Levo-Tetrahydropalmatine Attenuates Bone Cancer Pain by Inhibiting Microglial Cells Activation

Figure 1

Dose-dependent inhibitory effects of L-THP on TCI-induced thermal hyperalgesia and mechanical allodynia. Thermal hyperalgesia (a, c, and e) and mechanical allodynia (b, d, and f) are shown in the hind paw ipsilateral to TCI. L-THP at different doses (20, 40, and 60 mg/kg, dissolved in saline with 0.5% DMSO, 2 mL/rat) were administered intragastrically on postoperative days 3, 4, and 5 (a and b) or 7, 8, and 9 (c and d), or 11, 12, and 13 (e and f) indicated by arrows, respectively. Single administration of L-THP (60 mg/kg) was applied at postoperative day 11 (g and h). Arrows represent the time points of L-THP administration. Eight rats were included in each group. and indicate significant differences compared with sham group. and indicate significant differences compared with TCI group.

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