基于线粒体结构与功能的改变探讨猴头菌均一多糖对脾虚型溃疡性结肠炎大鼠干预机制

Recently, in China the incidence of ulcerative colitis has increased yearly, and the patients’ risk of cancer is very high. Chinese medicine has outstanding advantages for the disease, and ulcerative colitis with spleen deficiency is the most common type in diagnosis of TCM. But the mechanism remains unclarified. The previous studies on Chinese medicine of the disease were limited to the compound decoctions, lacking of deep researches of monomer composition,single Chinese herb and the its mechanism.Polysaccharide of Hericium erinaceus has many biological activities.And its anti ulcerative colitis activity is very exact. But the studies on homogeneous polysaccharide were less, on the mechanism were not deep enough. Before the project we screened and purified a homogeneous polysaccharide. On the basis of he definite chemical structure, the polysaccharide showed good activity on ulcerative colitis in spleen deficiency’s rats preliminarily, and the polysaccharide can inhibit the apoptosis through mitochondrial pathway. In summary, the project intends to use the pre-prepared homogeneous polysaccharide of Hericium erinaceus, confirming its activity from the anti-inflammatory, anti-antioxidant, immunomodulatory aspects. Then, We will revolve around the mitochondria related aspects: the change of energy metabolism and respiratory function, ultrastructure, the change of membrane potential and apoptosis protein of expressions mitochondrial pathways to discuss the intervention mechanism of Hericium erinaceus polysaccharide on spleen deficiency with ulcerative colitis in rats .The study will provide new ideas for prevention and treatment of ulcerative colitis by using Chinese medicine.

近年，我国溃疡性结肠炎的发病率逐年上升，患者癌变风险极高。中医药治疗该病优势明显，脾虚型溃疡性结肠炎是中医诊断中最常见类型，但机制不明。以往中医药治疗该病的研究多限于复方，对单味中药、单体成分及其作用机制缺乏深层次探讨。猴头菌多糖具有多种生物活性，抗溃疡性结肠炎活性确切。但是对均一多糖的活性及机制研究较少。项目前期筛选并制备了猴头菌均一多糖，在明确化学结构的基础上确认了其对大鼠脾虚型溃疡性结肠炎的活性，发现其活性与减少线粒体途径的细胞凋亡有关。大量研究表明线粒体结构与功能的改变与脾虚及溃疡性结肠炎的发生密切相关。故本项目拟利用前期制备的猴头菌均一多糖，从抗炎、抗氧化、免疫调节方面确认其活性；再围绕线粒体相关的能量代谢和呼吸功能的改变、超微结构和膜电位的改变及线粒体途径的细胞凋亡蛋白的表达等方面探讨猴头菌多糖对脾虚型溃疡性结肠炎大鼠干预机制，为溃疡性结肠炎的中医药预防和治疗提供新的思路。

猴头菌是我国传统药用菌类，具有多种生理功能，包括抗胃肠道溃疡，抗消化道癌症、免疫调节等活性。临床研究及动物试验表明其治疗溃疡性结肠炎疗效明显，但活性组分不明确，作用机制不清楚。本项目建立了脾虚型溃疡性结肠炎动物模型和细胞模型、筛选并制备了猴头菌均一多糖，明确化学结构、确认了其对大鼠脾虚型溃疡性结肠炎的活性。并从线粒体结构和功能的改变为基础深入研究其活性机制。实验结果表明上述纯化的猴头菌多糖中性糖含量达95.7%，分子量为3.1K Da，甘露糖：葡萄糖：半乳糖组成比例为4:94:2。甲基化分析可知猴头菌多糖-1以1→3连接的葡萄糖为主链；动物试验表明在高剂量猴头菌多糖治疗组较模型组比较，结肠黏膜充血减少，上皮皱褶基本恢复正常。血清的Elisa检测结果表明猴头菌多糖通过刺激抗氧化酶活性和抑制脂质过氧化来保护溃疡性结肠炎大鼠结肠组织的氧化应激，随着氧化应激的缓解，大鼠血清中TNF-α、IL-6和IL-8的炎症因子分别显著降低；进一步研究结果表明猴头菌多糖能够恢复溃疡性结肠炎大鼠结肠线粒体结构的完整性，提高线粒体膜电位和呼吸功能，增加结肠组织中ATP的含量。动物模型及细胞模型均证明猴头菌多糖能通过线粒体途径减少氧化因子引起的结肠黏膜细胞凋亡。本项目的完成将对猴头菌均一多糖多种活性共同起效抗脾虚型溃疡性结肠炎活性研究提供一定的科研思路。另外，基于线粒体结构及功能的改变研究中药对脾虚型溃疡性结肠炎的干预机制将为中医治疗该病提供更为详实可靠的现代医学证据，同时对于中药研发、提升传统中药的科技含量及为溃疡性结肠炎提供科学的诊断依据和安全有效的治疗手段都将具有重要的意义。