Coenzyme Q10 Treatment Monitoring in Different Human Biological Samples

Abstract

Coenzyme Q10 (CoQ) treatment monitoring is a matter of debate since CoQ distribution from plasma to blood cells and tissues is not fully understood. We aimed to analyze the CoQ levels in a wide set of human biological samples (plasma, blood mononuclear cells (BMCs), platelets, urinary cells, and skeletal muscle) from a group of 11 healthy male runners before and after CoQ supplementation. The CoQ content in the different samples was analyzed by HPLC coupled to electrochemical detection. No significant differences were observed in the CoQ levels measured in the BMCs, platelets, and urine after the one-month treatment period. Plasma CoQ (expressed in absolute values and values relative to total cholesterol) significantly increased after CoQ supplementation (p = 0.003 in both cases), and the increase in CoQ in muscle approached significance (p = 0.074). CoQ levels were increased in the plasma of all supplemented subjects, and muscle CoQ levels were increased in 8 out of 10 supplemented subjects. In conclusion, the analysis of CoQ in plasma samples seems to be the best surrogate biomarker for CoQ treatment monitoring. Moreover, oral CoQ administration was effective for increasing muscle CoQ concentrations in most subjects.

Technical Aspects of Coenzyme Q10 Analysis: Validation of a New HPLC-ED Method

“…Passing-Bablok regression showed no differences between the two methods: the intercept and slope with their 95% confidence intervals were −0.01(−0.02-0) and 1.03(1-1.06), respectively; the cumulative sum linearity test p value was 0.3, which indicates no significant deviation from linearity (Figure S4). Therefore, the data obtained with this new procedure were consistent with the previous procedure, and we maintained our reference values [20,24], which were similar to those reported in the literature by other groups [25][26][27].…”

“…The measurement of CoQ in lymphocytes can also be useful for diagnosis if the patient has not received CoQ supplementation [29]. Regarding CoQ treatment monitoring, we previously reported that among a wide array of biological samples, plasma appeared to be the best specimen for this purpose, since the CoQ determination in cells (such as BMCs, platelets and urinary cells) requires extensive preanalytical preparation and may display high biological variation [24].…”

“…Our group reported a procedure for CoQ determination in serum by HPLC-ED almost two decades ago [30]. Since then, we reported CoQ determination in other biological specimens, including muscle, fibroblasts, urine, platelets and BMCs [19,20,24]. All of these procedures were based on the use of the ESA Coulochem II ED.…”

Cellular Models for Primary CoQ Deficiency Pathogenesis Study

“…The plasma amounts of CoQ do not represent the levels in other cells and tissues [ 15 ]. However, the increase in CoQ content in plasma after ubiquinol supplementation is linked to an increased tendency of CoQ levels in the skeletal muscle of healthy people [ 19 ]. CoQ has also been determined in platelets and blood mononuclear cells [ 15 , 19 , 20 ], but there is not enough evidence that the levels in these cells could reflect the content in other tissues [ 21 ].…”

“…However, the increase in CoQ content in plasma after ubiquinol supplementation is linked to an increased tendency of CoQ levels in the skeletal muscle of healthy people [ 19 ]. CoQ has also been determined in platelets and blood mononuclear cells [ 15 , 19 , 20 ], but there is not enough evidence that the levels in these cells could reflect the content in other tissues [ 21 ]. A more reliable analysis of the primary deficiency of CoQ has been done using skeletal muscle biopsies.…”