Fig. 5.

Suppression of capsaicin-induced pain by p.o. administration of EHE. a Mice were orally administered 700 mg/kg of EHE (closed circle) or water (closed square). After 0, 0.25, 0.5, 1, 2, 6, and 24 h, the mice were injected with 10 µl of solution (DMSO:Tween-80:physiological saline = 1:1:8) containing 0.06 mM capsaicin into the plantar surface of left hind paw. b Mice were orally administered 87.5–700 mg/kg of EHE. After 30 min, the mice were injected with 10 µl of solution (DMSO:Tween-80:physiological saline = 1:1:8) containing 0.18 μg/paw capsaicin into the plantar surface of left hind paw. Licking behaviors were observed for 5 min. Data represent the mean ± standard error of a 4–8 and b 3–4 mice. Statistical significance was determined with a Student’s t test; *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001 vs the water group and b Dunnett’s test; *p < 0.05 vs vehicle group (Veh)