Effects of honokiol and magnolol on CHPG-induced thermal hyperalgesia in mice. Honokiol (0.1-1.0 μg/paw), magnolol (0.05-0.5 μg/paw) and vehicle were administered 20 min prior to CHPG (1 μg) injection into hindpaw. The paw withdrawal latency in the 47°C water was measured during 5-120 min after intraplantar injection of CHPG. Each point represents the mean ± S.E.M. (n = 7-19). * indicates significantly different from vehicle group, *p < 0.05.