Zinkham W H, Oski F A
Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore 21205, USA.
Pediatrics. 1996 May;97(5):707-9.
To evaluate the in vitro oxidation potential of lawsone (2-hydroxy-1,4 naphthoquinone). Lawsone is a chemical present in henna, the crushed leaves of which are used worldwide as a cosmetic agent to stain the hair, skin, and nails.
Venous blood from glucose-6-phosphate dehydrogenase (G6PD)-normal and G6PD A- subjects were incubated with various amounts of lawsone for 2 hours at 37 degrees C. Reduced glutathione and methemoglobin (MHb) levels were measured before and after incubation.
Final molar concentrations of lawsone in normal blood of 1.4, 2.8, 5.7, and 8.6 x 10-3 mol/L increased MHb percentages from 0.5% to 2.2%, 8.3%, 9.5% and 12.5%, respectively. In a C6PD A- blood, MHb percentages were 19.8%, 32.2%, 44.9%, and 53.9%. At a lawsone concentration of 2.8 x 10-3 mol/L, blood from 15 healthy adults formed MHb percentages of 7.4% +/- 3.3% (+/- 1 SD); in blood from 4 G6PD A- adults, percentages were 44.5%, 40.6%, 41.3%, and 42.8%. Simultaneous measurements of reduced glutathione revealed preincubation values of greater than 40 mg/100 mL of red cells in blood of healthy and G6PD A- subjects. Postincubation values were greater than 40 in blood of healthy subjects and less than 40 in blood of G6PD A- subjects.
These in vitro observations indicate that lawsone is an agent capable of causing oxidative hemolysis. In regions of the world where there is a high incidence of G6PD deficiency and unexplained hyperbilirubinemia, oxidative hemolysis secondary to the cutaneous application of henna could be the initiating event.
评估指甲花醌（2-羟基-1,4-萘醌）的体外氧化潜力。指甲花醌是指甲花中含有的一种化学物质，其碾碎的叶子在世界各地被用作化妆品，用于染发、染皮肤和染指甲。
将葡萄糖-6-磷酸脱氢酶（G6PD）正常和G6PD A-受试者的静脉血与不同量的指甲花醌在37℃下孵育2小时。在孵育前后测量还原型谷胱甘肽和高铁血红蛋白（MHb）水平。
正常血液中指甲花醌的最终摩尔浓度分别为1.4、2.8、5.7和8.6×10-3mol/L时，高铁血红蛋白百分比分别从0.5%增加到2.2%、8.3%、9.5%和12.5%。在G6PD A-血液中，高铁血红蛋白百分比分别为19.8%、32.2%、44.9%和53.9%。在指甲花醌浓度为2.8×10-3mol/L时，15名健康成年人的血液中高铁血红蛋白百分比为7.4%±3.3%（±1标准差）；在4名G6PD A-成年人的血液中，百分比分别为44.5%、40.6%、41.3%和42.8%。同时测量还原型谷胱甘肽发现，健康受试者和G6PD A-受试者血液中红细胞的孵育前值大于40mg/100mL。健康受试者血液中的孵育后值大于40，而G6PD A-受试者血液中的孵育后值小于40。
这些体外观察结果表明，指甲花醌是一种能够引起氧化性溶血的物质。在世界上葡萄糖-6-磷酸脱氢酶缺乏症和不明原因高胆红素血症发病率较高的地区，皮肤涂抹指甲花引起的氧化性溶血可能是起始事件。
