Essential oil composition and antinociceptive activity of Thymus capitatus

Figures & data

Table 1. Chemical composition of T. capitatus essential oil (EO).

			T. capitatus EO
			#	KI^a	Compound	Area^b (%)
1	778	2-Methyl-butanoic acid methyl ester				0.1
2	932	α-Thujene	0.7
3	939	α-Pinene	0.6
4	954	Camphene	0.2
5	982	β-Pinene	0.4
6	993	β-Myrcene	1.7
7	1008	α-Phellandrene	0.2
8	1015	p-Menth-1-(7),8-diene	0.1
9	1021	α-Terpinene	1.2
10	1033	p-Cymene	4.4
11	1035	Limonene	0.4
12	1052	trans-β-Ocimene	0.1
13	1063	γ-Terpinene	3.7
14	1072	Sabinene Hydrate	0.2
15	1091	α-Terpinolene	0.2
16	1100	Linalool	0.9
17	1126	α-Campholenal	0.1
18	1172	Borneol	0.4
19	1181	Terpinen-4-ol	0.8
20	1193	α-Terpineol	0.1
21	1248	Nerol	0.1
22	1255	Neral	0.1
23	1264	Carvone	0.1
24	1273	Geranial	0.1
25	1290	Thymol	0.3
26	1313	Carvacrol	79.9
27	1362	Thymol acetate	0.1
28	1425	Caryophyllene	2.3
29	1446	Aromadendrene	0.1
30	1460	α-Humulene	0.1
31	1511	β-Bisabol	0.2
32	1545	α-Cadinene	0.2
33	1589	Caryophyllene Oxide	0.2
Monoterpene hydrocarbons			13.7
Oxygenated monoterpenes			83.0
Sesquiterpenes			3.1
Others			0.1

KI: Kovat’s indices; RT: retention time.

^a Retention index (KI) relative to standard mixture of n-alkanes on SPB-5 column.

^b The numbering refers to elution order, and values (relative peak area percent) represent averages of 3 determinations.

Figure 1. Antinociceptive effect of T. capitatus EO in mice. The T. capitatus EO was administered in mice orally (3–12 mg/kg) 1 h before initiating the glutamate-induced nociception method. Control animals were treated with vehicle alone. Morphine (5 mg/kg) was used as a positive control. Values are expressed as mean ± S.E.M, n = 8. *p < 0.05, ***p < 0.001 vs. control (ANOVA followed by Dunnet’s test).

Figure 2. T. capitatus EO reversibly blocks the peripheral nerve excitability. (A) Representative CAP recordings obtained by the single sucrose gap technique after 5, 15 and 30 min of T. capitatus EO (500 μg/mL) incubation. After drug incubation, the nerve was washed out with the physiological solution for 30 min. Control records were obtained when sciatic nerves were submitted to the physiological solution only. Stimulation parameters were 6–10 V/0.1 ms. (B) Time- and concentration-dependent effects of T. capitatus EO (1–500 μg/mL) on CAP amplitude (V_CAP) during 30 min incubation followed by nerve washout (30 min). Values are expressed as mean ± S.E.M, n = 4. *p < 0.05; **p < 0.01; ***p < 0.001 vs. control (Student’s t-test).

Figure 3. Effects of T. capitatus on the depolarization and repolarization phases of the CAP. T. capitatus EO (TC, 100 μg/mL) was incubated in the rat sciatic nerve for 30 min followed by drug washout out with the physiological solution. The CAP parameters like (A) the depolarization velocity (DV_PAC), and (B) the time constant of repolarization (τ_rep), were quantified and compared to control. Values are expressed as mean ± S.E.M, n = 4. *p < 0.05 vs. control (Student’s t-test).