Fig. 2
Effect of individual curcumin, piperine, and curcumin-piperine combination on pain-like behaviors in the mouse formalin model. Formalin-induced pain-like behaviors are expressed in the time course of hind paw licking behaviors and the total duration of licking behaviors in phase I (0–5 min after formalin injection) and phase II (10–40 min after formalin injection). Schematic presentation of the experimental design (A, B). Hind paw licking durations of mice treated with curcumin (C), piperine (D), and curcumin-piperine combination (E). Data are expressed as mean ± S.E.M (n = 8 mice/group). The differences between the vehicle-treated group and treatment groups were analyzed using one-way ANOVA followed by Dunnett’s post hoc test. ***p < 0.001; **p < 0.01; *p < 0.05. CMC, carboxymethyl cellulose; Cur, curcumin; Pip, piperine. The 1/16, 1/8, ¼ and ½ ED50 correspond to 5.6, 11.2, 22.5 and 44.9 mg/kg of curcumin-piperine combination