甘糖酯抗氧化作用的分子机制

Molecular mechanisms of antioxidant effects of propylene glycol mannate sulfate

目的 探讨甘糖酯 (PGMS)清除自由基抗氧化作用的分子机制。方法 给大鼠ig高脂乳剂建立高脂血症模型 ,分成对照组、甘糖酯治疗组、甘糖酯 +DDC组 ,治疗 3周。检测血清、肝脏、脾脏和主动脉中丙二醛 (MDA)的含量 ,超氧化物歧化酶 (SOD)、谷胱甘肽过氧化物酶 (GSH Px)和过氧化氢酶 (CAT)的活性 ,以及Cu ,Zn SODmRNA的表达水平。结果 甘糖酯治疗组大鼠 ,丙二醛 (MDA)含量降低 ,SOD ,GSH Px和CAT的活性显著升高 ,Cu ,Zn SODmRNA的表达水平增加 ;而甘糖酯和DDC联合用药治疗组 ,DDC抑制了甘糖酯诱导的Cu ,Zn SODmRNA表达水平和SOD活性的升高 ,造成MDA含量的相应升高。结论 甘糖酯通过诱导抗氧化酶SOD ,GSH Px和CAT的活性 ,增加Cu ,Zn SODmRNA的表达水平 ,清除体内过多的氧自由基 ,达到抗氧化的目的。

Aim To investigate the antioxidant mechanisms of propylene glycol mannate sulfate (PGMS) in hyperlipidemic rats. Methods Male Wistar rats were given high lipid emulsion diet to establish hyperlipidemic model. PGMS was given every day at different doses (37 8 and 75 6 mg·kg -1 , ig) to hyperlipidemic rats for three weeks. In addition, diethyldithiocarbamate (DDC) was given 200 mg·kg -1 ·3d -1 (ip) to inhibit SOD activity. Then, the MDA content was examined using TBA method to show the oxidation level, and the activities of SOD, GSH Px and CAT were examined following the kit protocols to indicate the capability of eliminating OFR. RT PCR was applied to study the expression of Cu, Zn SOD mRNA in rat liver. Results The MDA content of PGMS treatment groups decreased markedly compared with hyperlipidemic group, and the activities of SOD, GSH Px and CAT increased distinctly. Cu, Zn SOD mRNA expression was significantly increased by PGMS treatment. Furthermore, the application of DDC(the SOD inhibitor) reduced total SOD activity and Cu, Zn SOD mRNA expression induced by PGMS, and the content of MDA increased correspondingly. Conclusion PGMS can induce the activities of antioxidant enzymes and the mRNA expression of Cu, Zn SOD, which contribute to the elimination of oxygen free radical. This may explain the molecular mechanism of antioxidant effects of PGMS.