title: Effects of silibinin hemisuccinate on the intraocular pressure in normotensive rabbits.
abstract: OBJECTIVE
  To evaluate the effects of silibinin hemisuccinate on the normal intraocular pressure (IOP) in rabbits.
  
  
  METHODS
  This study took place in the Department of Pharmacology and Toxicology, College of Pharmacy, University of Baghdad during the period from January to June 2005. Twenty-five New Zealand white rabbits weighing 1.5-2.5 kg were used in this study. The effects of corneal instillation of various concentrations of silibinin hemisuccinate (0.5%, 0.75% and 1%) dissolved in arachis oil, on the normal intraocular pressure in rabbits were evaluated using indentation tonometry; in addition to the possible modulation of normal IOP-recovery time after intravenous infusion of 20% sodium chloride solution.
  
  
  RESULTS
  The results showed that within 30 minutes of application, silibinin in various concentrations significantly reduces IOP in comparison to baseline values (p<0.05), with greater reduction being achieved with 0.75%. The effect of IOP reduction lasts 2-3 hours and proportionate to the concentration used. Moreover, remarkable delay in IOP recovery was observed after instillation of silibinin compared with the vehicle treated (arachis oil) animals, indicating interference with aqueous humor formation.
  
  
  CONCLUSIONS
  The results obtained in this study provide experimental evidences for the effectiveness of silibinin in the reduction of IOP and possible modulation of its regulatory mechanisms.
authors.affiliation: Department of Pharmacology and Toxicology, College of Pharmacy, University of Baghdad, Baghdad, Iraq.
authors.forename: Haider M
authors.initials: HM
authors.lastname: Mohammed
authors.forename: Munaf H
authors.initials: MH
authors.lastname: Abdulrazzaq
authors.forename: Saad A
authors.initials: SA
authors.lastname: Hussain
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D007322:Instillation, Drug; D007429:Intraocular Pressure / Q000187:drug effects*; D011817:Rabbits; D000077385:Silybin; D012838:Silymarin / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D012838:Silymarin; D000077385:Silybin