中文摘要：

目的：检测大蒜多糖对大鼠嗜铬瘤细胞株（pheochromocytoma cells，PCI2）增殖的影响和对经过氧化氢（H2O2）诱导损伤的PCI2细胞的保护作用。方法：应用四氮唑蓝（MTT）比色法检测大蒜多糖对细胞增殖的影响；建立H2O2致PCI2细胞损伤模型，于倒置相差显微镜下观察细胞形态的变化；化学比色法测定乳酸脱氢酶（LDH）释放量及细胞内和细胞培养上清液中丙二醛（MDA）含量和超氧化物歧化酶（SOD）的活性。结果：大蒜多糖各剂量组均能显著提高正常PCI2细胞的存活数，大蒜多糖各剂量组均能有效对抗由25μmol／LH2O2引起的细胞存活率下降和细胞凋亡，可明显改善细胞形态的衰变，显著降低LDH释放量和细胞培养液及细胞内的MDA含量，提高SOD活性。结论：大蒜多糖促进正常PC12细胞增殖；且对H2O2诱导PC12细胞损伤具有保护作用，其作用机制可能与提高PC12细胞的抗氧化能力有关。

英文摘要：

Aim：To study the effect of garlic polysaccharide on cell proliferation and its protective effect on pheochromocytoma cells injury induced by hydrogen peroxide. Methods： MTT assay for cell proliferation, the model that H2O2 induced injury in PC12 cells was generated. Morphological changes of PC12 cells were observed under reversal phase microscope. Lactate dehydrogenase （LDH） , malondialdelyde （MDA） and superoxide dismutase （SOD） in the culture medium and MDA, SOD in cells were measured by spectroscopy respectively. Results： Garlic polysaccharide with different concentrations could promote the cell proliferation of PC12. It could resist the decrease in the cell viability and increase in the apoptotic rate induced by 25 μmol/L H2O2. After exposed to 25 μmol/L H2O2 for 4 h, typical morphological characteristics of cells injury were observed. Both LDH and MDA levels increased significantly, while SOD level decreased significantly in HEO2 induced group compared with those in the sham group. Garlic polysaccharide could decrease LDH and MDA content and increase SOD level significantly. Conelusion：Gadic polysaccharide stimulates the proliferation of PC12; and it has protective effect on PC12cells injury induced by hydrogen peroxide in culture, which may be related to enhancing the antioxidant abilites of PC12.