Determination of coenzyme Q10 level in human retina by the high-performance liquid chromatography

Background Researches have demonstrated that age-related macular degeneration (AMD) is associated with the oxidative stress injury of retina.Coenzyme Q10 (CoQ10) is an important antioxidant agent.CoQ10 level in blood plasma is a primary index of reflecting the oxidative stress ability of human.However,the study on CoQ10 content in retina has not been seen yet.ObjectiveThe aim of this study is to establish a method of detecting CoQ10 content in retina by the high-performance liquid chromatography (HPLC). Methods The retinas were isolated from 10 healthy eyes of donors aged 20-28 years.The donor eyes were obtained from National Development and Research Institute,Inc.USA.Isolated retina tissue was prepared into homogenate then lyophilized and deproteinized with methanol.Samples were extracted with heptane prior to the HPLC analysis with the chromatographic conditions as follows:RP-18 column,a mobile phase consisted of methanol-hexane-acetic acid-isopropanol (V/V=55:9:1:1) and 0.42% sodium acetate,ultraviolet rays (UV) detector at 275 nm.Results CoQ10 was effectively isolated from human retina.The limit of detection of CoQ10 was 0.14mg/L.The peak area and concentration of CoQ10 showed a good linear correlation within the concentration range of 0.2-395.00mg/L (R~2＝0.9943).Repeatability study showed that the relative standard deviations for CoQ10 at the concentration of 0.86mg/L,2.59mg/L and 3.45mg/L were 2.7%,0.1% and 3.3%,respectively.The within- and inter-day standard deviations for the analysis of CoQ10 were 1.6% and 3.7%,respectively.The recovery was 101%-113% for the human retina samples.The concentration of CoQ10 in 10 retinas from human donors was 0.51±0.20μg/eye in average.Conclusion A HPLC method for the quantified analysis of CoQ10 in human retina is developed. Key words: high-performance liquid chromatography; coenzyme Q10; retina; oxidative stress