Table 2.

Effects of methanol acetate fraction of P. stratiotes on hind paw licking in the formalin test in mice

Groups	Dose (mg/kg)	Early phase	% protection	Late phase	% protection
Group I	Methanol	40 ± 3.29	—	25.50 ± 2.41
Group II	10 (standard)	11.25 ± 0.98	71.88	8.25 ± 0.98b	67.65
Group III	200	20 ± 1.19	50	11.50 ± 1.82	54.90
Group IV	400	11.5 ± 1.82b	71.25	7.25 ± 2.33a	71.57

Values are expressed at means ± SEM (n = 5).

^a P < 0.05, and ^b P < 0.01, compared with control (one‐way ANOVA followed by Dunnett's t test). Group I animals received vehicle (1% Tween 80 in water), group II received indomethacin (10 mg/kg body weight), and groups III and IV were treated with, respectively, 200 and 400 mg/kg methanol acetate fraction of P. stratiotes.