Abstract
Gallic acid Inhibits M1 Macrophage Polarization via Adenosine 5’-Monophosphate-Activated Protein Kinase/Signal Transducers and Activators of Transcription 1 Pathway
Department of Periodontics, School of Stomatology of Jinzhou Medical College, 1Key Laboratory of Brain and Spinal Cord Injury, First Affiliated Hospital, Jinzhou Medical University, Linghe, Jinzhou 121000, China
Correspondence Address:
Linyuan Wang, Department of Periodontics, School of Stomatology of Jinzhou Medical College, Linghe, Jinzhou 121000, China, E-mail: wang_linyuan@outlook.com
To investigate the role of gallic acid in lipopolysaccharide/interferon-gamma induced macrophage polarization toward M1. Macrophages were isolated from peritoneal wash fluid and exposed to gallic acid prepared at the concentrations of control, 6.25, 12.5, 25 and 37.5 μg/ml, in presence of lipopolysaccharide and interferon-gamma, for establishment of M1 polarization. Adenosine 5’-monophosphate-activated protein kinase inhibitor compound C was used to pre-treat the macrophages; cell viability was determined by flow cytometry with Annexin V-PE/7-amino actinomycin D staining, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and trypan blue assays; flow cytometry was applied to evaluate the expression of F4/80+ inducible nitric oxide synthase+ M1 macrophages; real-time polymerase chain reaction was used to assess the messenger ribonucleic acid expression level of inducible nitric oxide synthase, tumor necrosis factor-alpha and interleukin-1beta. Protein expression levels of cyclooxygenase-2, adenosine 5‘-monophosphate-activated protein kinase, signal transducers and activators of transcription 1 and phosphorylation levels of adenosine 5’-monophosphate-activated protein kinase and signal transducers and activators of transcription 1 were evaluated by Western blotting. Gallic acid at the concentrations of 6.25-37.5 μg/ml showed no noticeable effects on macrophages viability, but significantly decreased F4/80+ inducible nitric oxide synthase+ M1 macrophages polarization and the expression levels of inducible nitric oxide synthase, tumor necrosis factoralpha, interleukin-1 beta, cyclooxygenase-2 and phospho-signal transducers and activators of transcription 1, meanwhile increased the expression levels of p-adenosine 5’-monophosphate-activated protein kinase contents in a concentration-dependent manner. Adenosine 5’-monophosphate-activated protein kinase inhibitor compound C pre-treatment can reverse the effects of gallic acid on M1 macrophage polarization. Gallic acid may inhibit macrophage polarization toward M1 via adenosine 5’-monophosphate-activated protein kinase/signal transducers and activators of transcription 1 signaling pathway.
