Title : Antioxidant power: A unified defense against glaucoma and retinoblastoma
Abstract:
Purpose: This study investigated the effects of coenzyme Q10 (CoQ10) and Trolox on the N-methyl-D-aspartate (NMDA) induced death of retinal cells in glaucomatous conditions in vivo, and its effect on retinoblastoma in vitro and in ovo.
Methods: Wistar rats for in vivo and Y79 retinoblastoma cells were used for in vitro experiments. Drug interactions were assessed on normal human retinal pigment epithelial cells(ARPE-19). Cell culture assays like cytotoxicity assays (MTT/CCK-8), scratch/wound healing, and colony formation assays along with mitochondrial membrane potential (MMP), reactive oxygen species (ROS) levels, and apoptotic changes were analyzed. mRNA and protein levels of VEGF, ERK, and Akt were estimated using RT-PCR and western blotting respectively. Neuroprotection in rat retina was evaluated histopathologically and ultrastructurally. ROS, MMP, and mRNA levels of NMDA and VEGF receptors along with VEGF protein levels were investigated.
Results: The action of CoQ10 and Trolox was synergistic in reducing Y79 cell cytotoxicity, migration and colony-forming abilities at 30 µM each without affecting ARPE-19 cells. Results from co-culture of Y79 cells with human vein endothelial cells (HUVECs) and chick chorioallantoic membrane assay demonstrated a potential anti-angiogenic effect. Increased ROS and reduced MMP were noted, with G2/M phase cell cycle arrest and cell death mediated by the ERK/Akt pathway.
In vivo CoQ10 and Trolox improved retinal morphology, reduced ROS and nitrite and rejuvenated MMP. Depreciated Grin2B, increased VEGF and upregulated neuroprotective markers NMDAR2A and VEGFR2 suggested that CoQ10 alone and CoQ10 with Trolox showed enhanced neuroprotective effects compared to individually.
Conclusion: Hence, this is the first study in our knowledge, that confirms that CoQ10 alone and/or combined with trolox has a stronger anti-tumor effect against advanced Rb in humans both in vitro and in ovo while also demonstrating how both could bring down upregulated VEGF levels and how these two antioxidants could combat RGC death in excitotoxic conditions.
