title: The effect of methylene blue treatment on aspiration pneumonia.
abstract: BACKGROUND
  The study aimed to examine whether methylene blue (MB) prevents different pulmonary aspiration materials-induced lung injury in rats.
  
  
  METHODS
  The experiments were designed in 60 Sprague-Dawley rats, ranging in weight from 250-300 g, randomly allotted into one of six groups (n = 10): saline control, Biosorb Energy Plus (BIO), hydrochloric acid (HCl), saline + MB treated, BIO + MB treated, and HCl + MB treated. Saline, BIO, and HCl were injected into the lungs in a volume of 2 mL/kg. After surgical procedure, MB was administered intraperitoneally for 7 days at a daily dose of 2 mg/kg per day. Seven days later, rats were killed, and both lungs in all groups were examined biochemically and histopathologically.
  
  
  RESULTS
  Our findings show that MB inhibits the inflammatory response reducing significantly (P < 0.05) peribronchial inflammatory cell infiltration, alveolar septal infiltration, alveolar edema, alveolar exudate, alveolar histiocytes, interstitial fibrosis, granuloma, and necrosis formation in different pulmonary aspiration models. Pulmonary aspiration significantly increased the tissue hydroxyproline content, malondialdehyde levels, and decreased (P < 0.05) the antioxidant enzyme (superoxide dismutase and glutathione peroxidase) activities. MB treatment significantly (P < 0.05) decreased the elevated tissue hydroxyproline content and malondialdehyde levels and prevented the inhibition of superoxide dismutase and glutathione peroxidase (P < 0.05) enzymes in the tissues. Furthermore, there is a significant reduction in the activity of inducible nitric oxide synthase (iNOS), terminal deoxynucleotidyl transferase dUTP nick end labeling, and arise in the expression of surfactant protein D in lung tissue of different pulmonary aspiration models with MB therapy.
  
  
  CONCLUSIONS
  MB treatment might be beneficial in lung injury and therefore shows potential for clinical use.
authors.affiliation: Department of Histology and Embryology, Faculty of Medicine, Istanbul Medeniyet University, Istanbul, Turkey. Electronic address: mkanter65@yahoo.com.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Kanter
authors.affiliation: Department of Anesthesiology and Reanimation, Faculty of Medicine, Trakya University, Edirne, Turkey.
authors.forename: Sevtap Hekimoglu
authors.initials: SH
authors.lastname: Sahin
authors.affiliation: Department of Pediatric Surgery, Faculty of Medicine, Trakya University, Edirne, Turkey.
authors.forename: Umit Nusret
authors.initials: UN
authors.lastname: Basaran
authors.affiliation: Department of Pediatric Surgery, Faculty of Medicine, Trakya University, Edirne, Turkey.
authors.forename: Suleyman
authors.initials: S
authors.lastname: Ayvaz
authors.affiliation: Department of Pediatric Surgery, Faculty of Medicine, Trakya University, Edirne, Turkey.
authors.forename: Burhan
authors.initials: B
authors.lastname: Aksu
authors.affiliation: Department of Histology and Embryology, Faculty of Medicine, Namik Kemal University, Tekirdag, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Erboga
authors.affiliation: Department of Anesthesiology and Reanimation, Faculty of Medicine, Trakya University, Edirne, Turkey.
authors.forename: Alkin
authors.initials: A
authors.lastname: Colak
mesh_terms: D055371:Acute Lung Injury / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D000818:Animals; D004353:Drug Evaluation, Preclinical; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008168:Lung / Q000473:pathology; D008751:Methylene Blue / Q000627:therapeutic use*; D011015:Pneumonia, Aspiration / Q000150:complications* / Q000188:drug therapy / Q000473:pathology; D011897:Random Allocation; D017207:Rats, Sprague-Dawley
chemical_list: D004791:Enzyme Inhibitors; D008751:Methylene Blue
keywords: Methylene blue; Pulmonary aspiration; Surfactant protein D; TUNEL; iNOS