穿心草口山酮抗氧化作用初探

目的以大鼠组织匀浆及ＲＢＣ为材料研究３种穿心草口山酮（ｘａｎｔｈｏｎｅ，Ｘａｎ）：１，８－ｄｉｈｙｄｒｏｘｙ３，５－ｄｉｍｅｔｈｏｘｙｘ－ａｎｔｈｏｎｅ（Ｘａｎ－Ⅰ）；１－ｈｙｄｒｏｘｙ，５－ｄｉｍｅｔｈｏｘｙｘａｎｔｈｏｎｅ（Ｘａｎ－Ⅱ）；１－ｈｙｄｒｏｘｙ，３，７，８－ｔｒｉｔｈｏｘｙｘａｎｔｈｏｎｅ（Ｘａｎ－Ⅲ）抗脂质过氧化作用。方法以ＭＤＡ为指标，观察Ｘａｎ对组织匀浆体外脂质过氧化及ＲＢＣ自氧化溶血体系脂质过氧化产物丙二醛（ＭＤＡ）生成量的影响；并观察Ｘａｎ对邻苯三酚自氧化产生的Ｏ·２及Ｃｕ２＋－ＶｉｔＣ自由基产生系统产生的·ＯＨ的清除作用。结果①０．０５μｍｏｌ·Ｌ－１的３种Ｘａｎ均可抑制正常大鼠脑、肝、心匀浆体外过氧化脂质生成，并能对抗半胱氨酸和硫酸亚铁所致过氧化脂质生成增加。②３种Ｘａｎ均能抑制ＲＢＣ自氧化，显著减少ＲＢＣ自氧化过程中ＭＤＡ的含量。③３种Ｘａｎ均能清除超氧阴离子自由基（Ｏ·２）和羟自由基（·ＯＨ），清除·ＯＨ的作用更强。④３种Ｘａｎ清除氧自由基的活性强弱顺序为Ｘａｎ－Ⅰ＞Ｘａｎ－Ⅲ＞Ｘａｎ－Ⅱ。结论穿心草口山酮具有一定的抗氧化作用，能直接清除活性氧自由基。

Effects of canscora lucidissima xanthones on antioxidation in vitro

AIM To study antioxidation of canscora luciadissima xanthone(Xan):1,8 dihydroxy,3,5 dimethoxyxanthone(Xan Ⅰ); and 1 hydroxy,5 dimethoxyxanthone(Xan Ⅱ);1 hydroxy,3,7,8 trithoxyxanthone(Xan Ⅲ) on homogenate and RBC autoxidation. METHODS Samples of tissues homogenates and RBC suspension were pretreated with Xans. The generation of malondialdehyde(MDA) was examined. The generation of O·2 produced by pyrogallol autoxidation and the ·OH produced by Cu2+ Vit C were examined by being pretreated with Xans. RESULTS ① The produc tion of lipid peroxides in normal brain, liver and heart homogenate of rat and elevation of produc tion of lipid peroxides induced by cysteine and FeSO4 in homogenate were inhibited by addtion of Xans. ② Xan inhibited that RBC hemolysis and the generation of MDA was decreased. ③ The O·2 produced by autoxidation of pyrogallol and the ·OH produced by Cu2+ Vit C system could be scavenged by Xans. ④ The potency of scavenging oxigen free radal is that Xan Ⅰ>Xan Ⅲ>Xan Ⅱ among the Xans. CONCLUSION Canscora lucidissima xanthones have the effect of antilipid peroxidation and may scavenge both O·2 and ·OH.