褪黑素拮抗鼠肝线粒体自由基产生的实验研究

Experimental study on how melatonin antagonises free radical production in rat liver mitochondiral membrane

目的观察褪黑素拮抗氧自由基和对膜脂质过氧化损伤的保护作用。方法用电子自旋共振技术，以ＤＭＰＯ和４－ＰＯＢＮ为捕集剂，捕集Ｆｅｎｔｏｎ反应产生的羟自由基和Ｆｅ２＋启动的鼠肝线粒体膜脂质过氧化产生的脂类自由基，以脂肪酸自旋标记物５－Ｄｏｘｙｌ和１６－Ｄｏｘｙｌ标记线粒体膜，研究脂质过氧化损伤后膜流动性的变化。结果褪黑素对羟自由基和脂类自由基有良好的清除作用，５０％清除浓度分别为１８６μｍｏｌ·Ｌ－１和４５０μｍｏｌ·Ｌ－１，而且在５００μｍｏｌ·Ｌ－１浓度范围内能防止脂质过氧化引起的线粒体膜流动性降低。结论褪黑素是一个有效的抗氧化剂，能防止生物膜的脂质过氧化损伤。

AIM To observe the effect of melatonins antagonism against oxygen free radical and protection biomembrane from lipid peroxidation damage. METHODS Using the ESR technique, DMPO and 4POBN as spintrapping traped hydroxyl radical in Fenton reaction and lipids radical generated from the lipid peroxidation of the mitochondrial membrane induced by ferrous. Lipidspecific spin labels 5Doxyl and 16Doxyl as lebeling probes lebeled mitochondrial membrane to study the change of mitochondrial membrane fluidity. RESULTS The results showed that melatonin has an effective scavenging effect on hydroxyl radical and lipids free radical. The IC50 was 186 μmol·L-1 and 450 μmol·L-1. Melatonin could prevent membrane fluidity decrease from lipid peroxidation damage. CONCLUTION Melatonin is an effective antioxidant which can protect biomembrane from lipid peroxidation damage.