基于PK-PD模型木香肠粘膜保护作用与气体信号分子体系相关性研究

Radix Aucklandiae is one of the most commonly used traditional Chinese medicines in the gastrointestinal regulation. It exhibited a significant and concentration-dependent inhibition activity on the gastrointestinal contractions induced by potassium chloride and acetylcholine, whereas, the spasmolytic response of Radix Aucklandiae was reverted in the presence of the gaseous signal molecule synthases inhibitors. According to the results, we presume that antispasmodic ingredients in Radix Aucklandiae may be involved in the regulation of gastrointestinal motility through the pathway of endogenous gaseous signal molecules. And Radix Aucklandiae showed a strong protection of intestinal mucosa injury. There has no report involved in the interaction between the protections of intestinal mucosa injury of Radix Aucklandiae and gaseous signal molecules. Results of recent researches in digestive system proved that stable levels of gaseous molecules and the expression of relevant synthases play crucial roles for the regulation of gastrointestinal physiological functions. We believe that it necessary to examine the biological and potential therapeutic effects of these gases as a type theory of “gaseous triumvirate”. These three gases form what has come to be known as the whole system of gasotransmitters and one gas is not perhaps in some way more important than another. This theory is conformity with the concept on Holistic Medicine. At present the theory and method of the gasotransmitters system has not been studied in the traditional Chinese medicine of gastrointestinal system. The mode of PK-PD will be used to explore the new relationship between the whole regulation system of NO/CO/H2S and the mechanism of intestinal mucosa injury of the active ingredients in Radix Aucklandiae. It will provide a new theory and method for traditional Chinese medicine on the protection of intestinal mucosa injury.

木香是胃肠功能调节中使用频次最高的中药之一，本课题组首次发现木香抑制肠运动与拮抗气体信号分子合成酶抑制剂作用有关，推断内源性气体信号分子的生成可能参与木香对胃肠功能的调节；尚发现木香对化疗药所致肠粘膜损伤具有极强的保护作用，而这种保护作用是否与内源性气体信号分子存在相关性未见报道。稳定的气体信号分子水平及其合成酶表达对胃肠道粘膜保护起至关重要的作用，而“气体信号分子三驾马车”理论认为气体信号分子一氧化氮、一氧化碳及硫化氢作为整体在发挥作用，此与中医药整体治疗理念相吻合。我们认为中药发挥作用亦非对单一一种气体信号分子产生调节，而是整个体系共同作用的结果，对此目前尚未有研究证实。本项目将“气体信号分子三驾马车”的理论首次引入中药胃肠粘膜保护作用机制研究，通过PK-PD模型探讨木香及主要成分对肠粘膜保护作用与气体信号分子整体调控体系的相关性，为中医药胃肠粘膜保护作用研究提供新的理论和方法。

通过小鼠腹腔注射 5-FU造成肠黏膜损伤模型，实验组灌胃给予木香提取物及木香烃内酯及去氢木香内酯，通过对实验动物的饮水量、进食量、体重、腹泻及肠屏障功能等指标的观测，评价其对 5-FU 引起肠黏膜损伤的保护作用，并探讨作用机制。木香甲醇提取物对 5-FU 引起的肠黏膜损伤具有保护作用，主要是通过抑制氧化应激途径、炎症途径和免疫调节途径等。木香烃内酯和去氢木香内酯对肠道屏障功能的改善主要表现在其促进了肠上皮细胞的增殖功能，增加紧密连接蛋白的表达。木香烃内酯和去氢木香内酯主要通过抑制氧化应激途径、炎症途径发挥胃肠黏膜保护作用。在氧化应激途径中，木香烃内酯和去氢木香内酯抑制了丙二醛的表达，上调了超氧化物歧化酶的含量。在炎症途径中，木香烃内酯和去氢木香内酯给药后抑制了5-FU诱导的核转录因子、肿瘤坏死因子和前列腺素环氧合酶的表达上调， 降低了诱导性一氧化氮合成酶和一氧化氮的含量，促进了抗炎因子白介素的增加。木香中主要化学成分对炎症抑制作用，奠定了其作为一个胃肠黏膜保护剂的物质基础。.且对木香胃黏膜损伤保护作用进行研究，木香甲醇提取物抑制90%乙醇引起的胃溃疡，修复受损的胃黏膜，提高胃溃疡小鼠血浆中超氧化物歧化酶活性，抑制丙二醛含量，减少乙醇导致氧化损伤；同时能显著抑制溃疡小鼠血浆中核转录因子、一氧化氮和胃黏膜组织中的环氧化酶-2的过度表达，并提高血浆中抗炎因子白介素-10的释放，平衡炎症反应，减少乙醇的炎症损伤。木香烃内酯（Co）和去氢木香内酯（De）对乙醇诱导的胃损伤均具有抑制作用， Co对胃溃疡的抑制作用强于De。机制研究结果显示Co和De能提高小鼠血浆中SOD活力，抑制MDA、NF-κB、肿瘤坏死因子、COX-2、诱导型一氧化氮合酶等损伤介质的释放，并促进IL-10的分泌发挥黏膜保护作用；且Co的抗氧化及抗炎能力较强，这可能是其具有较强抗溃疡活性的原因之一。