title: Crocin protects retinal ganglion cells against H2O2-induced damage through the mitochondrial pathway and activation of NF-κB.
abstract: Glaucoma is a degenerative nerve disorder that results in irreversible blindness. It has been reported that the apoptosis of retinal ganglion cells (RGCs) is a hallmark of glaucoma. Oxidative stress is one of the major factors that cause apoptosis of RGCs. Crocin has many beneficial effects, including antioxidant and anti-apoptotic actions. However, the mechanism by which crocin protects against oxidative stress‑induced damage to RGCs remains unclear. The present study aimed to investigate the mechanism by which crocin protects RGC-5 cells against H2O2-induced damage. H2O2 was used to establish a model of oxidative stress injury in RGC-5 cells to mimic the development of glaucoma in vitro. Different concentrations (0.1 and 1 µM) of crocin were added to test whether crocin was capable of protecting RGCs from H2O2-induced damage. WST-1, lactic dehydrogenase (LDH) release and Annexin V/FITC assays were then performed. Levels of reactive oxygen species (ROS) were detected using a ROS assay kit, mitochondrial membrane potential (ΔΨm) was analyzed by JC-1 staining, caspase-3 activity was examined using a Caspase-3 assay kit, and the protein levels of Bax, Bcl-1 and cytochrome c were measured using western blot analysis. In addition, the protein level of phosphorylated nuclear factor-κB (p-NF-κB) p65 was also evaluated using western blot analysis. The results showed that crocin protected RGC-5 cells from apoptosis, decreased LDH release and enhanced cell viability. Additional experiments demonstrated that crocin decreased ROS levels, increased ΔΨm, downregulated the protein expression of Bax and cytochrome c, promoted Bcl-2 protein expression and activated NF-κB. Taken together, the findings of this study indicate that crocin prevented H2O2‑induced damage to RGCs through the mitochondrial pathway and activation of NF-κB.
authors.affiliation: Shaanxi Ophthalmic Medical Center, Xi'an No. 4 Hospital, Affiliated Guangren Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China.
authors.forename: Bochang
authors.initials: B
authors.lastname: Lv
authors.affiliation: Department of Anatomy, Histology and Embryology, K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China.
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
authors.affiliation: Shaanxi Ophthalmic Medical Center, Xi'an No. 4 Hospital, Affiliated Guangren Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China.
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Department of Physiology and Pathophysiology, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Fuquan
authors.initials: F
authors.lastname: Huo
authors.affiliation: Department of Anatomy, Histology and Embryology, K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Shaanxi Ophthalmic Medical Center, Xi'an No. 4 Hospital, Affiliated Guangren Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China.
authors.forename: Xinguang
authors.initials: X
authors.lastname: Yang
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002338:Carotenoids / Q000494:pharmacology*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D005901:Glaucoma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D016328:NF-kappa B / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects*; D010766:Phosphorylation / Q000187:drug effects; D020011:Protective Agents / Q000494:pharmacology*; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D012165:Retinal Ganglion Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000975:Antioxidants; D016328:NF-kappa B; D020011:Protective Agents; D017382:Reactive Oxygen Species; D002338:Carotenoids; C029036:crocin; D006861:Hydrogen Peroxide