益智仁水提取物对脑缺血大鼠记忆障碍的改善作用

Effect of water extracts of Alpinia oxyphylla Miq. fruit on memory impairment in cerebral ischemia rats

目的探讨益智仁水提取物（AOF）对脑缺血大鼠学习记忆能力的改善作用及其作用机制。方法48只健康成年雄性SD大鼠随机分成4组：假手术组、脑缺血组、AOFI组、AOF1I组，每组12只。除假手术组外，其余各组大鼠均采用双侧颈总动脉反复夹闭再灌注同时腹腔注射硝普钠降压方法建立脑缺血动物模型。避暗实验测定大鼠学习记忆能力，同时测定海马一氧化氮（NO）含量及一氧化氮合酶（NOS）活力。结果避暗实验中，脑缺血组大鼠的潜伏期[（143．8±65．2）s]显著短于假手术组[（257．2±67．1）s]（P〈0．01），错误次数[（8．9±4．2）次]显著多于假手术组[（1．7±1．1）次]（P〈0．01）；而AOFI、Ⅱ组的潜伏期[（186．5±46．2）s，（193．4±43．7）S]显著长于脑缺血组（P〈0．05），错误次数[（6．1±2．9）次，（5．2±2．1）次]显著少于脑缺血组（P〈0．05，P〈0．01）。脑缺血组海马NO含量及NOS活力[（56．53±27．42）nmol/mg prot，（17．23±5．64）nmol／mg prot]显著高于假手术组[（40．02±17．9）nmol／mgprot，（10．46±6．15）nmol／mg prot]；而AOFⅠ、Ⅱ组海马NO含量及NOS活力[NO含量：Ⅰ组（46．60±20．26）nmolfmgprot，Ⅱ组（42．38±21．23）nmolfmgprot；NOS活力：Ⅰ组（13．98±5．13）nmol／mgprot，Ⅱ组（13．614-5．27）nmolfmgprot]显著低于脑缺血组（P〈0．05）。结论AOF可显著改善脑缺血所致大鼠记忆障碍，其机制可能与降低海马NO含量及NOS活力有关。

Objective This report investigate the intervention effect of the water extract of Alpinia oxyphylla Miq. fruit （AOF）on memory impairment and the mechanism in cerebral ischemia rats. Methods 48 Rats were randomly divided into sham-operated group（ n= 12）, ischemia group（ n= 12）, AOF group Ⅰ（ n= 12） and AOF group Ⅱ （ n= 12）. The model of transient cerebral ischemic/reperfusion was made by bilateral occlusion of common carotid arteries in rats and combination with reducing blood pressure with an abdominal injection of sodium nitroprusside. Learning-memory ability was observed by step through test. The content of NO and the activities of NOS were measured in hippocampus. Results In step through test,the latency in iscbemia group[ （ 143.8 ± 65.2）s] significantly decreased, the number of errors （8.9 ±4.2 ）significantly increased compared with shamoperated group [ latency ： （257.2 ± 67.1 ） s ; number of errors： （ 1. 7 ± 1.1 ）, P 〈 0.01 ]. The latency in AOF group Ⅰ and AOF group Ⅱ [ （ 186.5 ± 46.2 ） s, （ 193.4 ± 43.7 ） s ] significantly increased, the number of errors （ 6.1 ± 2.9,5.2 ± 2.1 ） significantly decreased compared with ischemia group （P 〈 0. 05, P 〈 0.01 ）. In hippocampus, the content of NO and the activities of NOS in ischemia group [ （ 56.53 ± 27.42 ） nmol/mg prot, （ 17.23 ± 5.64 ） nmol/ mg prot ] significantly increased compared with sham-operated group [ （40.02 ± 17.9 ） nmol/mg prot, （ 10.46 ± 6.15 ） nmol/mg prot ], and in AOF group Ⅰand AOF group Ⅱ [ content of NO ： group Ⅰ（46. 60 ± 20.26 ） nmol/mg prot, group Ⅱ （ 42.38 ± 21.23 ） nmol/mg prot ; activities of NOS ： group Ⅰ （ 13.98 ± 5.13 ） nmol/mg prot, group Ⅱ （ 13.61 ± 5.27 ） nmol/mg prot] significantly decreased compared with ischemia group（P〈 0.05 ）. Conclusion AOF could significantly ameliorate the memory impairment in cerebral ischemic rats. Its effects may be involved in the decrease of content of NO and activities of NOS in hippocampus.