cyanidin-3-o-beta-glucopyranoside and Retinal-Degeneration

Cyanidin-3-glucoside (C3G) is a major anthocyanin in berries and a potential nutritional supplement for preventing retinal degeneration. However, the protective mechanism of C3G and its metabolites, protocatechuic acid (PCA) and ferulic acid (FA), remain unclear. The molecular mechanisms of C3G and its metabolites against retinal photooxidative damage in vivo are investigated.. Pigmented rabbits were orally administered C3G, PCA, and FA (0.11 mmol/kg/day) for 3 weeks. Electroretinography, histological analysis, and TUNEL assay showed that C3G and its metabolites attenuated retinal cell apoptosis. The expression of oxidative stress markers were upregulated after light exposure but attenuated by C3G and FA, which may be attributed to the elevated secretion and expression of heme oxygenase (HO-1) and nuclear factor erythroid-2 related factor 2 (Nrf2). C3G, PCA, and FA attenuated the secretion or expression of inflammation-related genes; FA suppressed nuclear factor kappa B (NF-κB) activation. The treatments attenuated the light-induced changes on certain apoptotic proteins and angiogenesis-related cytokines.. C3G and FA reduced light-induced retinal oxidative stress by activating the Nrf2/HO-1 antioxidant pathway. FA attenuated the light-induced retinal inflammation by suppressing NF-κB activation. C3G and its metabolites attenuated the photooxidation-induced apoptosis and angiogenesis in the retina.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehydes; Animals; Anthocyanins; Antioxidants; Apoptosis; Coumaric Acids; Cytokines; Deoxyguanosine; Glucosides; Heme Oxygenase-1; Hydroxybenzoates; In Situ Nick-End Labeling; Light; NF-E2-Related Factor 2; NF-kappa B; Oxidative Stress; Rabbits; Retina; Retinal Degeneration; Signal Transduction; Tyrosine; Up-Regulation

To investigate the effect of cyanidin-3-O-glucoside (C3G) on a rat retinal degeneration (RD) model.. Experimental RD was induced in rats by the intraperitoneal injection of N-methyl-N-nitrosourea (MNU) at 50 mg/kg. C3G extracted from mulberry (Morus alba L.) fruit (50 mg/kg) was orally administered, daily for 1, 2 and 4 weeks after MNU injection. The effects of C3G administration on MNU-induced RD retinas were histologically and functionally assessed by hematoxylin and eosin staining and electroretinography (ERG), respectively. The degree of retinal injury in C3G-administered RD rats was evaluated by immunohistochemistry with an antibody against glial fibrillary acidic protein (GFAP). The preferential protective effect of C3G on scotopic vision was examined by western blot analysis.. Marked loss of photoreceptors in the outer nuclear layer (ONL) was observed in RD rats at 2 and 4 weeks after MNU injection, while the ONL in the MNU-induced RD rats given C3G was relatively well preserved. Immunohistochemistry with anti-GFAP showed that retinal injury was also reduced in the retinas of the rats given C3G. Functional assessment by using ERG recordings showed that scotopic ERG responses were significantly increased in RD rats given C3G for 4 weeks (p < 0.01) compared with that of untreated RD rats. In the RD rats given short-term C3G (for 1 and 2 weeks), the increase in ERG responses was not significant. In addition, western blot analysis showed that rhodopsin level in the C3G-administered RD retinas significantly increased compared to that in the non-administered RD retinas (p < 0.05), whereas red/green opsin level did not show any significant difference.. Long-term administration of C3G extracted from mulberry fruit could structurally reduce photoreceptor damage and functionally improve scotopic visual functions in the RD rat model induced by MNU.

Topics: Alkylating Agents; Animals; Anthocyanins; Apoptosis; Disease Models, Animal; Electroretinography; Glucosides; Male; Methylnitrosourea; Morus; Night Vision; Photoreceptor Cells, Vertebrate; Plant Extracts; Rats; Rats, Sprague-Dawley; Retinal Degeneration