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.