Sechovcová Soňa, Královcová Pavla, Kanďár Roman, Ventura Karel
Department of Biological and Biochemical Sciences, University of Pardubice, Czech Republic.
Department of Analytical chemistry, University of Pardubice, Czech Republic.
Biomed Chromatogr. 2018 May;32(5):e4172. doi: 10.1002/bmc.4172. Epub 2018 Jan 10.
Lipoic acid (LA) is used extensively as a therapeutic agent for the treatment of various diseases. Many methods have been reported for the determination of LA plasma levels and its metabolites after its supplementation, but available information concerning endogenous plasma levels is still scarce. Studies which directly focused on determining the endogenous plasma levels provided highly controversial results, <4.9 nmol/L or 143.7-197.0 nmol/L. The main aim of this study was to verify the levels of free LA in the plasma of 40 individuals (17 women, 23 men). This group was nonsupplemented with LA and met the conditions for incorporation into the blood donors register. We measured the levels of LA using an HPLC method with very sensitive coulometric detection after previous sample preparation including deproteination and solid-phase extraction with a Phenyl cartridge. Our limit of detection was 1.85 nmol/L and was better than the values reported in studies that directly focused on determining the endogenous plasma levels of LA: 2.4 and 4.9 nmol/L respectively. However, the levels of free LA in the plasma of nonsupplemented voluntary blood donors were not detectable in all cases. The presented results of our study show that endogenous concentrations of LA are <1.85 nmol/L.
硫辛酸（LA）被广泛用作治疗各种疾病的治疗剂。已经报道了许多测定LA补充后血浆水平及其代谢物的方法，但关于内源性血浆水平的现有信息仍然很少。直接专注于测定内源性血浆水平的研究得出了极具争议的结果，即<4.9 nmol/L或143.7 - 197.0 nmol/L。本研究的主要目的是验证40名个体（17名女性，23名男性）血浆中游离LA的水平。该组未补充LA且符合纳入献血者登记册的条件。在先前包括脱蛋白和用苯基柱进行固相萃取的样品制备后，我们使用具有非常灵敏的库仑检测的HPLC方法测量了LA的水平。我们的检测限为1.85 nmol/L，优于直接专注于测定LA内源性血浆水平的研究报告的值：分别为2.4和4.9 nmol/L。然而，在所有情况下，未补充LA的自愿献血者血浆中的游离LA水平均未检测到。我们研究的呈现结果表明，LA内源性浓度<1.85 nmol/L。
