title: Alpha-mangostin induces changes in glutathione levels associated with glutathione peroxidase activity in rat brain synaptosomes.
abstract: BACKGROUND
  In a previous report, we have characterized the antiperoxidative properties of alpha-mangostin in different toxic models tested in nerve tissue preparations.
  
  
  OBJECTIVE
  Here, the modulatory effects of this xanthone on the glutathione system  (reduced glutathione (GSH) levels, glutathione peroxidase (GPx), and glutathione S-transferase (GST) activities) were tested in synaptosomal P2 fractions isolated from rat brains in order to provide further information on key mechanisms exerted by this antioxidant in the nervous system.
  
  
  METHODS
  Synaptosomes were exposed to increasing concentrations of the xanthone, and also challenged to the toxic actions of a free radical generator, ferrous sulfate (FeSO(4)). For comparative purposes, the mitochondrial toxin 3-nitropropionic acid (3-NP) was also  explored.
  
  
  RESULTS
  Alpha-mangostin significantly decreased the levels of GSH, and increased GPx activity.
  
  
  CONCLUSIONS
  This finding was interpreted as a modulatory action of the GSH system in preparation to exert antioxidant responses. Although FeSO(4)  exhibited similar effects, these were interpreted as a compensatory response to the toxic actions of the pro-oxidant. We came to this conclusion based on our previous report where alpha-mangostin produced antiperoxidative effects and FeSO(4) produced oxidative damage to lipids. GST  activity remained unaffected by both the antioxidant and the pro-oxidant. Our results suggest that alpha-mangostin is able to modulate GPx activity as a potential antioxidant strategy, thereby transiently consuming GSH levels.
authors.affiliation: Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico.
authors.forename: Berenice
authors.initials: B
authors.lastname: Márquez-Valadez
authors.forename: Perla D
authors.initials: PD
authors.lastname: Maldonado
authors.forename: Sonia
authors.initials: S
authors.lastname: Galván-Arzate
authors.forename: Luis Alejandro
authors.initials: LA
authors.lastname: Méndez-Cuesta
authors.forename: Verónica
authors.initials: V
authors.lastname: Pérez-De La Cruz
authors.forename: José
authors.initials: J
authors.lastname: Pedraza-Chaverrí
authors.forename: María Elena
authors.initials: ME
authors.lastname: Chánez-Cárdenas
authors.forename: Abel
authors.initials: A
authors.lastname: Santamaría
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D001921:Brain / Q000378:metabolism*; D005296:Ferrous Compounds / Q000494:pharmacology; D029762:Garcinia mangostana / Q000737:chemistry*; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism; D008297:Male; D009574:Nitro Compounds / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology; D011422:Propionates / Q000494:pharmacology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism / Q000494:pharmacology; D013574:Synaptosomes / Q000187:drug effects* / Q000378:metabolism; D044004:Xanthones / Q000494:pharmacology*
chemical_list: D000959:Antihypertensive Agents; D000975:Antioxidants; D005296:Ferrous Compounds; D009574:Nitro Compounds; D011422:Propionates; D047428:Protein Kinase Inhibitors; D017382:Reactive Oxygen Species; D044004:Xanthones; C020748:ferrous sulfate; D005979:Glutathione Peroxidase; D005982:Glutathione Transferase; D005978:Glutathione; C015392:3-nitropropionic acid; C021053:mangostin