13％ (P＜0.01) in the SNC,as well as increases in the Iba-1-positive cell number,iNOS,IL-1β and TNF-α expression (P＜0.05).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 inhibiting glial cells (astrocytes and microglia) activation,and playing an anti-inflammatory role,thus improving substantia nigra function.