Effect of a supercritical CO2 extract of Aloysia gratissima leaves (EAG) in the acetic acid-induced abdominal writhing test in mice. V: vehicle treated group (0.9% NaCl + 1% Tween, 10 mL/kg p.o., n = 8). INDO: indomethacin (10 mg kg p.o., n = 6) or EAG (1, 10 and 30 mg/kg p.o., n = 6–8), 1 h prior to acetic acid administration. Each column represents the mean ± S.E.M. One-way ANOVA followed by the Student-Newman-Keuls test, ∗∗p < 0.01 and ∗p < 0.05 different from the vehicle group; ###p < 0.001 and ##p < 0.01 different from the INDO group.