Figure 1
From: Gastrodin protects against chronic inflammatory pain by inhibiting spinal synaptic potentiation
Intraperitoneal (i.p.) administration of GAS attenuated the development of spontaneous pain, mechanical and thermal pain hypersensitivity induced by paw inflammation.
(A,B) The dose-dependent inhibitory effect of i.p. GAS (50, 100 and 200 mg/kg body weight) on the time course (A) and total response duration (B) of bee-venom-induced spontaneous pain (n = 8, P < 0.05). (C) The analgesic effect of GAS was not reversed by naloxone, an opioid receptor antagonist (n = 5, P > 0.05). (D) Representative traces showing the attenuation of CFA-induced mechanical pain hypersensitivity by i.p. GAS (200 mg/kg) at different time points after GAS administration. (E, F) Quantitative summary of the inhibition of i.p. GAS (50, 100 and 200 mg/kg) on the drop of paw withdrawal mechanical threshold (PWMT) (E), represented as integrated area under the curve, AUC, in (F) induced by CFA inflammation, indicating an analgesic effect on mechanical pain hypersensitivity (n = 8, P < 0.05). (G) Quantitative summary showing depression of thermal hyperalgesia by i.p. GAS (50, 100 and 200 mg/kg), manifesting as a prolonged paw withdrawal thermal latency (PWTL) to radiant heat stimuli compared to vehicle (n = 8, P < 0.05). (H,I) Neither basal nociception to mechanical and thermal stimuli (H) nor motor coordination (I) was altered by i.p. GAS (200 mg/kg) (n = 8, P > 0.05). All data are represented as mean ± S.E.M. *P < 0.05. PWMT, paw withdrawal mechanical threshold; PWTL, paw withdrawal thermal latency.
