The carrageenan-induced peritonitis model

Mice were randomly distributed into twelve groups (n = 5/group). In order to evaluate the effect of CE and fractions on leukocyte recruitment into the peritoneal cavity, the mice were orally pre-treated with a vehicle (0.9% saline solution)/carrageenan group, CE or Fractions (50, 100 and 200 mg/kg), or Diclofenac (10 mg/kg). After 30 min, 0.25 ml of a 1% carrageenan solution (Sigma-Aldrich, São Paulo, Brazil) was intraperitoneally (i.p.) injected. The sham group received a vehicle (1 mL water/10 g, p.o) and a 0.9% sterile saline solution intraperitoneal injection (0.1 mL/10 g) [11]. Then, the mice were euthanized 4 h later with an overdose of 90 mg/kg sodium thiopental. Three mL of saline solution was then injected into each abdominal cavity and peritoneal fluid was collected and diluted (1:20) in Turk’s solution. A total leukocyte count was performed for each sample with a Neubauer counting chamber. The samples were stored at − 80 °C for subsequent analyses of myeloperoxidase (MPO) activity, as well as malondialdehyde (MDA) and total glutathione levels.