银杏叶提取物对1—甲基—4—苯基—1，2，3，6—四氢吡啶所致帕金森症的保护作用及机制

目的:观察银杏叶提取物(EGb)对1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)及其离子1-甲基-4-苯基吡啶(MPP~ )诱导的帕金森症(PD)模型的保护作用。方法:用脑立体定位仪向黑质(AP-5.4mm,-2.2mm,H8.3mm)内注射MPTP诱导大鼠旋转。在注射MPTP 24h后将大鼠处死,硫代巴比妥法测定黑质中丙二醛(MDA),羟胺法(即改进的黄嘌呤氧化酶法)测定黑质中超氧化物歧化酶(SOD),荧光分光光度法(激发波长310nm,发射波长390nm)测定纹状体中多巴胺(DA)的含量。MPP~ 诱导PC12细胞凋亡,HE染色,光镜下观察凋亡细胞;吖啶橙/溴乙锭(AO/EB)染色,荧光显微镜记数凋亡细胞,观察不同浓度EGb(25,50,100mg/L)在6h,12h,24h对细胞凋亡率的影响。结果:EGb 100mg/kg组可减少模型鼠的旋转次数及旋转持续时间(n=10,P<0.05);与MPTP组比较,EGb 50mg/kg和100mg/kg组MDA相对降低,SOD及DA相对增高(n=10,P<0.05和P<0.01)。MPP~ 10μmol/L可诱导PC12细胞凋亡,EGb 50和100mg/L组在6h,12h,24h可降低细胞凋亡率(P<0.05和P<0.01,n=3)。结论:EGb对MPTP诱导的PD动物模型及其离子MPP~ 诱导的PD细胞模型均有保护作用,其保护机制与清除自由基及抑制神经元凋亡有关。

Protective effect and mechanism of Ginkgo biloba leaf extracts for Parkinson disease induced by 1-methyl-4-phenyl-1,2,3,6-tetra-hydropyridine

AIM: To observe the effects of extracts of Ginkgo biloba leaves (EGb) on the Parkinson disease (PD) models induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and its ion 1-methyl-4-phenylpyridinium (MPP+). METHODS: MPTP was microinjected into substantia nigra of rats to induce a behavior change of rotation. EGb (ip, 50 or 100 mg.kg(1 . d-1) was pretreated consecutively for 19 d before MPTP administered and 1 d after MPTP administered. The contents of malondialdehyde (MDA), superoxide dismutase (SOD), and dopamine (DA) in substantia nigra of model rats were determined. Apoptosis of PC12 cells was induced by MPP+, and the protective effect of EGb (25, 50, and 100 mg/L) was also observed. The cells of apoptosis were observed under a microscope and counted under a fluoroscope after stained with AO/EB. RESULTS: EGb (100 mg . kg-1 . d-1) decreased the duration and frequency of the rotation of rats (P < 0.05, n = 10 ) while EGb (50 or 100 mg/L)inhibited the decreases of DA and SOD and the increase of MDA induced by MPTP, (P < 0.05 or P < 0.01, n = 10). MPP+ (10 micromol/L) induced the apoptosis of PC12 cells, and EGb (50 or 100 mg/L) prevented cells from apoptosis at 6 h, 12 h, and 24 h (P < 0.05 or P < 0.01, n = 3). CONCLUSION: EGb possesses protective effect on the PD models in vivo and in vitro. The anti-oxidation and anti-apoptosis may be one of the mechanisms underlying the neuroprotective effect of EGb.