Phytochemical screening and analgesic profile of the lyophilized aqueous extract obtained from Chrysobalanus icaco leaves in experimental protocols

Figures & data

Figure 1. Chromatographic profile of the lyophilized aqueous extract obtained from C. icaco leaves (AEC). Conditions for elution: mobile phase methanol–water (5–100%), 1 h, C18 analytical column (25 cm × 0.46 mm, 5 μm), detection at 330 nm DAD-UV-Vis, 1 mL/min.

Figure 3. Time–response curve for the anti-nociceptive effect of the lyophilized aqueous extract obtained from C. icaco leaves (AEC; 400 mg/kg, p.o.) on acetic acid-induced writhing response in mice. Writhings were counted over 15 min following i.p. injection of acetic acid (0.8%). AEC (400 mg/kg, p.o.) was administered p.o. 0.5, 1, 2, 4, 8 or 24 h before acid acetic injection (0.8%). Control animals received an injection of vehicle by p.o. route. Each column represents mean ± SEM (n = 8, per group). *p < 0.05 versus control (ANOVA followed by Tukey’s test).

Table 1. Effect of the lyophilized aqueous extract obtained from C. icaco leaves (AEC) or indomethacin (INDO), reference drug, on writhing induced by acetic acid- and formalin-induced nociceptive behaviour in mice.

		Writhing test	Formalin test
Treatment	Dose(mg/kg)	Number of writhings^a	0–5 min^a	15–35 min^a
Vehicle	–	24.7 ± 4.7	48.5 ± 6.9	121.9 ± 18.5
AEC	100	11.4 ± 3.6^b	39.3 ± 5.8	57.2 ± 10.3^b
AEC	200	10.3 ± 2.8^b	44.6 ± 7.1	56.3 ± 9.2^b
AEC	400	11.3 ± 2.2^b	41.1 ± 5.3	54.7 ± 8.9^b
INDO	10	5.8 ± 3.1^c	39.4 ± 5.9	21.9 ± 8.1^c

n = 7, per group.

a Values represent mean ± SEM.

b p < 0.01 (one-way ANOVA and Turkey’s test), significantly different from control group.

c p < 0.001 (one-way ANOVA and Turkey’s test), significantly different from control group.

Figure 4. Effect of acute administration of vehicle, lyophilized aqueous extract obtained from C. icaco leaves (AEC; 100, 200 or 400 mg/kg, p.o.) or morphine (MOR, 5 mg/kg, i.p.) on hot plate test in mice. The bars shown the latency time to animals express pain behaviour, so each column represents the mean ± SEM (n = 8, per group). *p < 0.001 versus control (ANOVA followed by Tukey’s test).

Figure 5. Effect of acute administration of vehicle, lyophilized aqueous extract obtained from C. icaco leaves (AEC; 100, 200 or 400 mg/kg, p.o.) or indomethacin (IND, 10 mg/kg) on mechanical hyperalgesia induced by CG (300 μg/paw) (A) or TNF-α (100 pg/paw) (B). Each point represents the mean ± SEM of the variation of paw withdrawal threshold (in grams) to tactile stimulation of the ipsilateral hind paw. **p < 0.05 and ***p < 0.01, compared with vehicle-treated group (two-way ANOVA followed by Tukey’s test).

Figure 6. Effect of acute administration of vehicle, lyophilized aqueous extract obtained from C. icaco leaves (AEC; 100, 200 or 400 mg/kg, p.o.) or diazepam (DZP, 3 mg/kg, i.p.) on rota-rod test (A) or grip strength meter (B) in mice. ***p < 0.01, compared with vehicle-treated group (one-way ANOVA followed by Tukey’s test).