Healthy Literature
山桑子萃取物在光誘導視網膜病變老鼠模式的視神經保護功效
Neuroprotective effect of bilberry extract in a murine model of photo-stressed retina
/ 文獻筆記 /
過度暴露於光線之下，會促進退行性及致盲性的視網膜疾病，如退化性黃斑部病變和視網膜色素病變。然而，光誘導所造成的視網膜病變的潛在機制尚未完全了解，並且也尚未提出可被廣推的預防性方法。山桑子萃取物是一強效抗氧化劑的補充劑，可改善眼睛不適的症狀。在這項研究中，主要在研究山桑子萃取物對小鼠的視網膜受光誘導的神經保護作用。這項研究除了有助於了解光誘導的機制外，其研究結果顯示小鼠透過山桑子萃取物的攝取能減少光誘導所造成的視網膜過氧化物質濃度及內質網壓力，進而可減輕因光誘導所造成的細胞凋亡和視覺功能障礙問題。總結研究結果我們可知道，適當的攝取山桑子萃取物可有效預防光誘導視網膜病變。
Excessive exposure to light promotes degenerative and blinding retinal diseases such as age-related macular degeneration and retinitis pigmentosa. However, the underlying mechanisms of photo-induced retinal degeneration are not fully understood, and a generalizable preventive intervention has not been proposed. Bilberry extract is an antioxidant-rich supplement that ameliorates ocular symptoms. However, its effects on photo-stressed retinas have not been clarified. In this study, we examined the neuroprotective effects of bilberry extract against photo-stress in murine retinas. Light-induced visual function impairment recorded by scotopic and phototopic electroretinograms showing respective rod and cone photoreceptor function was attenuated by oral administration of bilberry extract through a stomach tube in Balb/c mice (750 mg/kg body weight). Bilberry extract also suppressed photo-induced apoptosis in the photoreceptor cell layer and shortening of the outer segments of rod and cone photoreceptors. Levels of photo-induced reactive oxygen species (ROS), oxidative and endoplasmic reticulum (ER) stress markers, as measured by real-time reverse transcriptase polymerase chain reaction, were reduced by bilberry extract treatment. Reduction of ROS by N-acetyl-L-cysteine, a well-known antioxidant also suppressed ER stress. Immunohistochemical analysis of activating transcription factor 4 expression showed the presence of ER stress in the retina, and at least in part, in Müller glial cells. The photo-induced disruption of tight junctions in the retinal pigment epithelium was also attenuated by bilberry extract, repressing an oxidative stress marker, although ER stress markers were not repressed. Our results suggest that bilberry extract attenuates photo-induced apoptosis and visual dysfunction most likely, and at least in part, through ROS reduction, and subsequent ER stress attenuation in the retina. This study can help understand the mechanisms of photo-stress and contribute to developing a new, potentially useful therapeutic approach using bilberry extract for preventing retinal photo-damage.—文獻摘要
Osada H1, Okamoto T1,2, Kawashima H1,2, Toda E1, Miyake S1,3, Nagai N1,2, Kobayashi S3, Tsubota K2, Ozawa Y1,2—文獻出處
https://www.ncbi.nlm.nih.gov/pubmed/28570634 文獻連結
