title: Cyanidin-3-glucoside extracted from mulberry fruit can reduce N-methyl-N-nitrosourea-induced retinal degeneration in rats.
abstract: OBJECTIVE
  To investigate the effect of cyanidin-3-O-glucoside (C3G) on a rat retinal degeneration (RD) model.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Anatomy .
authors.forename: Seung Hee
authors.initials: SH
authors.lastname: Lee
authors.forename: Eojin
authors.initials: E
authors.lastname: Jeong
authors.forename: Sun-Sook
authors.initials: SS
authors.lastname: Paik
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Jeon
authors.forename: Sung Won
authors.initials: SW
authors.lastname: Jung
authors.forename: Hyun-Bok
authors.initials: HB
authors.lastname: Kim
authors.forename: Muyan
authors.initials: M
authors.lastname: Kim
authors.forename: Myung-Hoon
authors.initials: MH
authors.lastname: Chun
authors.forename: In-Beom
authors.initials: IB
authors.lastname: Kim
mesh_terms: D000477:Alkylating Agents / Q000633:toxicity; D000818:Animals; D000872:Anthocyanins / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D004195:Disease Models, Animal; D004596:Electroretinography; D005960:Glucosides / Q000494:pharmacology*; D008297:Male; D008770:Methylnitrosourea / Q000633:toxicity*; D031625:Morus / Q000737:chemistry*; D055254:Night Vision / Q000187:drug effects; D020419:Photoreceptor Cells, Vertebrate / Q000187:drug effects / Q000473:pathology; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012162:Retinal Degeneration / Q000139:chemically induced* / Q000188:drug therapy* / Q000473:pathology
chemical_list: D000477:Alkylating Agents; D000872:Anthocyanins; D005960:Glucosides; D010936:Plant Extracts; C462279:cyanidin-3-O-beta-glucopyranoside; D008770:Methylnitrosourea