益智仁挥发油对帕金森病模型小鼠脑内纹状体和黑质损伤的影响

Effect of volatile oil extracted from Alpinia oxyphylla Miq.fruit on injured corpus striatum and substantia nigra of Parkinson disease model mice

目的观察益智仁挥发油(VOA)脑保护作用的机制。方法C57BL小鼠随机分为正常对照组、帕金森病(PD)模型组、司来吉兰10mg·kg-1阳性对照组,VOA0.278,0.833和2.5mL·kg-1组。除正常对照和模型组外,各给药组分别预先ig给予VOA或司来吉兰,每天1次,连续12d。第6天开始,除正常对照组外,各组ip给予1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)30mg·kg-1,每天1次,连续7d,制备PD小鼠模型。末次给药后第2天处死小鼠,荧光分光光度法测定小鼠脑内纹状体高香草酸(HVA)和5-羟色胺(5-HT)含量,比色法检测纹状体内超氧化物岐化酶(SOD)活性、还原型谷胱甘肽(GSH)和丙二醛(MDA)含量,SABC免疫组化法测定黑质致密部神经细胞内Bcl-2和天冬氨酸半胱氨酸蛋白酶3(caspase 3)的表达。结果与正常对照组比较,模型组小鼠脑内纹状体HVA,5-HT和GSH含量显著下降,SOD活性下降,MDA含量明显升高;黑质致密部Bcl-2和caspase 3免疫阳性细胞数增加。预先给予VOA0.833和2.5mL·kg-1可明显抑制MPTP所诱导的HVA和GSH含量及SOD活性的降低,并抑制MDA含量升高,2.5mL·kg-1可明显抑制5-HT含量降低。VOA0.833和2.5mL·kg-1可增加黑质致密部Bcl-2免疫阳性细胞数,减少caspase 3免疫阳性细胞数。VOA2.5mL·kg-1的作用与司来吉兰的作用相近。结论VOA的脑保护作用可能与其增加脑内纹状体单胺类神经递质释放、减轻氧化应激反应以及减少黑质致密部神经元凋亡等因素有关。

AIM To investigate the mechanism of volalile oil extracted from Alpinia oxyphylla Miq. fruit （ VOA ） brain protection. METHODS underlying the C57BL mice were randomly divided into 6 groups： normal control, model, positive control selegiline 10 mg·kg-1 group, VOA 0. 278,0. 833 and 2.5 mL· kg-1 groups. Except normal control and model groups, the mice were preadministrated ig VOA or selegiline, once daily for 12 d. On the 6th day, except normal control group, the mice were ip given 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine （MPTP） 30 mg-kg 1 once daily for 7 d to prepare Parkinson disease mod- el. All the mice were sacrificed on the next day after the last administration. The contents of homovanillic acid （HVA） and 5-hydroxy- tryptamine （5-HT） in mice corpus striatum were determined by using fluorophotometer. The superoxide dismutase （SOD） activity, glu- tathione （ GSH ） and maleic dialdehyde （MDA） contents in mice corpus striatum were determined with colorimetric assay. The expres- sion of Bcl-2 and caspase 3 in nerve cells of substantia nigra was detected by using SABC immunohisto-chemical method. RESULTS Compared with normal control group, HVA, 5- HT and GSH contents, and SOD activity in cor- pus striatum of model mice decreased, and MDA content increased significantly. Otherwise, numbers of Bcl-2 and caspase 3 immune reaction positive cells in substantia nigra in- creased significantly. Pre-administration of VOA 0. 833 and 2.5 mL· kg-1 significantly in- hibited HVA and GSH contents and SOD activity decrease induced by MPTP, and MDA con- tent was inhibited, too. VOA 2.5 mL·kg-1 in- hibited decrease of 5-HT content. VOA 0. 833 and 2.5 mL· kg -1 increased Bcl-2 and inhibited caspase 3 expressions in substantia nigra of model mice. The effects of VOA 2.5 mL. kg- on the above parameters were similar with those of selegiline. CONCLUSION The protection of VOA on brain may relate to the release of monoami neurotransmitters in corpus striatum increased, oxidative stress alleviated and neu- ronal apoptosis in substantia nigra reduced.