目的:探讨黄精对AD模型大鼠空间学习记忆能力及前额叶皮质和海马α7 n AChR表达的影响。方法:成年雄性SD大鼠随机分为四组:对照组、模型组、黄精低剂量组、黄精高剂量组。皮下注射D-半乳糖联合双侧海马注射Aβ25-35构建AD模型大鼠,黄精...目的:探讨黄精对AD模型大鼠空间学习记忆能力及前额叶皮质和海马α7 n AChR表达的影响。方法:成年雄性SD大鼠随机分为四组:对照组、模型组、黄精低剂量组、黄精高剂量组。皮下注射D-半乳糖联合双侧海马注射Aβ25-35构建AD模型大鼠,黄精低、高剂量组同时每天分别给予低剂量(15 g/kg/d)或高剂量(30g/kg/d)的黄精水煎剂灌胃治疗,连续6周。Morris水迷宫测试大鼠的空间学习和记忆能力;免疫组织化学技术检测大鼠前额叶皮质和海马α7 n AChR的表达。结果:Morris水迷宫结果显示,模型组大鼠的逃避潜伏期(EL)与对照组相比明显延长(P<0.01),在目标象限游泳时间和穿越站台次数减少(P<0.01);与模型组比较,黄精低剂量组、高剂量组的EL缩短(P<0.01),在目标象限游泳时间和穿越站台次数增多(P<0.01);黄精高剂量组的EL较低剂量组缩短(P<0.05或P<0.01),在目标象限游泳时间和穿越站台次数差异无统计学意义(P>0.05)。免疫组化结果显示,模型组大鼠前额叶皮质和海马α7 n AChR表达水平较对照组明显降低(P<0.01);黄精低剂量组、高剂量组大鼠前额叶皮质和海马α7n AChR表达水平较模型组明显上调(P<0.05或P<0.01);黄精高剂量组大鼠α7 n AChR表达水平较低剂量组大鼠增多(P<0.05)。结论:黄精可以明显改善AD模型大鼠的空间学习记忆能力,其作用机制可能与调节α7 n AChR表达有关。展开更多
Objective To investigate the neuroprotective action of astragaloside Ⅳ(AS-Ⅳ) on spatial learning and memory impairment induced by amyloid-beta 1-42(Aβ1-42) in rats and elucidate its underlying molecular mechanisms....Objective To investigate the neuroprotective action of astragaloside Ⅳ(AS-Ⅳ) on spatial learning and memory impairment induced by amyloid-beta 1-42(Aβ1-42) in rats and elucidate its underlying molecular mechanisms.Methods Adult-male Sprague-Dawley rats(230-250 g) were divided into six groups randomly: control, Aβ1-42, AS-Ⅳ, Aβ1-42 plus 5 mg/kg·d AS-Ⅳ, Aβ1-42 plus 25 mg/kg·d AS-Ⅳ, and Aβ1-42 plus 50 mg/kg·d AS-Ⅳ groups. Aβ1-42 were delivered by intracerebroventricular injection under the guidance of a brain stereotaxic apparatus. The Morris water maze test(hidden platform test, probe trials, visible platform test) was performed one week after Aβ1-42 injection to obtain the ability of rat spatial learning and memory. AS-Ⅳ(5, 25 and 50 mg/kg·d) was administrated intraperitoneally once per day from the 8 th day after Aβ1-42 injection for 5 consecutive days. Average escape latencies, distances for searching for the platform under water and the percentage of total time elapsed and distance swam in the right quadrant after removing platform were determined by behavior softwaresystem. The vision and swim speeds of rats were also determined to exclude the effect of these factors on the parameters of learning and memory. After behavioral tests, the rats were sacrificed immediately by decapitation. Hippocampus were collected. The enzyme activities of superoxide dismutase(SOD), glutathione peroxidase(GSH-px) and catalase(CAT) in the hippocampus obtained from different-treated rat brain were measured by following the manufacturer’s instructions. The levels of interleukin-1 beta(IL-1β) and tumor necrosis factor-alpha(TNF-α) in tissue lysates were assayed with ELISA.Results The water maze test results indicated that chronic treatments with AS-Ⅳ effectively protected the rats from Aβ1-42-induced spatial learning and memory impairment. Furthermore, the activities of SOD, GSH-px and CAT decreased by Aβ1-42 were also restored by AS-Ⅳ treatment in the hippocampus of rats. In addition, AS-Ⅳ signi展开更多
文摘目的:探讨黄精对AD模型大鼠空间学习记忆能力及前额叶皮质和海马α7 n AChR表达的影响。方法:成年雄性SD大鼠随机分为四组:对照组、模型组、黄精低剂量组、黄精高剂量组。皮下注射D-半乳糖联合双侧海马注射Aβ25-35构建AD模型大鼠,黄精低、高剂量组同时每天分别给予低剂量(15 g/kg/d)或高剂量(30g/kg/d)的黄精水煎剂灌胃治疗,连续6周。Morris水迷宫测试大鼠的空间学习和记忆能力;免疫组织化学技术检测大鼠前额叶皮质和海马α7 n AChR的表达。结果:Morris水迷宫结果显示,模型组大鼠的逃避潜伏期(EL)与对照组相比明显延长(P<0.01),在目标象限游泳时间和穿越站台次数减少(P<0.01);与模型组比较,黄精低剂量组、高剂量组的EL缩短(P<0.01),在目标象限游泳时间和穿越站台次数增多(P<0.01);黄精高剂量组的EL较低剂量组缩短(P<0.05或P<0.01),在目标象限游泳时间和穿越站台次数差异无统计学意义(P>0.05)。免疫组化结果显示,模型组大鼠前额叶皮质和海马α7 n AChR表达水平较对照组明显降低(P<0.01);黄精低剂量组、高剂量组大鼠前额叶皮质和海马α7n AChR表达水平较模型组明显上调(P<0.05或P<0.01);黄精高剂量组大鼠α7 n AChR表达水平较低剂量组大鼠增多(P<0.05)。结论:黄精可以明显改善AD模型大鼠的空间学习记忆能力,其作用机制可能与调节α7 n AChR表达有关。
基金Supported by the Natural Science Foundation of Shaanxi Province of China(2015JQ8299)National Science Foundation of China(81703842)Traditional Chinese Medicine Scientific Research Projects of Shaanxi Province of China(JCMS032)
文摘Objective To investigate the neuroprotective action of astragaloside Ⅳ(AS-Ⅳ) on spatial learning and memory impairment induced by amyloid-beta 1-42(Aβ1-42) in rats and elucidate its underlying molecular mechanisms.Methods Adult-male Sprague-Dawley rats(230-250 g) were divided into six groups randomly: control, Aβ1-42, AS-Ⅳ, Aβ1-42 plus 5 mg/kg·d AS-Ⅳ, Aβ1-42 plus 25 mg/kg·d AS-Ⅳ, and Aβ1-42 plus 50 mg/kg·d AS-Ⅳ groups. Aβ1-42 were delivered by intracerebroventricular injection under the guidance of a brain stereotaxic apparatus. The Morris water maze test(hidden platform test, probe trials, visible platform test) was performed one week after Aβ1-42 injection to obtain the ability of rat spatial learning and memory. AS-Ⅳ(5, 25 and 50 mg/kg·d) was administrated intraperitoneally once per day from the 8 th day after Aβ1-42 injection for 5 consecutive days. Average escape latencies, distances for searching for the platform under water and the percentage of total time elapsed and distance swam in the right quadrant after removing platform were determined by behavior softwaresystem. The vision and swim speeds of rats were also determined to exclude the effect of these factors on the parameters of learning and memory. After behavioral tests, the rats were sacrificed immediately by decapitation. Hippocampus were collected. The enzyme activities of superoxide dismutase(SOD), glutathione peroxidase(GSH-px) and catalase(CAT) in the hippocampus obtained from different-treated rat brain were measured by following the manufacturer’s instructions. The levels of interleukin-1 beta(IL-1β) and tumor necrosis factor-alpha(TNF-α) in tissue lysates were assayed with ELISA.Results The water maze test results indicated that chronic treatments with AS-Ⅳ effectively protected the rats from Aβ1-42-induced spatial learning and memory impairment. Furthermore, the activities of SOD, GSH-px and CAT decreased by Aβ1-42 were also restored by AS-Ⅳ treatment in the hippocampus of rats. In addition, AS-Ⅳ signi
