当归红芪超滤物对衰老大鼠脑组织氧化损伤及线粒体DNA缺失的影响

摘要

目的：探讨当归红芪超滤物延缓老龄大鼠脑衰老的作用及其机制。方法选用3月龄大鼠12只作为青年组，选用24月龄大鼠36只随机分为老年组、当归红芪超滤物组、维生素E组。给予相应处理后检测各组学习记忆功能、脑指数测定，组织形态学观察，脑组织中超氧化物歧化酶（ SOD）活力，丙二醛（ MDA）含量测定及脑组织线粒体DNA（ mt-DNA）缺失的表达。结果与青年组大鼠相比：老年组大鼠学习能力下降，脑组织形态学存在差异，脑指数存在差异（P＜0.05），脑组织 SOD活力明显降低，MDA 含量明显升高，脑缺失 mt-DNA／内参 mt-DNA 比例明显增高（P＜0.05）；与老年组相比：用药组大鼠学习能力明显增加，脑组织形态学存在差异，脑指数无明显差异，脑组织中SOD 活力显著增高，脑组织中 MDA 含量显著降低，脑缺失mt-DNA／内参mt-DNA比例降低（ P＜0.05）。与维生素E组相比，用药组大鼠学习能力、脑指数、脑组织 SOD 活力、MDA含量、脑缺失mt-DNA／内参mt-DNA比例均无显著差异（ P＞0.05）。结论当归红芪超滤物可能通过清除自由基，防止mt-DNA片段丢失发挥延缓老龄大鼠脑组织衰老的作用，其功效与维生素E相当。%Objective To investigate the effect of ultra-filtration extract from Angelica sinensis and Hedysari Polybotrys ( UFE-AH) on slowing brain aging of old rats .Methods 12 healthy male Wistar rats of 3-months old were selected for the youth control group ,and 36 natural aging male Wistar rats of 24-months old were selected and randomly divided into three groups:the old control ,UFE-AH and Vitamin E (VE) groups.After above treatments,the learning and memory ability and the brain index of each group of Wistar rats were measured ,brain tissue(hippocampus and cortex) was observed by microscope,the activity of dismutase(SOD),contents of maloudialdehyde(MDA) and the expression of mitochondrial DNA ( mt-DNA) deletion in the brains were tested .Results The learning and memory ability of old rats de-creased compared with the youth rats , there were significant difference in the brain tissue and brain index between the old and the youth (P<0.05).The activity of SOD apparently decreased ,contents of MDA apparently increased ,and the expression of mt-DNA deletion in-creased in old rats(P<0.05).Rats treated with UFE-AH had high learning and memory ability compared with the normal old rats ,there were significant difference in the brain tissue ,and there was no difference in brain index .The activity of SOD apparently increased ,contents of MDA apparently decreased,and the expression of mt-DNA deletion decreased of rats treated with UFE-AH(P<0.05).Rats treated with UFE-AH had no significant differences with the rats treated with VE in above parameters .Conclusions The UFE-AH could slow brain ag-ing of old rats by eliminating free oxygen radicals and preventing from mt-DNA deletion,whose function is similar with the VE .