title: Purple rice extract and anthocyanidins of the constituents protect against light-induced retinal damage in vitro and in vivo.
abstract: This study evaluated the protective effects of purple rice ( Oryza sativa L.) bran extract (PRE) and its major anthocyanidins (cyanidin and peonidin) against light-induced retinal damage. In an in vitro experiment, cultured murine photoreceptor cells (661W) were damaged by a 24 h exposure to light. Viability of 661W after light treatment, assessed by the tetrazolium salt (WST-8) assay and Hoechst 33342 nuclear staining, was improved by the addition of PRE, cyanidin, and peonidin. Intracellular radical activation in 661W, evaluated using the reactive oxygen species (ROS) sensitive probe 5-(and 6)-chloromethyl-2,7-dichlorodihydrofluorescein diacetate acetyl ester (CM-H(2)DCFDA), was reduced by PRE and its anthocyanidins. Electron spin resonance (ESR) measurements showed that PRE, peonidin, and cyanidin all exhibited radical scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, superoxide anion radical ((•)O(2)(-)), and hydroxyl radical ((•)OH). In an in vivo mouse experiment, intravitreous injection of PRE significantly suppressed photoreceptor degeneration induced by exposure to light as revealed by histological analysis using hematoxylin-eosin staining. These findings suggest that PRE and its anthocyanidins possess protective effects with antioxidation mechanism in both in vitro and in vivo models of retinal diseases.
authors.affiliation: Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Tanaka
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Nakanishi
authors.forename: Kenjirou
authors.initials: K
authors.lastname: Ogawa
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Tsuruma
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Shimazawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shimoda
authors.forename: Hideaki
authors.initials: H
authors.lastname: Hara
mesh_terms: D000818:Animals; D000872:Anthocyanins / Q000008:administration & dosage / Q000494:pharmacology*; D004195:Disease Models, Animal; D006801:Humans; D008027:Light; D008297:Male; D051379:Mice; D012275:Oryza / Q000737:chemistry*; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D020011:Protective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D012160:Retina / Q000187:drug effects / Q000293:injuries / Q000528:radiation effects*; D012164:Retinal Diseases / Q000188:drug therapy*
chemical_list: D000872:Anthocyanins; D010936:Plant Extracts; D020011:Protective Agents