Effects of Salacia oblonga root extract on cardiac hypertrophy

描述（由申请人提供）：心脏肥大是充血性心力衰竭的主要风险因素，充血性心力衰竭是许多心脏疾病的终末期疾病。心脏中脂质和氧化还原稳态的失调参与了心脏肥大和心力衰竭的发展。五层龙根的水提取物，一种广泛使用的Ayuvedic药物和传统中药，用于糖尿病和肥胖症，已被证明可以改善Zucker糖尿病脂肪大鼠的餐后高血糖和心脏纤维化。五层龙根提取物（SORE）已被证明激活过氧化物酶体增殖物激活受体α（PPARalpha），核受体超家族的成员。我们的初步研究表明，在Zucker瘦大鼠的SORE治疗激活心肌肉毒碱棕榈酰转移酶I，线粒体脂肪酸氧化（FAO）的关键酶的表达。此外，SORE抑制血管紧张素II和苯肾上腺素诱导的心肌细胞肥大生长。我们将使用体外，体内和离体方法的组合来测试我们的中心假设，即SORE通过激活PPARalpha来改善病理性心脏肥大，以纠正伴随的心肌FAO减少，以及由于心肌细胞缺乏PPARdelta，另一种控制FAO的PPAR亚型。我们还将测试一个假设，即SORE作为抗氧化剂，以防止对心脏的氧化损伤。具体而言，我们将实现以下具体目标：1，确定SORE治疗对小鼠中响应于压力超负荷的心脏肥大的发展的影响; 2，确定SORE的抗肥大作用的潜在机制是否与其PPARalpha激活作用相关; 3，确定SORE是否作为抗氧化剂发挥其抗肥大作用。我们将描述SORE对压力超负荷条件下PPARalpha缺失小鼠和心肌细胞限制性PPARdelta敲除小鼠的基因表达、心脏形态、心脏功能和氧化应激的影响。这些研究的结果应提供新的药理学机制的潜在调节作用的SORE对心脏代谢紊乱，与心脏肥大的肥大刺激或遗传缺陷的关键脂肪酸代谢转录调节相关。本研究的结果将为预防和治疗心肌肥厚和心力衰竭提供新的治疗选择。心脏肥大是充血性心力衰竭的主要危险因素，充血性心力衰竭是许多心脏疾病的终末期状况。该研究将为SORE对与心脏肥大相关的心脏代谢紊乱的潜在调节作用提供新的药理学机制。本研究的结果将为预防和治疗心肌肥厚和心力衰竭提供新的治疗选择。

DESCRIPTION (provided by applicant): Cardiac hypertrophy is the main risk factor for congestive heart failure, which is the end-stage condition of a number of cardiac disorders. Deregulations of lipid and redox homeostasis in the heart are involved in the development of cardiac hypertrophy and heart failure. Water extract of Salacia oblonga root, a broadly used Ayuvedic medicine and traditional Chinese medicine for diabetes and obesity has been shown to improve postprandial hyperglycemia and cardiac fibrosis in Zucker Diabetic Fat rats. Salacia oblonga root extract (SORE) has been shown to activate Peroxisome proliferater activated receptor alpha (PPARalpha), a member of the nuclear receptor superfamily. Our preliminary studies revealed that SORE treatment in Zucker lean rats activated cardiac expression of carnitine palmitoyl transferase I, a key enzyme in mitochondria fatty acid oxidation (FAO). Furthermore, SORE suppressed Angiotensin II and phenylepherine induced hypertrophic growth in cultured cardiomyocytes. We will use a combination of in vitro, in vivo and ex vivo methods to test our central hypothesis that SORE improves pathological cardiac hypertrophy by activating PPARalpha to correct the companied diminished myocardial FAO and due to cardiomyocyte deficiency of PPARdelta, another PPAR subtype that govern FAO. We will also test a hypothesis that SORE acts as antioxidants to prevent oxidative damage to the heart. Specifically, we will achieve the following specific aims:1, define the effects of SORE treatment on the development of cardiac hypertrophy in response to pressure-overload in mice; 2, identify whether the mechanism underlying SORE's antihypertrophic effect is correlated with its PPARalpha activation action; 3, determine if SORE acts as anti-oxidant to exert its anti-hypertrophic effects. We will characterize effects of SORE on gene expression, cardiac morphology, cardiac function and oxidative stress in mice with PPARalpha null under pressure-overload condition and in mice with cardiomyocyte-restricted PPARdelta knockout. Results from these studies should provide novel pharmacological mechanisms on the potential regulating effects of SORE on cardiac metabolic disorders that are associated with cardiac hypertrophy in response to hypertrophic stimuli or genetic defect of a key fatty acid metabolic transcriptional regulator. Results from this study should provide novel therapeutic option in preventing and treating cardiac hypertrophy and heart failure. Cardiac hypertrophy is the main risk factor for congestive heart failure, which is the end-stage condition of a number of cardiac disorders. The proposed study will provide novel pharmacological mechanisms on the potential regulating effects of SORE on cardiac metabolic disorders that are associated with cardiac hypertrophy. Results from this study should provide novel therapeutic option in preventing and treating cardiac hypertrophy and heart failure.