title: Arabinogalactan as active compound in the management of corneal wounds: in vitro toxicity and in vivo investigations on rabbits.
abstract: OBJECTIVE
  Aims of the present investigation were to prove that natural polysaccharide arabinogalactan (AG) is well tolerated after ocular administration and exerts a high restoring effect on corneal epithelium abrasions.
  
  
  METHODS
  AG interactions with corneal cells, as well as its effect on their proliferation, were evaluated employing rabbit corneal epithelial cell cultures. The effects due to the presence of benzalkonium chloride (BAK) were also studied on cell cultures, ex vivo on rabbit isolated corneas, evaluating the hydration level, and on the healing rate of experimental corneal wounds in rabbits. Furthermore, the healing process of corneal lesions treated with an experimental 5.0% AG solution was studied and compared with those obtained applying solutions of hyaluronic acid and tamarind seed polysaccharide, both chosen as a reference by virtue of their well-known adjuvant properties on corneal trophism; the study was carried out by light and transmission electron microscopy.
  
  
  RESULTS
  BAK showed toxic effects on corneal epithelium in all experiments. AG proved to stimulate the growth of the corneal epithelial cells by interacting at the level of the cell plasma membrane. The microscopy observations of the epithelial surface of AG-treated damaged corneas revealed a well-restored and histologically organized ultrastructure characterized by fully formed microvilli and glycocalyx; the healing process resulted faster with respect to spontaneously recovered untreated corneas.
  
  
  CONCLUSIONS
  Our results suggest that AG can interact with corneal epithelial cells without any toxic side effect; moreover, it proved to stimulate cell proliferation, thus promoting tissue re-epithelialization and reorganization just 48 hr post-wounding.
authors.affiliation: Department of Pharmaceutical Sciences, University of Pisa, Via Bonanno 33, Pisa, Italy. burgal@farm.unipi.it
authors.forename: Susi
authors.initials: S
authors.lastname: Burgalassi
authors.forename: Nadia
authors.initials: N
authors.lastname: Nicosia
authors.forename: Daniela
authors.initials: D
authors.lastname: Monti
authors.forename: Giulia
authors.initials: G
authors.lastname: Falcone
authors.forename: Enrico
authors.initials: E
authors.lastname: Boldrini
authors.forename: Ortenzio
authors.initials: O
authors.lastname: Fabiani
authors.forename: Carla
authors.initials: C
authors.lastname: Lenzi
authors.forename: Andrea
authors.initials: A
authors.lastname: Pirone
authors.forename: Patrizia
authors.initials: P
authors.lastname: Chetoni
mesh_terms: D000818:Animals; D001548:Benzalkonium Compounds / Q000633:toxicity; D002057:Burns, Chemical / Q000188:drug therapy* / Q000473:pathology; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003315:Cornea / Q000187:drug effects / Q000473:pathology; D004338:Drug Combinations; D019573:Epithelium, Corneal / Q000166:cytology / Q000187:drug effects*; D005126:Eye Burns / Q000139:chemically induced* / Q000473:pathology; D005260:Female; D005685:Galactans / Q000627:therapeutic use* / Q000633:toxicity; D019850:Heptanol / Q000633:toxicity; D008856:Microscopy, Fluorescence; D011817:Rabbits; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D001548:Benzalkonium Compounds; D004338:Drug Combinations; D005685:Galactans; D019850:Heptanol; C005653:arabinogalactan