title: Melatonin treatment reduces astrogliosis and apoptosis in rats with traumatic brain injury.
abstract: OBJECTIVE
  Melatonin is known as an anti-inflammatory agent, and it has been proven to exert neuroprotection through inhibition of cell death (apoptosis) in several models of brain injury. Secondary injury following the primary traumatic brain injury (TBI) results in glial cells activation, especially astrocytes. In fact, astrocyte activation causes the production of pro-inflammatory cytokines that may lead to secondary injury. Since most TBI research studies have focused on injured neurons and paid little attention to glial cells, the aim of current study was to investigate the effects of melatonin against astrocytes activation (astrogliosis), as well as inhibition of apoptosis in brain tissue of male rats after TBI.
  
  
  METHODS
  The animals were randomly allocated into five groups: sham group, TBI+ vehicle group (1% ethanol in saline) and TBI+ melatonin groups (5 mg/kg, 10 mg/kg and 20 mg/kg). All rats were intubated and then exposed to diffuse TBI, except for the sham group. Immunohistochemical methods were conducted using glial fibrillary acidic protein (GFAP) marker and TUNEL assay to evaluate astrocyte reactivity and cell death, respectively.
  
  
  RESULTS
  The results showed that based on the number of GFAP positive astrocytes in brain cortex, astrogliosis was reduced significantly (P<0.05) in melatonin- treated groups (no dose dependent) compared to the vehicle group. Furthermore, based on TUNEL results, melatonin treatment considerably reduced the number of apoptotic cells (P<0.05).
  
  
  CONCLUSIONS
  In total, the present findings suggest that melatonin treatment following TBI diminishes astrocyte reactivity and neuronal cells apoptosis in brain cortex in the rat model.
authors.affiliation: Department of Anatomical Sciences, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Abdolreza
authors.initials: A
authors.lastname: Babaee
authors.affiliation: Department of Anatomical Sciences, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Seyed Hassan
authors.initials: SH
authors.lastname: Eftekhar-Vaghefi
authors.affiliation: Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Asadi-Shekaari
authors.affiliation: Department of Physiology, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Nader
authors.initials: N
authors.lastname: Shahrokhi
authors.affiliation: Department of Anatomical Sciences, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Samereh Dehghani
authors.initials: SD
authors.lastname: Soltani
authors.affiliation: Department of Pathology, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Malekpour-Afshar
authors.affiliation: Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Basiri
keywords: Apoptosis; Astrogliosis; GFAP; Melatonin; Traumatic brain injury