灵芝多糖粗提物对雌二醇诱导小鼠胸腺萎缩的改善作用研究

孙嫣 范新 王刚 朱韵辰

摘 要 目的：研究灵芝多糖粗提物对雌二醇诱导小鼠胸腺萎缩的改善作用。方法：将60只雌性ICR小鼠随机分为正常对照组（生理盐水）、模型组（生理盐水）和灵芝多糖粗提物高、低剂量组（400、100 mg/kg，以生药量计），每组15只。除正常对照组外，其余各组小鼠均隔天腹腔注射雌二醇（0.1 mg/只，共6次）建立胸腺萎缩模型。造模结束后次日，小鼠灌胃给药，每天1次，连续给药14 d。末次给药24 h后，测定小鼠脏器（胸腺、脾）指数以及血浆中丙二醛（MDA）含量和谷胱甘肽S-转移酶（GST）活性，采用苏木精-伊红染色法观察小鼠胸腺、脾组织的病理学变化，采用原位末端标记法检测小鼠胸腺细胞凋亡情况，并采用流式细胞术检测其外周血中T细胞亚群分类。结果：与正常对照组比较，模型组小鼠胸腺指数和外周血中CD3+CD4+T细胞比例、CD4+/CD8+T比值均显著降低（P<0.01），脾指数、血浆中MDA含量、胸腺细胞凋亡水平以及外周血中CD3+CD8+T细胞比例均显著升高（P<0.05或P<0.01）;小鼠胸腺皮质和髓质分界模糊、细胞间隙增大、皮質出现部分细胞损伤凋亡，脾组织未见明显病理学变化。与模型组比较，灵芝多糖粗提物高剂量组小鼠胸腺指数、血浆中GST活性以及外周血中CD3+CD4+T细胞比例、CD4+/CD8+比值均显著升高（P<0.05或P<0.01），血浆中MDA含量、胸腺细胞凋亡水平显著降低（P<0.05或P<0.01），且胸腺组织病理学变化明显改善;灵芝多糖粗提物低剂量组小鼠仅血浆中MDA含量显著降低（P<0.01），其余指标/病理学变化均不明显。结论：高剂量（400 mg/kg）灵芝多糖粗提物对雌二醇诱导的小鼠胸腺萎缩具有一定的改善作用。

关键词 灵芝多糖粗提取;雌二醇;胸腺萎缩;免疫调节;小鼠

ABSTRACT OBJECTIVE： To study the improvement effects of Ganoderma lucidum polysaccharides crude extract on estradiol-induced thymus atrophy in mice. METHODS： Totally 60 female ICR mice were randomly divided into normal control group （normal saline）， model group （normal saline）， G. lucidum polysaccharides crude extract high-dose and low-dose groups （400， 100 mg/kg， by crude drug）， with 15 mice in each group. Except for normal control group， other groups were given estradiol intraperitoneally （0.1 mg/mice， 6 times） every other day to establish thymic atrophy model. The next day after modeling finished， they were given relevant medicine intragastrically， once a day， for consecutive 14 d. Twenty-four hours after last medication， organ （thymus， spleen） index， MDA content and GST activity in plasma were determined. HE staining was adopted to observe the pathological changes of thymus and spleen tissue in mice. The thymus cell apoptosis was examined by TUNEL assay， and the T cell subsets in peripheral blood were detected by flow cytometry. RESULTS： Compared with normal control group， the thymus index， proportion of CD3+CD4+T cell in peripheral blood and CD4+/CD8+ ratio were decreased significantly in model group （P<0.01）; spleen index， MDA content in plasma and thymocyte apoptosis level as well as the proportion of CD3+CD8+T cell in peripheral blood were all increased significantly （P<0.05 or P<0.01）. Thymic cortex and medullary boundary of mice was blurred; the intercellular space was enlarged; some cells were damaged and apoptotic in cortex; no pathological changes were found in the spleen. Compared with model group， thymus index and GST activity in plasma as well as proportion of CD3+CD4+T cell in peripheral blood and CD4+/CD8+ ratio were all increased significantly in G. lucidum polysaccharides crude extract high-dose group （P<0.05 or P<0.01）; while MDA content in plasma， the apoptosis level of thymocytes were all decreased significantly （P<0.01 or P<0.05）; and the pathological changes of thymus were improved significantly. MDA content in plasma was decreased significantly in G. lucidum polysaccharides crude extract low-dose group （P<0.01）， and other indexes/pathological changes were not obvious. CONCLUSIONS： High dose （400 mg/kg） of G. lucidum polysaccharides crude extract can improve the thymus atrophy induced by estradiol in mice.

KEYWORDS Ganoderma lucidum polysaccharide crude extract; Estradiol; Thymus atrophy; Immunomodulation; Mice

灵芝多糖（Ganoderma lucidum polysaccharides）为名贵中药材灵芝的主要药效成分之一，其种类繁多，结构复杂，分子量从几百到几十万不等，到目前为止，被人们发现的灵芝多糖已经超过200种[1]。灵芝多糖主要来源为灵芝子实体多糖、发酵液多糖以及液体发酵产生的菌丝体多糖[2]。灵芝多糖作为一种有效免疫调节剂，能够全面且有效地影响免疫细胞（包括T淋巴细胞、巨噬细胞、B淋巴细胞等）的功能，同时释放趋化因子、生长因子，从而调节机体的适应性免疫[3]，其调节机体免疫力的功效已成为研究热点[4]。胸腺作为免疫系統重要的中枢器官，与机体的健康息息相关。……