Assessment of coenzyme Q10 bioaccessibility and its dose-dependent protective effects on sperm motility, morphology and intracellular ROS levels

ABSTRACT Infertility is found in approximately 15% of couples all over the world and male factors alone are responsible for approximately 50% of infertility. The aim of this study was to investigate the effect of Coenzyme Q10 (CoQ10) supplementation on sperm mobility, morphology and reactive oxygen species (ROS) content and to assess its bioaccessibility in selected dietary sources relevant to human nutrition. The bioaccessibility of CoQ10 in several food samples was determined using high-performance liquid chromatography (HPLC). Based on these bioaccessible concentrations, the effects of CoQ10 (10, 50 and 100 µM) on sperm motility and morphology were evaluated in infertile patients. To evaluate the cellular response to CoQ10, MTT assay was employed for cytotoxicity assessment, while flow cytometry was utilized to quantify intracellular ROS production. In vitro gastrointestinal digestion analysis confirmed the high bioaccessibility of CoQ10, with the 50 µM concentration identified as the optimal dose for therapeutic application. This concentration exhibited superior biocompatibility in L929 cells, maintaining high cell viability without cytotoxic effects. Treatment with 50 µM CoQ10 significantly improved both total and progressive sperm motility compared to the control group. Moreover, the 50 µM CoQ10 significantly reduced intracellular ROS levels, which was associated with the preservation of sperm structural integrity by reducing acrosomal, nuclear and tail anomalies ( p < 0.05). Our results suggested that dietary intake and supplementation of CoQ10-enriched foods may exert beneficial therapeutic effects on low sperm motility. While CoQ10 significantly improves sperm motility at optimal concentrations (50 µM), high doses may exert cytotoxic effects on cells.