Herbal Effects on Oxidant Dynamics in Cardiomyocytes

描述（由申请人提供）：急性和慢性心脏病，引起显著的发病率和死亡率，在传统医学系统中经常用草药治疗。由于活性氧（reactive oxygen species， ROS）介导了心脏病的发病机制，因此研究抗氧化类中药在预防或抑制心脏病中的作用及其机制具有十分重要的意义。研究了葡萄籽原花青素提取物（GSPE）和黄芩提取物（SbE）这两种具有抗氧化特性的常用草药，它们都是有效的活性氧清除剂。在目前的提案中，我们计划评估长期预处理提取物是否可以诱导抗氧化保护。我们的初步结果表明，用GSPE或SbE或提取物部分或某些活性成分预处理鸡心肌细胞48-72小时，对内源性和外源性氧化剂的攻击都有显著的保护作用。研究结果表明，草药预处理的间接作用降低了细胞内ROS活性，这将有利于心脏疾病。这可能是通过细胞内清除活性氧的草药代谢物和通过合成调节活性氧活性的蛋白质改变基因表达来实现的。我们假设用GSPE或SbE预处理心肌细胞可以显著减弱ros诱导的损伤，并通过上调细胞抗氧化能力介导ros依赖过程的改变。实验将在用实验草药预处理1-5天的新生小鼠心肌细胞模型中进行评估。具体目的是研究GSPE或SbE预处理是否能减轻模拟氧化应激下心肌细胞的氧化损伤，草药预处理是否能调节细胞对通过ROS介导的刺激的反应，以及这种改变的反应是否可以部分解释为抗氧化蛋白基因表达上调。我们还将评估抗氧化活性的上调是否可归因于提取物的特定生物活性部分和成分。随后将使用“敲除提取物”确认结果，其中活性成分从其原始基质中去除。拟议的研究将强调GSPE和SbE在改变心肌细胞ros依赖性活性结果中的作用。我们的研究结果可以证明这些草药在预防和治疗心脏病方面具有潜力。拟议的研究将强调GSPE和SbE在改变ros依赖性细胞事件结果中的作用。我们的研究结果可以证明草药在预防和治疗心脏病方面的巨大潜力。

DESCRIPTION (provided by applicant): Acute and chronic heart diseases, which cause significant morbidity and mortality, have often been treated by herbal medications in traditional medicinal systems. Since reactive oxygen species (ROS) mediate pathogenesis of heart disease, studying the role of antioxidant herbs in prevention or attenuation of heart disease and the involved mechanisms is extremely important. We propose to investigate two commonly used herbs with antioxidant properties, namely grape seed proanthocyanidin extract (GSPE) and Scutellaria baicalensis extract (SbE), which are potent ROS scavengers. In the current proposal, we plan to evaluate whether long-term pretreatment with the extracts can induce antioxidant protection. Our preliminary results in chick cardiomyocytes pretreated with either GSPE or SbE or extract fractions or some active constituents for 48-72 hr demonstrate significant protection against both an endogenous and exogenous oxidant onslaught. The findings suggest that indirect effects of herbal pretreatment reduce intracellular ROS activity, which would be of benefit in cardiac disease. This is possibly achieved by herbal metabolites within the cell that scavenge ROS and by altered gene expression with synthesis of proteins that modulate ROS activity. We hypothesize that pretreatment of cardiomyocytes with GSPE or SbE results in significant attenuation of ROS-induced injury and alteration in ROS-dependent processes mediated through upregulation of cellular antioxidant capacity. The proposed experiments will be evaluated in a neonatal mouse cardiomyocyte model pretreated with the test herbs for 1-5 days. The specific aims are to investigate whether pretreatment with GSPE or SbE attenuate oxidant injury in the cardiomyocytes during simulated oxidant stress, whether herbal pretreatment modulates cellular responses to stimuli that mediate actions through ROS, and whether the altered responses can be partly explained by upregulated gene expression of antioxidant proteins. We will also evaluate whether the upregulation of antioxidant activity can be attributed to specific bioactive fractions and constituents of the extracts. Results will subsequently be confirmed with the use of "knockout extracts" in which the active constituents are removed from their original matrix. The proposed study will highlight the role of GSPE and SbE in altering the outcome of ROS-dependent activity within cardiomyocytes. Our results could demonstrate that these herbs have a potential in the prevention and treatment of cardiac disease. The proposed study will highlight the role of GSPE and SbE in altering the outcome of ROS-dependent cellular events. Our results could demonstrate a significant potential of the herbs in the prevention and treatment of cardiac disease.