Parthenolide Relieves Pain and Promotes M2 Microglia/Macrophage Polarization in Rat Model of Neuropathy

Figure 1

The effect of PTL on allodynia (von Frey test) and hyperalgesia (cold plate test) in CCI-exposed rats. Naïve rats do not show symptoms of neuropathy ((a) and (b)). In CCI-exposed rats, PTL (5 μg/5 μL) and vehicle were i.t. administered preemptively 16 h and 1 h before CCI and once daily over 7 days. The response to PTL was measured 30 minutes after administration by the von Frey test (a) and 35 minutes after administration by the cold plate test (b) 1 day before CCI and then on days 3, 5, and 7 after injury. Repeated PTL administration diminished the development of neuropathic pain. PTL significantly reduced mechanical allodynia (a) and thermal hyperalgesia (b) on days 3, 5, and 7 after CCI. The data are presented as the mean response ± SEM (10–20 rats per group). The results of the experiments were statistically evaluated using one-way analyses of variance (ANOVA). The differences between the treatment groups throughout the study were further analyzed with Bonferroni’s post hoc tests. indicate significant differences compared to naïve rats. ^### indicate significant differences between vehicle-treated and PTL-treated CCI-exposed rats. N-naïve, V-vehicle, and PTL-parthenolide.

(a)

(b)