Protective effects of melatonin against oxidation of guanine bases in DNA and decreased microsomal membrane fluidity in rat liver induced by whole body ionizing radiation

M. Karbownik, R. J. Reiter, W. Qi, J. J. Garcia, D. X. Tan, L. C. Manchester, Vijayalaxmi

Research output: Contribution to journalArticle

64 Scopus citations


The aim of the study was to examine the potential protective effect of melatonin against whole body ionizing radiation (800 cGy). Changes in 8-hydroxy-2'-deoxyguanosine (8-OH-dG) levels, an index of DNA damage, and alterations in membrane fluidity (the inverse of membrane rigidity) and lipid peroxidation in microsomal membranes, as indices of damage to lipid and protein molecules in membranes, were estimated. Measurements were made in rat liver, 12 h after their exposure to radiation. To test the potential protective effects of melatonin, the indole was injected (i.p. 50 mg/kg b.w.) at 120, 90, 60 and 30 min prior to radiation exposure. Both 8-OH-dG levels and microsomal membrane rigidity increased significantly 12 h after radiation exposure. Melatonin completely counteracted the effects of ionizing radiation. Changes in 8-OH-dG levels and membrane fluidity are early sensitive parameters of DNA and microsomal membrane damage, respectively, induced by ionizing radiation and our findings document the protective effects of melatonin against ionizing radiation.

Original languageEnglish (US)
Pages (from-to)137-144
Number of pages8
JournalMolecular and Cellular Biochemistry
Issue number1-2
StatePublished - Oct 13 2000



  • 8-hydroxy-2'-deoxyguanosine
  • Free radicals
  • Ionizing radiation
  • Lipid peroxidation
  • Melatonin
  • Membrane fluidity

ASJC Scopus subject areas

  • Molecular Biology
  • Clinical Biochemistry
  • Cell Biology

Cite this