虎杖白藜芦醇及其脂质体剂型对帕金森病模型大鼠黑质细胞保护作用的研究

Resveratrol derived from Rhizoma Et Radix Polygoni Cuspidati and its liposomal form protect nigral cells Of Parkinsonian rats

目的:氧化应激是帕金森病发病机制中的重要病理因素,是导致黑质多巴胺能神经元死亡的主要原因之一。白藜芦醇具有广泛的药理学作用和较强的抗氧化特性。本研究探讨从中药虎杖提取的白藜芦醇及其脂质体制剂对帕金森病模型大鼠黑质细胞的保护效应,为临床帕金森病治疗药物的开发提供实验依据。方法:实验用W istar大鼠50只,随机分为正常组、假手术组、模型组、白藜芦醇干预组、白藜芦醇脂质体干预组,以6-羟基多巴胺单侧纹状体微量注射法制备帕金森病大鼠模型。白藜芦醇干预组及白藜芦醇脂质体干预组在造模成功后,以白藜芦醇、白藜芦醇脂质体灌胃,20 mg.kg-1,1次/d,连续14 d。观察各组大鼠的旋转行为学改变,采用HE染色、N issl染色、酪氨酸羟化酶(TH)免疫组化方法统计黑质细胞总数、神经元总数、多巴胺能神经元数量,采用TUNEL法检测黑质细胞凋亡,以分光光度法检测黑质区总ROS活力和总抗氧化能力。结果:帕金森病模型大鼠在阿普吗啡诱导后,出现明显的行为学异常表现,黑质区细胞总数、神经元总数及多巴胺能神经元数量明显减少,凋亡细胞数量增加,组织总ROS活力显著增强,总抗氧化能力明显降低。白藜芦醇及白藜芦醇脂质体均能明显改善模型大鼠行为学异常,增加黑质区细胞总数、神经元总数、多巴胺能神经元数量,降低细胞凋亡率,提高组织总抗氧化能力,降低组织总ROS活力。在组织学指标的改善方面,白藜芦醇脂质体的效应较白藜芦醇单体更强。结论:中药虎杖来源的白藜芦醇及白藜芦醇脂质体对帕金森病模型大鼠黑质细胞具有明显的保护作用,这种保护作用可能与抗氧化活性有关。白藜芦醇脂质体较白藜芦醇单体在组织学指标改善上作用更强,可能与脂质体制剂提高了白藜芦醇的生物利用度有关。白藜芦醇脂质体可能是更有效的口服给药方式。

Objective： Oxidative stress is a hallmark in the pathogenesis of Parkinson＇disease （ PD）, which involves the selective loss of nigral dopaminergic neurons in PD. Resveratrol （3,5,4＇-trihydroxy-trans-stilbene） is well known for its powerful antioxidant property and a wide range of other biological effects. In this study, we investigated the protective effect of resveratrol derived from Rhizoma Et Radix Polygoni Cuspidati and its liposomal form on the nigral cells of PD rats induced by unilateral microinjection of 6-hydroxy dopamine in the striatum. The results showed that after 14 days gavage of resveratrol and resveratrol liposome respectively （20 mg · kg^-1 WB per day）, the abnormal rotational behavior of PD rats were deceased evidently, the numbers of total nigral cells, total nigral neurons and TH immuno-positive neurons were more than that of PD rats without given resveratrol or resveratrol liposome, simultaneously, the number of apoptotic nigral cells were decreased obviously. The results also showed that resveratrol and resveratrol liposome could decrease the total ROS activity, increase the total antioxidant capability of the nigral tissues. All the data indicated that resveratrol liposome performed stronger effects than resveratrol except for behavioral improvement. Our study confirmed that resveratrol derived from Rhizoma Et Radix Polygoni Cuspidati and its lipesomal form could inhibit the loss of dopaminergic neurons of PD rats, the under- lying mechanism may be attributed to their radical scavenging effect and antioxidant property. Due to presumably increased bioavailability, resveratrol liposome possesses the stronger therapeutic effect and may become a better clinical agent for the treatment of PD than free resveratrol.