title: Lycium barbarum polysaccharides attenuates N-methy-N-nitrosourea-induced photoreceptor cell apoptosis in rats through regulation of poly (ADP-ribose) polymerase and caspase expression.
abstract: BACKGROUND
  Lycium barbarum L., popularly known as "Goji berry", a classic of Traditional Chinese Medicine has long been used to treat ocular diseases and cardiovascular diseases. Recently, the photoreceptor cell protection of Lycium barbarum polysaccharides (LBP), a water extract from Lycium barbarum L. has received more attention. The present study was designed to investigate the effect of LBP on N-methyl-N-nitrosourea (MNU)-induced photoreceptor cell apoptosis, and the involvement of the poly (ADP-ribose) polymerase (PARP) and caspase.
  
  
  METHODS
  Photoreceptor cell injury was induced in male Sprague-Dawley rats by an intraperitoneal injection of MNU 60mg/kg. Seven days prior to MNU injection, LBP were intragastrical administered daily, rats were sacrificed at 24h and 7 days after MNU injection. Retinal morphologies, photoreceptor cells apoptosis, and protein expression were evaluated at 24h and 7 days after MNU injection.
  
  
  RESULTS
  Morphologically, the outer nuclear layer was well preserved in the LBP-treated rat retinas throughout the experimental period. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-digoxigenin nick-end labeling (TUNEL) assays showed that LBP could significantly suppress the loss of photoreceptor cells, as determined by the photoreceptor cell ratio at the central retina 24h and 7 days after MNU administration. Western-blot analysis demonstrated the expression levels of procaspase-9, -7, -3 and cleaved caspase-9, -7, -3 were upregulated, and PARP were downregulated both 24h and 7 days after MNU injection. LBP treatment significantly decreased protein levels of procaspase and cleaved caspase, increased the level of PARP and cleaved PARP on 24h and 7 days.
  
  
  CONCLUSIONS
  LBP inhibits MNU-induced rat photoreceptor cell apoptosis and protects retinal structure via the regulation of the expressions of PARP and caspase.
authors.affiliation: Department of Pharmacology, School of Pharmacy, Ningxia Medical University, 1160 Shengli Street, Yinchuan, Ningxia 750004, PR China; Key laboratory of Hui Ethnic Medicine Modernization, Ministry of Education, Ningxia Medical University, Yinchuan 750004, PR China.
authors.forename: Yafei
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Pharmacology, School of Pharmacy, Ningxia Medical University, 1160 Shengli Street, Yinchuan, Ningxia 750004, PR China; Key laboratory of Hui Ethnic Medicine Modernization, Ministry of Education, Ningxia Medical University, Yinchuan 750004, PR China.
authors.forename: Qipeng
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Departments of Pharmacy, General Hospital of Ningxia Medical University, 803 Shengli Street, Yinchuan, Ningxia 750004, PR China.
authors.forename: Hua
authors.initials: H
authors.lastname: Gao
authors.affiliation: Department of Pharmacology, School of Pharmacy, Ningxia Medical University, 1160 Shengli Street, Yinchuan, Ningxia 750004, PR China; Key laboratory of Hui Ethnic Medicine Modernization, Ministry of Education, Ningxia Medical University, Yinchuan 750004, PR China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Peng
authors.affiliation: Departments of Pharmacy, General Hospital of Ningxia Medical University, 803 Shengli Street, Yinchuan, Ningxia 750004, PR China. Electronic address: nxwym@163.com.
authors.forename: Youmin
authors.initials: Y
authors.lastname: Wen
authors.affiliation: Department of Pharmaceutical Engineering, School of Chemical and Materials Engineering, Kaili University, Kaiyuan Road, Kaili, Guizhou 556011, PR China. Electronic address: daiguidong@163.com.
authors.forename: Guidong
authors.initials: G
authors.lastname: Dai
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D020169:Caspases / Q000378:metabolism*; D019610:Cytoprotection; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000302:isolation & purification / Q000494:pharmacology*; D004789:Enzyme Activation; D032305:Lycium / Q000737:chemistry*; D008297:Male; D008770:Methylnitrosourea; D020419:Photoreceptor Cells, Vertebrate / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D008517:Phytotherapy; D010946:Plants, Medicinal; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D020011:Protective Agents / Q000302:isolation & purification / Q000494:pharmacology*; D017207:Rats, Sprague-Dawley; D012162:Retinal Degeneration / Q000139:chemically induced / Q000201:enzymology / Q000473:pathology / Q000517:prevention & control*; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors
chemical_list: D004365:Drugs, Chinese Herbal; D020011:Protective Agents; C500223:lycium barbarum polysaccharide; D008770:Methylnitrosourea; D011065:Poly(ADP-ribose) Polymerases; D020169:Caspases
keywords: Apoptosis; Caspase; DAPI (PubChem CID:2954); Dithiothreitol (PubChem CID: 446094); Eosin (PubChem CID: 11048); Formalin (PubChem CID: 712); Hematoxylin (PubChem CID: 442514); Lycium barbarum polysaccharide; N,N'-Methylenebisacrylamide (PubChem CID: 8041); N-Methyl-N-nitrosourea (PubChem CID: 12699); N-methyl-N-nitrosourea; PMSF (PubChem CID: 4784); Photoreceptor cell; Poly (ADP-Ribose) polymerase; Rat; SDS (PubChem CID:3423265); Tris base (PubChem CID:6503)