scholarly journals Protective effects of quercetin in a rodent model of anterior ischemic optic neuropathy (rAION)

2019 ◽  
Author(s):  
Ya-nan Lyu ◽  
Jing-yu Min ◽  
Yuanyuan Gong ◽  
qing Gu ◽  
fang Wei

Abstract Background: Anterior ischemic optic neuropathy (AION) is the leading cause of sudden optic nerve-related (ON-related) vision loss in elderly people. However, no considerable treatments are available for the neuroprotection of NAION. The purpose of this study was to detect the effects of intravitreal injection of quercetin (Qcn) in a rodent model of anterior ischemic optic neuropathy (rAION). Methods: The rAION model was established using verteporfin and laser in a photodynamic procedure on the optic discs (ON) of rats. The rats received intravitreal injection of Qcn 2 days before the injury and once/week for 4 weeks after the infarct on optic neuropathy. Flash-visual evoked potential (VEP) were recorded to assess the visual function. TUNEL and retrograde Fluorogold labeling assessed the apoptosis and density of retinal ganglion cells (RGCs). ED-1 and Iba-1 staining of the optic nerves displayed the inflammatory response. Results: At 14 days post-infarct, Qcn treatment significantly reduced the number of apoptotic RGCs, as well as, ED1/Iba-1-positive cells/high power field(HPF) in the ON (p<0.01) as compared to the rAION group. At week 4 after rAION, 28.4% VEP amplitudes were estimated in the treated eyes of the fellow eyes in the rAION group and 64.7% in the rAION+Qcn group (p<0.01). In addition, Qcn saved the RGCs in the central retinas as compared to those of the rAION group (1967.5±162.1 and 2868±325.3 mm2, respectively (p<0.01), and the corresponding densities were 1654.8±104.8 and 2208±272.9 mm2 in the mid-peripheral retinas, respectively (p<0.01). Conclusion: The intravitreal injection of Qcn could protect the RGCs from injury in the rAION animal model, as demonstrated anatomically by RGC density and functionally by F-VEP. Moreover, Qcn might exert an anti-apoptosis role in the survival of RGCs and anti-inflammatory in the optic nerves.

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Zuohuizi Yi ◽  
Liao Chen ◽  
Xiaoling Wang ◽  
Changzheng Chen ◽  
Yiqiao Xing

Purpose. We sought to explore the effects of intravitreal injection of the Rho-kinase inhibitor Y-27632 in a rodent model of nonarteritic anterior ischemic optic neuropathy (rAION). Methods. The rAION model was established by using laser-induced photoactivation of intravenously administered Rose Bengal in rats. The rats received intravitreal injections of Y-27632 or PBS 1, 3, and 6 days after rAION induction. Optical coherence tomography (OCT) was performed at 2 days and 4 weeks after induction. Visual evoked potential (VEP) was used to evaluate the visual function at 4 weeks. Brn3a immunofluorescence staining of surviving RGCs and apoptosis assays of RGCs were performed at 4 weeks. Results. Optic nerve head (ONH) width was significantly reduced in the Y-27632 group compared with that in the PBS group at 2 days after induction (p<0.05). At 4 weeks, the P1 amplitude of flash-VEP (FVEP) in the Y-27632 group was significantly higher than that of the PBS group (p<0.05). The RGC densities in the central and midperipheral retinas in the Y-27632 group were significantly higher than those in the PBS group (p<0.05). Furthermore, there was a significant decrease in apoptotic RGCs in the Y-27632 group than in the PBS group (p<0.05). Conclusions. Intravitreal injection of Y-27632 had neuroprotective effects on ONH edema, RGC survival, and visual function preservation in rAION.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 902
Author(s):  
Jia-Ying Chien ◽  
Shu-Fang Lin ◽  
Yu-Yau Chou ◽  
Chi-Ying F. Huang ◽  
Shun-Ping Huang

Nonarteritic anterior ischemic optic neuropathy (NAION) is the most common cause of acute vision loss in older people, and there is no effective therapy. The effect of the systemic or local application of steroids for NAION patients remains controversial. Oroxylin A (OA) (5,7-dihydroxy-6-methoxyflavone) is a bioactive flavonoid extracted from Scutellariae baicalensis Georgi. with various beneficial effects, including anti-inflammatory and neuroprotective effects. A previous study showed that OA promotes retinal ganglion cell (RGC) survival after optic nerve (ON) crush injury. The purpose of this research was to further explore the potential actions of OA in ischemic injury in an experimental anterior ischemic optic neuropathy (rAION) rat model induced by photothrombosis. Our results show that OA efficiently attenuated ischemic injury in rats by reducing optic disc edema, the apoptotic death of retinal ganglion cells, and the infiltration of inflammatory cells. Moreover, OA significantly ameliorated the pathologic changes of demyelination, modulated microglial polarization, and preserved visual function after rAION induction. OA activated nuclear factor E2 related factor (Nrf2) signaling and its downstream antioxidant enzymes NAD(P)H:quinone oxidoreductase (NQO-1) and heme oxygenase 1 (HO-1) in the retina. We demonstrated that OA activates Nrf2 signaling, protecting retinal ganglion cells from ischemic injury, in the rAION model and could potentially be used as a therapeutic approach in ischemic optic neuropathy.


Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1538
Author(s):  
Berta Sanz-Morello ◽  
Hamid Ahmadi ◽  
Rupali Vohra ◽  
Sarkis Saruhanian ◽  
Kristine Karla Freude ◽  
...  

Increasing evidence indicates that changes in the redox system may contribute to the pathogenesis of multiple optic neuropathies. Optic neuropathies are characterized by the neurodegeneration of the inner-most retinal neurons, the retinal ganglion cells (RGCs), and their axons, which form the optic nerve. Often, optic neuropathies are asymptomatic until advanced stages, when visual impairment or blindness is unavoidable despite existing treatments. In this review, we describe systemic and, whenever possible, ocular redox dysregulations observed in patients with glaucoma, ischemic optic neuropathy, optic neuritis, hereditary optic neuropathies (i.e., Leber’s hereditary optic neuropathy and autosomal dominant optic atrophy), nutritional and toxic optic neuropathies, and optic disc drusen. We discuss aspects related to anti/oxidative stress biomarkers that need further investigation and features related to study design that should be optimized to generate more valuable and comparable results. Understanding the role of oxidative stress in optic neuropathies can serve to develop therapeutic strategies directed at the redox system to arrest the neurodegenerative processes in the retina and RGCs and ultimately prevent vision loss.


2013 ◽  
Vol 54 (13) ◽  
pp. 7952 ◽  
Author(s):  
Bernard J. Slater ◽  
Fernandino L. Vilson ◽  
Yan Guo ◽  
Daniel Weinreich ◽  
Shelly Hwang ◽  
...  

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