CoQ 10 Phytosomes Improve Cellular Ubiquinone Uptake in Skeletal Muscle Cells: An Ex Vivo Study Using CoQ 10 -Enriched Low-Density Lipoproteins Obtained in a Randomized Crossover Study.

Coenzyme Q 10 (CoQ 10 ) bioavailability in vivo is limited due to its lipophilic nature. Moreover, a large body of evidence in the literature shows that muscle CoQ 10 uptake is limited. In order to address cell specific differences in CoQ uptake, we compared cellular CoQ 10 content in cultured human dermal fibroblasts and murine skeletal muscle cells that were incubated with lipoproteins from healthy volunteers and enriched with different formulations of CoQ 10 following oral supplementation. Using a crossover design, eight volunteers were randomized to supplement 100 mg/daily CoQ 10 for two weeks, delivered both in phytosome form (UBQ) as a lecithin formulation and in CoQ 10 crystalline form. After supplementation, plasma was collected for CoQ 10 determination. In the same samples, low density lipoproteins (LDL) were extracted and normalized for CoQ 10 content, and 0.5 µg/mL in the medium were incubated with the two cell lines for 24 h. The results show that while both formulations were substantially equivalent in terms of plasma bioavailability in vivo, UBQ-enriched lipoproteins showed a higher bioavailability compared with crystalline CoQ 10 -enriched ones both in human dermal fibroblasts (+103%) and in murine skeletal myoblasts (+48%). Our data suggest that phytosome carriers might provide a specific advantage in delivering CoQ 10 to skin and muscle tissues.