硫辛酸对大鼠脑氧化损伤保护作用

Protective effect of lipoic acid on rat brain homogenate and its mechanism in vitro

目的探讨硫辛酸(LA)在体外对过氧化氢(H2O2)引起大鼠脑氧化损伤的保护作用。方法新鲜的大鼠脑匀浆分为LA组和LA+H2O2组;LA组在脑匀浆中分别给予不同浓度的LA;LA+H2O2组在脑匀浆中给予上述各浓度的LA同时加入终浓度100μmol/H2O2,上述反应作用1h后测定大鼠脑匀浆中脂质过氧化产物丙二醛(MDA)和谷胱甘肽(GSH)的含量。结果与对照组(LA和H2O2浓度均为0)比较,100μmol/LH2O2能使脑匀浆MDA含量增加到(11.85±0.83)μmol/(g.pro),GSH含量下降到(21.2l±4.91)μmol/(g.pro),差异均有统计学意义(P<0.05);与模型组(单独给予100μmol/LH2O2)比较,同时加入100～300μmol/LLA可使MDA含量平均下降20.2%～28.1%,GSH含量平均升高50.1%～63.3%,差异均有统计学意义(P<0.05)。结论一定浓度LA对H2O2引起的大鼠脑组织氧化损伤有明显的保护作用,可能与提高其GSH含量,降低MDA含量有关。

Objective To study the protective effect and mechanism of lipoic acid （LA）on oxidative damage of rat brain homogenate induced by H202. Methods Fresh rat brain homogenates were divided into LA group and LA ＋ H2O2 group. The rat brain homogenate of LA groups was treated with 0,100,200 and 300 μmol/L LA and the rat brain homoge- hate of LA ＋H202 grous was treated with 100 μmol/L H202 and 0,100,200 and 300μmol/L LA,respectively. The treat- ment time was one hour. The levels of MDA and GSH were measured. Results 100 I.Lmol/L H202 increased the level of MDA to 11.85 ＋0. 83 μmol/（g-pro）. The levels of GSH was decreased to 21.21 ＋4. 91 μmol/（g-pro） compared with that of the control（ P 〈0.05）. 1 00 - 300 txmot/L LA could decreased the level of MDA from 20.2 to 28.1 percent. The level of GSH increased from 50.1 to 63. 3 percent compared with 100 taznol/L H202group with significant difference（P 〈 0.05 ）. Conclusion A cetain level of LA can inhibit significantly the oxidative damage of rat brain homogenate induced by H2O2. Its mechansm may be the increase of GSH level and decrease of MDA level through the role of elevation GSH level.