The advantages of a novel CoQ10 delivery system in skin photo-protection

Skin photo-ageing induced by ultraviolet (UV) radiation is mainly ascribed to oxidative stress and reactive oxygen species (ROS). Coenzyme Q10 (CoQ10) has been reported as a powerful antioxidant in plasma. However, CoQ10 was barely satisfactory in topical drug delivery because of its lipid solubility. To improve the anti-oxidative efficiency of CoQ10 in skin photo-ageing, the present research prepared a novel CoQ10 nano-structured lipid carrier (CoQ10-NLC) and characterised it by size and freeze-fracture transmission electron microscopy (FF-TEM). In UVA-irradiated fibroblasts, the protection of CoQ10-NLC was more effective than the CoQ10-emulsion as demonstrated by cell viability and morphological changes of the cell body and nucleus. In addition, malondialdehyde (MDA, the product of lipid peroxidation) concentration decreased by 61.5% in the group treated with CoQ10-NLC compared to the group subjected to general CoQ10-emulsion. In the presence of CoQ10-NLC, the activities of the anti-oxidative enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) were reinstated to 81% and 75%, respectively, of the control group. In vivo, the CoQ10-NLC displayed a stronger capability to penetrate the stratum corneum and permeate the dermis after a topical skin application. These results reveal that CoQ10-NLC has greater antioxidant properties and topical skin penetration than the CoQ10-emulsion.