Identification of volatile compounds of Clinopodium odorum (Lamiaceae):A comparison between HS-SPME and classic hydrodistillation / Identificación de compuestos volátiles de Clinopodium odorum (Lamiaceae): Una comparación entre HS-SPME ehidrodestilación clásica

In the present work an analytical methodology to micro scale based on the use of the HS-SPME/GC-MS to determine volatile compounds present in Clinopodium odorum (Griseb.) Harley (Lamiaceae)was optimized and settled differences and similarities with itsessential oil. A systematic description of the volatile components of flowers, stems, leaves and combined aerial parts (whole plant) was constructed via GC-MS analyses of HS-SPME adsorbed compounds and of essential oils obtained through hydrodistillation of the same tissues. Pulegone was the main component of both the HS-SPME analysis and essential oil analysis. In addition, piperitenone oxide andpiperitone oxide were the other main components in the essential oil whereas in the HS-SPME analysis cis-isopulegone and menthone prevailed. The HS-SPME method can achieve comparable results to those obtained by essential oil analysis, by using very fewer samples, ashorter extraction time and a much simpler procedure.

En el presente trabajo se ha optimizado una metodología analítica a micro-escala basada en HS-SPME/GC-MS para determinar los compuestos volátiles presentes en Clinopodium odorum (Griseb.) Harley (Lamiaceae), y se establecieron diferencias y similitudes con su aceite esencial. Se realizó una descripción sistemática de los componentes volátiles de flores, tallos, hojas y partes aéreas combinadas(planta entera) a partir de los análisis por GC-MS a través del sistema HS-SPME y de los aceites esenciales. Pulegona fue el componenteprincipal tanto del análisis por HS-SPME, como del aceite esencial. Además, el óxido de piperitenona y el óxido de piperitona eran los otroscomponentes principales en el aceite esencial mientras que en el análisis por HS-SPME, prevalecieron cis-isopulegona y mentona. El método de HS-SPME puede lograr resultados comparables a los obtenidos por el análisis de aceite esencial, mediante el uso de muestras de menor tamaño, un tiempo de extracción más corto y un procedimiento más simple.

Antinociceptive effects of the essential oil of Mentha x villosa leaf and its major constituent piperitenone oxide in mice

Mentha x villosa Huds (Labiatae) is an aromatic herb widely used in folk medicine. Since the essential oil of the herb has many pharmacological activities, including antispasmodic effects, we determined whether the oil and its major constituent, piperitenone oxide (PO), have antinociceptive activity. The essential oil of M. x villosa (EOMV) and PO administered orally at 200 mg/kg (vehicle: 0.1% Tween 80 in water) significantly reduced the writhings induced by acetic acid from control values of 59.5 ± 3.1 s (N = 10) to 31.9 ± 2.8 s (N = 10) and 23.8 ± 3.4 s (N = 10), respectively. When administered at 100 and 200 mg/kg, EOMV reduced the paw licking time for the second phase of the formalin test from the control value of 20.6 ± 2.1 s (N = 13) to 5.3 ± 2.2 s (N = 12) and 2.7 ± 1.2 s (N = 18), respectively. At 100 and 200 mg/kg, PO reduced this second phase to 8.3 ± 2.7 s (N = 12) and 3.0 ± 1.2 s (N = 10), respectively. This effect of EOMV and PO was not reversed by naloxone. EOMV and PO had no significant effect on the first phase of the formalin test. As evaluated by the hot-plate and tail immersion test, EOMV and PO, at doses up to 200 mg/kg, showed no analgesic activity. These results show that EOMV and PO have antinociceptive activity and suggest that this effect is probably an indirect anti-inflammatory effect, which does not involve the central nervous system.