Lim Yi-Cheng, Budin Siti Balkis, Othman Faizah, Latip Jalifah, Zainalabidin Satirah
Programme of Biomedical Science, School of Diagnostic and Applied Health, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300, Kuala Lumpur, Malaysia.
Department of Anatomy, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Center, Jalan Yaacob Latif, Bandar Tun Razak, 56000, Cheras, Kuala Lumpur, Malaysia.
Cardiovasc Toxicol. 2017 Jul;17(3):251-259. doi: 10.1007/s12012-016-9379-6.
Roselle (Hibiscus sabdariffa Linn.) calyces have demonstrated propitious cardioprotective effects in animal and clinical studies; however, little is known about its action on cardiac mechanical function. This study was undertaken to investigate direct action of roselle polyphenols (RP) on cardiac function in Langendorff-perfused rat hearts. We utilized RP extract which consists of 12 flavonoids and seven phenolic acids (as shown by HPLC profiling) and has a safe concentration range between 125 and 500 μg/ml in this study. Direct perfusion of RP in concentration-dependent manner lowered systolic function of the heart as shown by lowered LVDP and dP/dt , suggesting a negative inotropic effect. RP also reduced heart rate (negative chronotropic action) while simultaneously increasing maximal velocity of relaxation (positive lusitropic action). Conversely, RP perfusion increased coronary pressure, an indicator for improvement in coronary blood flow. Inotropic responses elicited by pharmacological agonists for L-type Ca channel [(±)-Bay K 8644], ryanodine receptor (4-chloro-m-cresol), β-adrenergic receptor (isoproterenol) and SERCA blocker (thapsigargin) were all abolished by RP. In conclusion, RP elicits negative inotropic, negative chronotropic and positive lusitropic responses by possibly modulating calcium entry, release and reuptake in the heart. Our findings have shown the potential use of RP as a therapeutic agent to treat conditions like arrhythmia.
玫瑰茄（Hibiscus sabdariffa Linn.）花萼在动物和临床研究中已显示出有益的心脏保护作用；然而，其对心脏机械功能的作用却知之甚少。本研究旨在探讨玫瑰茄多酚（RP）对Langendorff灌注大鼠心脏功能的直接作用。在本研究中，我们使用了RP提取物，其由12种黄酮类化合物和7种酚酸组成（通过HPLC分析显示），安全浓度范围为125至500μg/ml。浓度依赖性地直接灌注RP可降低心脏的收缩功能，表现为左心室舒张末期压力（LVDP）和dp/dt降低，提示负性变力作用。RP还降低了心率（负性变时作用），同时增加了最大舒张速度（正性变松弛作用）。相反，RP灌注增加了冠状动脉压力，这是冠状动脉血流改善的一个指标。RP消除了L型钙通道[（±）-Bay K 8644]、兰尼碱受体（4-氯间甲酚）、β-肾上腺素能受体（异丙肾上腺素）和肌浆网钙ATP酶阻滞剂（毒胡萝卜素）的药理激动剂引起的变力反应。总之，RP可能通过调节心脏中的钙内流、释放和再摄取而引发负性变力、负性变时和正性变松弛反应。我们的研究结果表明RP有作为治疗心律失常等病症的治疗剂的潜在用途。
