Coenzyme Q10 protects retinal cells against oxidative stress in vitro and in vivo

Purpose:To investigate the neuroprotective effects of coenzyme Q10 and/or a vitamin E analogue on retinal damage both in vitro and in vivo.Methods:We employed cultured retinal ganglion cells (RGC-5, a rat ganglion cell-line transformed using E1A virus) in vitro. Cell damage was induced by 24-h hydrogen peroxide (H2O2) exposure, and cell viability was measured using tetrazolium salt (WST-8). To examine the retinal damage induced by intravitreal N-methyl-d-aspartate (NMDA) injection in mice in vivo, coenzyme Q10 at 10 mg/kg with or without α-tocopherol at 10 mg/kg was administered orally (p.o.) each day for 14days, with NMDA being intravitreally injected on day 7 of this course.Results:In RGC-5, a combination of coenzyme Q10 and trolox, a water-soluble vitamin E analogue (a derivative of α-tocopherol), prevented cell damage more effectively than either agent alone. Coenzyme Q10 and α-tocopherol (separately or together) reduced the retinal damage, number of TUNEL-positive cells in the ganglion cell layer (GCL), and 4-hydroxyl-2-nonenal (4-HNE) expression induced by NMDA in mice in vivo.Conclusions:Coenzyme Q10 and/or these vitamin E analogues exert neuroprotective effects against retinal damage both in vitro and in vivo.