Di Yang1,2, Kwok-Fai So2,3, Amy Cy Lo2,3. 1. Department of Ophthalmology, First Affiliated Hospital of Kunming Medical University, Kunming Medical University, Kunming, Yunnan, China. 2. Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong. 3. Research Center of Heart, Brain, Hormone and Healthy Aging, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong.
Abstract
BACKGROUND: Retinal ischaemia is a common feature shared by numerous eye diseases. Ischaemic insult leads to retinal dysfunction and neuronal death. Lycium barbarum polysaccharides are well known for eyesight preservation. We have previously reported the effect of Lycium barbarum polysaccharides on cell death, blood ocular barrier and oxidative stress within 24 h retinal ischaemia. This study focuses on retinal function and looks for ultrastructural and cellular correlates after a relatively long period of reperfusion for 7 days. METHODS: Two-hour ischaemia was induced by intraluminal occlusion of the internal carotid artery. Either Lycium barbarum polysaccharides or phosphate-buffered saline was orally pre-administered daily for 7 days before ischaemia and continued for 1, 3 and 7 days after reperfusion. Electroretinogram was performed to evaluate visual function. Paraffin-embedded retinal sections were prepared 7 days after reperfusion and utilized for histological and immunohistochemical analyses. RESULTS: Ischaemia led to sustained inhibition of b-wave amplitude and oscillatory potentials. Lycium barbarum polysaccharide-treated mice exhibited greater b-wave and oscillatory potential responses from days 1 to 7 after reperfusion. In addition, increased number of viable cells and calretinin-positive cells, as well as enhanced immunoreactivity of protein kinase C alpha and attenuated glial fibrillary acidic protein expression, was noted in Lycium barbarum polysaccharide-treated retina. CONCLUSIONS: Daily consumption of Lycium barbarum polysaccharides effectively alleviated ischaemia-induced retinal dysfunction as well as reduced correlated neuronal death and glial activation. This prolonged effect could last at least 7 days. It suggested that Lycium barbarum polysaccharides might serve as a neuroprotective agent in ischaemic retinopathies.
BACKGROUND:Retinal ischaemia is a common feature shared by numerous eye diseases. Ischaemic insult leads to retinal dysfunction and neuronal death. Lycium barbarum polysaccharides are well known for eyesight preservation. We have previously reported the effect of Lycium barbarum polysaccharides on cell death, blood ocular barrier and oxidative stress within 24 h retinal ischaemia. This study focuses on retinal function and looks for ultrastructural and cellular correlates after a relatively long period of reperfusion for 7 days. METHODS: Two-hour ischaemia was induced by intraluminal occlusion of the internal carotid artery. Either Lycium barbarum polysaccharides or phosphate-buffered saline was orally pre-administered daily for 7 days before ischaemia and continued for 1, 3 and 7 days after reperfusion. Electroretinogram was performed to evaluate visual function. Paraffin-embedded retinal sections were prepared 7 days after reperfusion and utilized for histological and immunohistochemical analyses. RESULTS:Ischaemia led to sustained inhibition of b-wave amplitude and oscillatory potentials. Lycium barbarum polysaccharide-treated mice exhibited greater b-wave and oscillatory potential responses from days 1 to 7 after reperfusion. In addition, increased number of viable cells and calretinin-positive cells, as well as enhanced immunoreactivity of protein kinase C alpha and attenuated glial fibrillary acidic protein expression, was noted in Lycium barbarum polysaccharide-treated retina. CONCLUSIONS: Daily consumption of Lycium barbarum polysaccharides effectively alleviated ischaemia-induced retinal dysfunction as well as reduced correlated neuronal death and glial activation. This prolonged effect could last at least 7 days. It suggested that Lycium barbarum polysaccharides might serve as a neuroprotective agent in ischaemic retinopathies.
Authors: Sum Sum Kwok; Yashan Bu; Amy Cheuk-Yin Lo; Tommy Chung-Yan Chan; Kwok Fai So; Jimmy Shiu-Ming Lai; Kendrick Co Shih Journal: Biomed Res Int Date: 2019-02-12 Impact factor: 3.411