Table 5.

The effect of rhizome and leaf EOs on formalin-induced pain behavior and edema in mice at different concentrations.

Group	Phase I response		Phase II response		Paw volume (mL)
	Flinching (freq.)	Licking (sec.)	Flinching (freq.)	Licking (sec.)	Baseline	4 h after injection
Normal	2 ± 2	0	2 ± 2	0	0.16 ± 0.2	—
Formalin-2.5%	20 ± 3.45#	72 ± 6.78#	112 ± 10.67#	225 ± 13.14#	0.18 ± 0.4	0.32 ± 0.02∗
RO-5%	6 ± 0.44	22 ± 3.24	35 ± 5.33	102 ± 5.67	0.16 ± 0.2	0.20 ± 0.02∗
RO-1%	10 ± 0.23	34 ± 2.56	54 ± 2.34	156 ± 3.45	0.18 ± 0.2	0.23 ± 0.03∗
RO-0.25%	18 ± 0.45	45 ± 1.24	82 ± 4.78	198 ± 4.35	0.16 ± 0.4	0.27 ± 0.02∗
LO-5%	3 ± 0.45	18 ± 2.45	28 ± 5.23	76 ± 5.67	0.17 ± 0.2	0.18 ± 0.02∗
LO-1%	8 ± 0.34	32 ± 2.23	36 ± 2.76	112 ± 6.89	0.16 ± 0.2	0.21 ± 0.04∗
LO-0.25%	14 ± 0.56	40 ± 3.23	62 ± 5.45	154 ± 4.78	0.18 ± 0.4	0.24 ± 0.02∗
Diclofenac-1%	2 ± 0.21	12 ± 1.24	22 ± 2.34	54 ± 1.34	0.16 ± 0.2	0.17 ± 0.02∗

Data are mean ± SE. The numbers are frequencies (freq.) of flinching and total time (seconds; sec.) spent licking the formalin-injected paw. The behavioral response was measured at a total of 30 min after subplantar injection. p < 0.05 compared with the formalin-treated group (n = 6), ^#p < 0.05 compared with the normal group. Baseline values of paw volume represent preinjection diameters of paws. ^∗p < 0.05, compared with the formalin-treated group (n = 6) (ANOVA with Tukey's test). RO: rhizome EO; LO: leaf EO.