A Water Soluble CoQ10 Formulation Improves Intracellular Distribution and Promotes Mitochondrial Respiration in Cultured Cells

Background: Mitochondria are both the cellular powerhouse and the major source of reactive oxygen species. Coenzyme Q(10) plays a key role in mitochondrial energy production and is recognized as a powerful antioxidant. For these reasons it can be argued that higher mitochondrial ubiquinone levels may enhance the energy state and protect from oxidative stress. Despite the large number of clinical studies on the effect of CoQ(10) supplementation, there are very few experimental data about the mitochondrial ubiquinone content and the cellular bioenergetic state after supplementation. Controversial clinical and in vitro results are mainly due to the high hydrophobicity of this compound, which reduces its bioavailability. Principal Findings: We measured the cellular and mitochondrial ubiquinone content in two cell lines (T67 and H9c2) after supplementation with a hydrophilic CoQ(10) formulation (Qter (R)) and native CoQ(10). Our results show that the water soluble formulation is more efficient in increasing ubiquinone levels. We have evaluated the bioenergetics effect of ubiquinone treatment, demonstrating that intracellular CoQ(10) content after Qter supplementation positively correlates with an improved mitochondrial functionality (increased oxygen consumption rate, transmembrane potential, ATP synthesis) and resistance to oxidative stress. Conclusions: The improved cellular energy metabolism related to increased CoQ(10) content represents a strong rationale for the clinical use of coenzyme Q(10) and highlights the biological effects of Qter (R), that make it the eligible CoQ(10) formulation for the ubiquinone supplementation.