北五味子乙素对大鼠离体心肌缺血再灌注损伤的保护作用及分子机制

目的：观察北五味子乙素（schisandrin B,SchB）对缺血再灌注（ischemia/reperfusion,I/R）大鼠离体心脏功能、梗死面积、乳酸脱氢酶及相关蛋白表达的影响,探讨其对I/R损伤的保护作用及分子机制。方法：Wistar大鼠50 只,随机分为5 组：空白对照组（CON）、缺血再灌注组（I/R）、SchB预保护组（SchB）、PI3K抑制剂组（I/R＋SchB＋LY）、腺苷酸活化的蛋白激酶（AMP-activated protein kinase,AMPK）抑制剂组（I/R＋SchB＋CC）。采用Langendorff法建立离体大鼠心脏I/R模型,心肌缺血2 h,再灌注5、15、30、60 min。观察I/R期间室内压最大上升速率（＋dp/dtmax）、室内压最大下降速率（－dp/dtmax）、左心室舒张末压、冠脉流量和心率;测定心脏灌流液中乳酸脱氢酶（lactate dehydrogenase,LDH）含量,2,3,5-氯化三苯基四氮唑（2,3,5-triphenyltertrazoliumchloride,TTC）染色测定各组心肌梗死面积;免疫印迹检测心肌中总蛋白激酶B（protein kinase B,PKB）、磷酸化Akt（p-Akt）、总糖原合成酶激酶-3β（glycogen synthease kinase-3β,GSK-3β）、磷酸化GSK-3β（p-GSK-3β）蛋白表达。结果：SchB可显著改善I/R所致的心肌功能损伤,减少梗死面积,提高心肌中p-Akt和p-GSK-3β蛋白表达。结论：SchB对大鼠离体心脏I/R损伤具有一定保护作用,其机制可能与激活AMPK和PI3K/Akt信号通路有关。     

Augmentation of polysialic acid by valproic acid in early postnatal mouse hippocampus and primary cultured hippocampal neurons

We examined the effects of valproic acid (VPA) on hippocampal neurons. Prenatal VPA exposure significantly increased polysialic acid (PSA) expression in the early postnatal mouse hippocampus. Moreover, VPA treatment significantly enhanced PSA expression in primary cultured hippocampal neurons and stimulated neurite growth. Our results suggest that VPA exposure in ovo affects hippocampal development.     

五味子乙素对D-半乳糖致衰老小鼠学习记忆能力的改善作用

目的：观察五味子乙素（schisandrin B,SCB）对D-半乳糖致衰老小鼠学习记忆能力的改善作用。方法：ICR小鼠随机分为4 组,即正常对照组（灌胃蒸馏水,皮下注射生理盐水）、衰老模型组（灌胃蒸馏水,皮下注射220 mg/kg D-半乳糖）、SCB（M）组（灌胃20 mg/kg SCB,皮下注射D-半乳糖220 mg/kg）、SCB（C）组（灌胃20 mg/kg SCB,皮下注射生理盐水）,连续给药7 周。通过避暗实验及Morris水迷宫实验观察SCB对小鼠学习记忆能力的影响;通过WST-1法检测小鼠脑组织中超氧化物歧化酶（superoxide dismutase,SOD）活力;通过硫代巴比妥酸法检测小鼠脑组织中丙二醛（malondialdehyde,MDA）含量;通过实时定量聚合酶链式反应及Western blot法,检测小鼠脑组织中p19、p53、p21基因表达情况。结果：SCB能够明显改善D-半乳糖诱导的脑衰老小鼠的学习记忆能力,提高脑衰老小鼠脑组织中SOD活力,降低MDA水平,明显降低脑组织中的p19、p53、p21基因的表达水平。结论：SCB能够改善D-半乳糖诱导的小鼠脑衰老,该作用可能与其提高小鼠抗氧化能力及下调小鼠脑组织中p19、p53、p21基因表达水平有关。     

白首乌酒对癫痫大鼠神经元保护作用及其机制研究

为了优化苹果酵素自然发酵工艺,通过Box-Behnken试验设计,研究初始pH值、糖添加量、苹果片质量浓度对苹果酵素感官评分和超氧化物歧化酶（SOD）活性的影响,并采用超高效液相色谱（UPLC）及液相色谱-质谱联用技术（LC-MS）分析了酚类物质的组成和含量。结果表明,优化出自然发酵工艺条件为初始pH值4.6,糖添加量15%,苹果片含量200 g/L。在此优化条件下,苹果酵素感官评分为（8.45±0.24）分、SOD活性为（40.26±1.03） U/mL。苹果酵素共检测出15种酚类物质,其中绿原酸含量最高,原花青素B2、表儿茶素、原花青素B1、槲皮素-半乳糖苷、儿茶素以及根皮苷次之。     

Effects of long-chain fatty acids on cytosolic triacylglycerol accumulation and lipid droplet formation in primary cultured bovine mammary epithelial cells

Mammary epithelial cells have recently been shown to express and secrete leptin into milk and to accumulate triacylglycerol (TAG) in cytosol. We examined the effects on the accumulation of cytosolic TAG of free fatty acid addition to the medium bathing bovine mammary epithelial cells (bMEC). Both saturated (palmitic and stearic) and unsaturated (oleic and linoleic) fatty acids stimulated the accumulation of TAG in a concentration-dependent manner from 50 to 400 microM and the expression of mRNA expression for CD36, which is involved in the uptake and secretion of long-chain fatty acids. However, leptin mRNA expression and lipid droplet formation were significantly increased only by the addition of unsaturated, but not saturated, fatty acids. Interestingly, both types of fatty acids stimulated alphas1-casein mRNA expression. These data suggest that the expression of leptin is related to droplet formation, whereas CD36 is related to cytosolic TAG accumulation, and that fatty acids or cytosolic TAG accumulation also have a role to accelerate differentiation of bMEC as shown by casein synthesis.