Antinociceptive effect of citronellal in mice

Figures & data

Figure 1.  Chemical structure of citronellal.

Figure 2.  Effect of citronellal (CTL) on pentobarbital-induced hypnosis in mice. The parameters evaluated were the onset of sleeping (A) and duration of sleeping (B). Values are mean ± SEM for 10 mice, *p < 0.05; **p < 0.01, as compared to vehicle (control), one-way ANOVA.

Table 1.  Effect of citronellal (CTL) or aspirin on writhing induced by acetic acid.

Treatment	Dose (mg/kg)	Number of writhings^a	% Inhibition
Vehicle	–	32.1 ± 9.3	–
CTL	50	12.4 ± 6.2^b	61.4^d
CTL	100	10.8 ± 5.9^b	66.4^d
CTL	200	5.8 ± 4.7^c	81.9^e
Aspirin	200	3.9 ± 2.5^c	87.8^e

n = 10.

^aValues represent mean ± SEM.

^bp < 0.05 (one-way ANOVA and Dunnett’s test), ^cp < 0.01 (one-way ANOVA and Dunnett’s test), ^dp < 0.01 (Fisher’s test), ^ep < 0.001 (Fisher’s test), significantly different from control.

Table 2.  Effect of citronellal (CTL) or indomethacin on formalin-induced pain.

Treatment	Dose (mg/kg)	Licking time (s)
		0–5 min		15–30 min
		Score of pain^a	% Inhibition	Score of pain^a	% Inhibition
Vehicle	–	82.9 ± 19.5	–	74.3 ± 21.1	–
CTL	50	47.3 ± 14.7^b	42.9^d	22.8 ± 10.7^c	69.5^d
CTL	100	43.9 ± 16.8^b	47.0^d	21.5 ± 11.3^c	71.1^d
CTL	200	27.5 ± 17.2^c	66.8^e	15.4 ± 7.3^c	79.2^d
Aspirin	200	35.4 ± 9.8^c	57.3^e	5.9 ± 5.6^c	92.1^e

n = 10.

^aValues represent mean ± SEM.

^bp < 0.05 (one-way ANOVA and Dunnett’s test), ^cp < 0.01 (one-way ANOVA and Dunnett’s test), ^dp < 0.01 (Fisher’s test), ^ep < 0.001 (Fisher’s test), significantly different from control.

Table 3.  Antinociceptive effect of citronellal (CTL) in the hot plate test in the absence and presence of naloxone in mice.

Treatment	Dose (mg/kg)	Reaction time (licking of hind paws) (s)^a
		Basal	0.5 h	1 h	1.5 h	2 h
Vehicle	–	6.7 ± 2.4	8.1 ± 2.5	7.2 ± 3.2	9.2 ± 3.7	10.1 ± 5.9
CTL	50	7.1 ± 3.2	10.9 ± 3.3	12.4 ± 3.5	13.9 ± 4.4	12.7 ± 5.5
CTL	100	8.0 ± 2.2	15.8 ± 4.7	19.3 ± 4.3^b	18.5 ± 4.9^b	15.0 ± 4.4
CTL	200	7.7 ± 2.9	17.7 ± 3.9^b	21.2 ± 5.1^b	20.3 ± 5.1^b	13.8 ± 5.9
CTL + naloxone	100 + 0.5	8.1 ± 3.1	11.9 ± 3.7	14.1 ± 4.9	12.4 ± 5.8	10.0 ± 3.9
CTL + naloxone	200 + 0.5	6.1 ± 3.4	14.4 ± 4.0	12.6 ± 3.8	15.1 ± 4.3	13.2 ± 4.2
Morphine	5	7.1 ± 2.8	26.5 ± 4.5^c	29.3 ± 3.5^c	28.7 ± 4.1^c	29.1 ± 5.9^c
Morphine + naloxone	5 + 0.5	5.9 ± 4.1	11.4 ± 4.4	12.7 ± 5.8	19.5 ± 4.9^b	13.7 ± 6.2

n = 10.

^aValues represent mean ± SEM.

^bp< 0.05 (one-way ANOVA and Dunnett’s test), ^cp< 0.01 (one-way ANOVA and Dunnett’s test), significantly different from control.