In Vitro Antioxidant Effects of Coenzyme Q10 on Cellular Metabolism in Aged Mesenchymal Stem Cells

(1) Background: this study investigates the short-term effects of coenzyme Q10 (CoQ10) on mitochondrial respiration, fatty acid metabolism, oxidative stress gene expression, and sirtuin activity in young (passage 5, P5) and aged (passage 16, P16) mesenchymal stem cells (MSCs). (2) Methods: Mitochondrial respiration was assessed by measuring oxygen consumption after 24 h of treatment. Gas chromatography–mass spectrometry (GC-MS) analysis assessed cellular fatty acid methyl ester profiles. Quantitative polymerase chain reaction (qPCR) demonstrated the passage-dependent expression of oxidative stress-related genes and sirtuins in response to CoQ10 treatment. (3) Results: CoQ10 enhanced basal respiration and spare respiratory capacity (SRC), particularly in older senescent cells. CoQ10 improved basal respiration and ATP-linked oxygen consumption in young MSCs and partially restored these functions in aged MSCs. Moreover, CoQ10 increased saturated fatty acids, particularly in young cells, and decreased monounsaturated fatty acids in aged cells. qPCR analysis revealed passage-dependent modifications in oxidative stress-related genes and sirtuin expression; CoQ10 exposure significantly influenced SIRT1 and SIRT3 activity, leading to an increase in PPARγ and CAT expression. (4) Conclusions: these results highlight CoQ10’s potential to alleviate mitochondrial dysfunction and metabolic shifts associated with cellular aging, underscoring its therapeutic value for age-related mitochondrial and metabolic disorders.