Fig. 2.

The reversal effect of 8 mg/kg (i.p.) AM251 on 300 mg/kg (i.p.) protocatechuic acid and 5 mg/kg (i.p.) WIN 55,212–2 induced antinociception in the tail-immersion test. PCA: Protocatechuic acid. MPE: Maximum possible effect. WIN: WIN 55,212–2. ^*P < 0.05, ^***P < 0.001: significant difference based on the control group. ⁺⁺⁺P < 0.001: significant difference based on the 300PCA group. ^&&&P < 0.001: significant difference based on the WIN group. One-way ANOVA followed by Tukey’s HSD multiple comparison post-hoc test was performed. Values expressed as mean ± S.E.M. (n = 8)