The suppressive effects of metformin on inflammatory response of otitis media model in human middle ear epithelial cells

Jae-Gu Cho, Jae-Jun Song, June Choi, Gi Jung Im, Hak Hyun Jung, Sungwon Chae

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


Objective Metformin is a well-known anti-diabetic agent, but its mechanism is unclear. Recently, many reports have described the anti-inflammatory effects of metformin on various cell types, including human vascular smooth muscle cells and endothelial cells. This study was designed to investigate the anti-inflammatory effect of metformin on lipopolysaccharide (LPS) induced inflammation in human middle ear epithelial cell lines (HMEECs). Methods The effect of pretreatment by metformin (0, 1, 2, 4 mM) was evaluated by the inflammatory response in the HMEECs exposed to LPS (10 ng/ml). For verifying the suppression effect of metformin on the inflammatory cytokines, tumor necrosis factor-alpha (TNF-α) was evaluated by real-time polymerase chain reaction, and COX-2 protein was assessed by western blotting. Intracellular reactive oxygen species (ROS) was measured using 2′, 7′-dichlorofluorescein diacetate (DCFHDA) fluorocytometer. Results Stimulation by LPS 10 ng/ml concentration showed 12.4 folds increase the expression of TNF-α mRNA compared to control on HMEECs. Pretreatment of metformin dose dependently suppressed the expression of TNF-α mRNA induced by LPS (2 mM, p = 0.03). The amount of COX-2 protein production was significantly decreased by metformin pretreatment (4 mM, p = 0.01). The production of ROS was decreased significantly by pretreatment of metformin (p = 0.03). Conclusions These findings suggest that the inflammatory response and oxidative stress induced by LPS could be suppressed by metformin in HMEECs. Therefore, metformin may have a therapeutic potential for the treatment of the otitis media.

Original languageEnglish
Pages (from-to)28-32
Number of pages5
JournalInternational Journal of Pediatric Otorhinolaryngology
Publication statusPublished - 2016 Oct 1


  • Human middle ear epitheilial cells
  • LPS
  • Metformin
  • Otitis media

ASJC Scopus subject areas

  • Otorhinolaryngology
  • Pediatrics, Perinatology, and Child Health

Fingerprint Dive into the research topics of 'The suppressive effects of metformin on inflammatory response of otitis media model in human middle ear epithelial cells'. Together they form a unique fingerprint.

Cite this