Photobiomodulation reduces neutrophil migration and oxidative stress in mice with carrageenan-induced peritonitis

The purpose of the study is to investigate the effects of two doses of photobiomodulation (PBM) on inflammatory parameters including cell migration and oxidative stress in carrageenan-induced peritonitis models. Twenty-eight mice were divided into four groups: saline; untreated carrageenan (Cg; inflammation induced); and PMB treatment groups L1 and L5 (inflammation induced with carrageenan followed by laser irradiation at 1 and 5J/cm(2), respectively). After 30min of inducing inflammation, laser irradiation was administered every hour, for 4h. Peritoneal fluid was collected for analyses. The total leukocyte number in the peritoneal fluid in L1 (4.33 +/- 2.34) and L5 (4.95 +/- 2.86) after PBM was lower than that in Cg (10.93 +/- 5.15cells/ml). The average differential count of neutrophils in the Cg was 9.46 +/- 4.31cells/ml, which was higher than that in L1 (3.7 +/- 2.08) and L5 (4.94 +/- 2.57). Myeloperoxidase activity was also lower in L1 (1.89 +/- 0.43) and L5 (4.84 +/- 2.62) than in Cg (22.92 +/- 4.52UMPO/ml). Malondialdehyde content was lower in L1 (137.5 +/- 12.33) and L5 (169.6 +/- 22.77) than in Cg (345.7 +/- 65.67nmol/ml). Glutathione peroxidase concentration was significantly higher in L1 (155.2 +/- 12.43) and L5 (145.9 +/- 9.585) than in Cg (79.75 +/- 9.567/ml). Nitrite concentration was lower in L1 (0.3317M +/- 0.0669) and L5 (0.2429M +/- 0.0232) than in Cg (0.8380M +/- 0.01615). Laser irradiation at 1 and 5J/cm(2) reversed the inflammation (as indicated by neutrophil infiltration and oxidative stress).