含朱砂中药柏子养心丸毒性与安全性的体内外汞物质形态关联研究

Cinnabar is a typical traditional Chinese materia medica and it has been formulated in more than 10 percent of all the traditional Chinese medicines. However, the mechanisms of the clinical adverse reactions and the toxicities of these cinnabar containing TCMs are not clear. The FDA and the Department of Health of the Government of the Hong Kong Special Administrative Region have issued import alerts about the Chinese medicines many times for they have been found to contain excessive mercury. Most of the patients also cast doubt on the safety and toxicity of these TCMs. Although the toxicology has demonstrated that most of the water soluble inorganic and organic mercury are highly toxic with severe damage to the central nerve system and extreme toxicity to infant and new born babies, the Chinese Pharmacopoeia has included more than twenty cinnabar containing TCMs for pediatric uses. Therefore, the investigation about the toxicity of the cinnabar containing TCMs is essential from the determination of the in vivo water soluble inorganic and organic mercury species point of view. The present project will study the Cinnabar containing Traditional Chinese Medicine - Baizi Yangxin Wan, which has a long history of clinical prescription in China and is now an OTC drug listed in the National Essential Drugs. The advanced HPLC cold vapor generation atomic fluorescence spectrometry and HPLC-ICP/MS techniques will be established for the analysis. The mercury speciation will be launched for both rats and beagle dogs after oral administration of single and multiple doses of cinnabar alone or Baizi Yangxin Wan equivalent to the human clinical dosages or at elevated 10 times doses for the toxicity study. The in vitra and in vivo mercury species will be identified and the corresponding ADME characteristics estimated. The water soluble inorganic and organic mercury species found in the test animals and the pharmaco- and toxico- kinetics will be compared with those found for the clinically therapeutic patient's after the administration of Baizi Yangxin Wan. And finally, the relevant toxicity mechanisms will be located which are of great importance for the safe and effective clinical application of this cinnabar containing medicine.

朱砂为传统中药材并10%以上中成药中配方使用，但是含朱砂中成药的不良反应与毒性机制尚不明确。美国FDA和香港卫生署等机构对含朱砂中成药多次发出安全警示，患者对其安全性和毒性也存在疑惑。毒理学证明各种可溶性汞盐和有机汞均有剧毒，主要影响神经系统，尤其严重伤害儿童，而中国药典仍然收载对神经系统具有镇惊熄风的儿童用含朱砂中成药数十种。因此，从体内可溶性汞盐和有机汞的形态分析入手，研究含朱砂中成药的毒副反应机制十分必要。本项目以临床常用的含朱砂国家基本药物柏子养心丸为对象；建立先进的汞形态分析HPLC-冷原子蒸气-原子荧光和HPLC-电感耦合等离子/质谱技术；从体外到体内的角度，对大鼠和比格犬分别给予治疗和毒性剂量的单味朱砂或柏子养心丸，研究它们体内的汞形态与吸收、分布、转化和消除行为；并与患者临床治疗时体内的汞形态进行比较；揭示柏子养心丸与汞形态相关的毒性机制，为其用药安全提供基于汞形态的依据。

朱砂(HgS)作为传统中药材，常配伍使用，临床应用历史悠久，但因其含有大量汞元素，不良反应时有报道，使得含朱砂中成药的安全性受到了严重质疑。但朱砂水中极难溶解，难以被人体吸收；不同形态的汞化合物的毒性差别极大。本研究利用高效液相色谱-冷原子蒸气-原子荧光(HPLC-CV-AFS)联用技术，从体外到体内，从汞元素与汞形态分析出发，考察含朱砂中成药与汞相关的安全性与毒性；对比单味朱砂药材与复方，研究复方配伍的机制，为含朱砂中成药临床的安全合理使用提供参考。研究成果如下：. 比较了朱砂与含朱砂中成药在体外模拟胃肠液中的溶出过程，探索合理的安全性评价指标。结果显示，胃肠道活动与复方配伍促进了朱砂中汞的溶出，但可溶性汞含量显著低于总汞含量；在含朱砂中成药的正常剂量范围内摄入的可溶性汞暴露量在安全限度范围(30μg/天)内，使用“可溶性汞的日暴露量”代替总汞含量评价安全性更科学合理。. 考察了单味朱砂与柏子养心丸全方给药后汞在大鼠体内的吸收、分布过程的差异，分析配伍对朱砂药动学的影响。结果显示，与朱砂相比，柏子养心丸复方配伍后汞的Cmax增加，Tmax 显著降低，t1/2、AUC显著增加，说明复方配伍对朱砂的药代动力学行为有影响。在多次给药达稳态后，蓄积因子显示汞在体内有一定的蓄积。柏子养心丸组大鼠消化道中汞的浓度显著高于朱砂组；在毒性剂量下，汞会大量进入心、肝、脾、肺、肾和脑组织中。长期给药后，汞容易在肝、肾与消化系统中蓄积，经组织切片观察，柏子养心丸组、朱砂组的大鼠肝、脑有轻微组织形态学的改变，提示朱砂或柏子养心丸均不可超量久服，以免造成神经中毒或肝脏损伤。. 考察了人体口服柏子养心丸后血液与尿液中总汞与汞形态的经时变化过程。结果显示，人体单次服用柏子养心丸后，血液与尿液中的汞浓度较低，均以Hg(II)形态存在；连续服用后血液与尿液中汞浓度高于单次，消除缓慢，以Hg(II)形态为主，但检测到极微量甲基汞，未检出乙基汞和苯基汞，说明在医生指导下，短期服用柏子养心丸是安全可靠的。