title: Astrocyte activation and neurotoxicity: A study in different rat brain regions and in rat C6 astroglial cells.
abstract: The present study was conducted to investigate the effect of rotenone on astrocytes activation, their viability and its effect on neuronal death in different brain regions. Rotenone was injected in rat brain by intracerebroventricularly (bilateral) route at dose of 6 μg and 12 μg. In vitro C6 cells were treated with rotenone at concentration of 0.1, 0.25, 0.5, 1 and 2 μM. Rotenone administration to rat brain caused significant astrocytes activation in frontal cortex, cerebellum, cerebellar nucleus, substantia nigra, hypothalamus and hippocampus regions of the rat brain. Rotenone administration also led to significant degeneration of cells in all the studied regions along with altered nuclear morphology assessed by hematoxylin-eosin and cresyl violet staining. Histological staining showed the significantly decreased number of cells in all the studied regions except cerebellar nucleus in dose and time dependant manner. Rotenone administration in the rat brain also caused significant decrease in glutathione levels and augmented nitrite levels. In vitro treatment of rotenone to astrocytic C6 cells caused significantly increased expression of glial fibrillar acidic protein (GFAP) and decreased viability in dose and time dependent manner. Rotenone treatment to C6 cells exhibited significant generation of reactive oxygen species, augmented nitrite level, impaired mitochondrial activity, apoptotic chromatin condensation and DNA damage in comparison to control cells. Findings showed that oxidative stress play a considerable role in rotenone induced astrocyte death that was attenuated with co-treatment of antioxidant melatonin. In conclusion, results showed that rotenone caused significant astrocytes activation, altered nuclear morphology, biochemical alteration and apoptotic cell death in different rat brain regions. In vitro observations in C6 cells showed that rotenone treatment exhibited oxidative stress mediated apoptotic cell death, which was attenuated with co treatment of melatonin.
authors.affiliation: Toxicology Division, CSIR-CDRI, Lucknow 226031, India; Academy of Scientific & Innovative Research (AcSIR), India.
authors.forename: Poonam
authors.initials: P
authors.lastname: Goswami
authors.affiliation: Toxicology Division, CSIR-CDRI, Lucknow 226031, India; Academy of Scientific & Innovative Research (AcSIR), India.
authors.forename: Sonam
authors.initials: S
authors.lastname: Gupta
authors.affiliation: Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA.
authors.forename: Neeraj
authors.initials: N
authors.lastname: Joshi
authors.affiliation: Toxicology Division, CSIR-CDRI, Lucknow 226031, India.
authors.forename: Sharad
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Toxicology Division, CSIR-CDRI, Lucknow 226031, India; Academy of Scientific & Innovative Research (AcSIR), India. Electronic address: sarika_singh@cdri.res.in.
authors.forename: Sarika
authors.initials: S
authors.lastname: Singh
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects*; D001921:Brain / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002478:Cells, Cultured; D005978:Glutathione / Q000378:metabolism; D008550:Melatonin / Q000494:pharmacology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D009573:Nitrites / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012402:Rotenone / Q000494:pharmacology
chemical_list: D009573:Nitrites; D012402:Rotenone; D005978:Glutathione; D008550:Melatonin
keywords: Astrocyte activation; DNA damage; Melatonin; Nitrite level; Reactive oxygen species; Rotenone