Doxycycline attenuated lung injury by its biological effect apart from its antimicrobial function

Masaki Fujita, Eiji Harada, Satoshi Ikegame, Qing Ye, Hiroshi Ouchi, Ichiro Inoshima, Yoichi Nakanishi

Research output: Contribution to journalArticle

16 Citations (Scopus)


Antibiotics can have a biological effect apart from their anti-bacterial effect. We hypothesized that doxycycline could attenuate acute lung injury through its biological effect. Lipopolysaccharide or doxycycline-resistant Streptococcus pneumoniae was administered intratracheally into mice with the co-administration of doxycycline. Thereafter, the lung pathology, intraalveolar inflammatory cells, bacterial number, and matrix metalloproteinases were investigated. Matrix metalloproteinases, neutrophil migration, and alveolar destruction were induced by lipopolysaccharide. Doxycycline was thus found to improve all of these symptoms. In addition, an inhibitor of matrix metalloproteinases, CGS27023A, attenuated lipopolysaccharide-induced lung injury. Doxycycline also attenuated the lung injury induced by doxycycline-resistant S. pneumoniae and improved the mortality rate although the bacterial number in the lung did not change. Our data indicated that doxycycline could attenuate acute lung injury through a biological effect that was different from its antibiotic effect.

Original languageEnglish
Pages (from-to)669-675
Number of pages7
JournalPulmonary Pharmacology and Therapeutics
Issue number6
Publication statusPublished - Dec 1 2007


All Science Journal Classification (ASJC) codes

  • Pulmonary and Respiratory Medicine
  • Biochemistry, medical
  • Pharmacology (medical)

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