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[摘要]
本文采用分光光度法测定姜黄素对ABTS和DPPH自由基的清除能力;运用AAPH诱导红细胞氧化性溶血考察姜黄素对AAPH诱导人血红细胞损伤的抑制作用。通过MTT方法考察姜黄素对A375恶性黑色素瘤生长状态的影响,并用流式细胞仪检测细胞凋亡数量;运用Western blot测定姜黄素对JNK和Akt蛋白表达的影响。结果表明,姜黄素对DPPH和ABTS自由基具有较好的清除能力,呈浓度和时间依赖性;同时,姜黄素能有效抑制AAPH诱导红细胞溶血,当姜黄素为40 μM时,溶血抑制率达到52.78±1.03%。MTT结果表明,随着姜黄素浓度的升高,A375细胞存活率逐渐下降,当姜黄素为40 μM,A375的细胞存活率仅为21.50±1.60%。流式分析发现,随着姜黄素浓度的提高,细胞凋亡峰(SubG1)的含量逐渐增加。当姜黄素为40 μM时,细胞内SubG1峰的含量达到了63.30%。进一步Western blot分析发现姜黄素诱导A375细胞凋亡与上调JNK磷酸化的水平和下调AKt磷酸化的水平有关。
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[Abstract]
In this paper, spectrophotometric method was employed to determine the ability of curcumin to scavenge 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, and the oxidative hemolysis of erythrocytes induced by 2, 2′-azobis (2-amidinopropane) dihydrochloride (AAPH) was used to investigate the inhibitory effect of curcumin on AAPH-induced damage to human erythrocytes. The effect of curcumin on the viability of A375 malignant melanoma cells was measured by MTT assay, and the population of the apoptotic cells was detected by a flow cytometer. The effect of curcumin on the expression levels phosphorylated JNK and Akt was analyzed via Western blot assay. These results showed that curcumin exhibited strong scavenging effects on ABTS and DPPH free radicals in a dose- and time-dependent manner. Meanwhile, curcumin also effectively inhibited the AAPH-induced hemolysis of erythrocytes. The hemolysis inhibition rate of curcumin increased to 52.78 ± 1.03% at a concentration of 40 μM. The MTT assay showed that an increasing concentration of curcumin decreased the viability of A375 cells gradually. The cell viability after treatment with curcumin (40 μM) was only 21.50 ± 1.60%. Further flow cytometric studies showed that the SubG1 peak (apoptotic cells) increased in response to increasing curcumin concentrations. The SubG1 peak (apoptotic cells) reached 63.30% when the curcumin concentration was 40 μM. Further studies by Western blot assay demonstrated that the curcumin-induced apoptosis in A375 cells was related to upregulation of JNK phosphorylation and downregulation of Akt phosphorylation.
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[基金项目]
高等学校博士点基金新教师项目(20110172120033),国家自然科学基金青年基金项目(31101278),广东省产学研结合项目(2012B091100075),“扬帆计划”引进创新创业团队专项资助(201312 H05),华南理工大学中央高校基本科研业务费(2013ZZ0069)资助