Figure 1.
Effect of CBD pretreatment (2.5, 5.0 mg·kg−1, i.p.) on PAC-induced mechanical allodynia in female C57Bl/6 mice. Baseline sensitivity to von Frey filaments was assessed on the day before drug administration and continued weekly for 10 weeks. Mice received the following two i.p. injections spaced 15 min apart on days 1, 3, 5 and 7: CRM vehicle, CRM vehicle; CRM vehicle, 4.0 mg·kg−1 PAC; CRM vehicle, 8.0 mg·kg−1 PAC; 2.5 mg·kg−1 CBD, 8.0 mg·kg−1 PAC; 5.0 mg·kg−1 CBD, 8.0 mg·kg−1 PAC. Two-way anova revealed significant main effects of treatment [F(4, 310) = 27.71, P < 0.0001] and time [F(9, 310) = 5.001, P < 0.001] and no significant interaction (F < 1.0). Bonferroni post-tests revealed a significant increase in sensitivity in both the 4.0 and 8.0 mg·kg−1 PAC groups compared with Veh/Veh. In contrast, the PAC groups pretreated with either 2.5 or 5.0 mg·kg−1 CBD were not significantly different from Veh/Veh in their mechanical sensitivity. X-axis: time points pre- or post-day first injection. Y-axis: threshold pressure to elicit hind paw withdrawal from von Frey filament. Data points represent the mean and SEM, n = 8 per group.