Essential oil composition and antinociceptive activity of Thymus capitatus

Juan Carlos Ramos Gonçalves,Danilo Andrade De Meneses,Aliny Pereira De Vasconcelos,Celyane Alves Piauilino,Fernanda Regina De Castro Almeida,Edoardo Marco Napoli,Giuseppe Ruberto,Demetrius Antônio Machado De Araújo

doi:10.1080/13880209.2017.1279672

Abstract

Context: The essential oil (EO) from Thymus capitatus Hoff. et Link. (Lamiaceae) has been traditionally used for its medicinal properties, such as anti-inflammatory, analgesic, antioxidant and antimicrobial properties.Objective: Characterize the constituents from T. capitatus EO and further evaluate the antinociceptive activity by in vivo and in vitro procedures.Materials and methods: Gas chromatography–mass spectrometry was used to identify and quantify the constituents of the T. capitatus EO. The antinociceptive activity was evaluated in vivo by the glutamate-induced nociception model in male Swiss mice (25 g), at doses of 3, 6 and 12 mg/kg, 1 h before evaluation of the licking time response (0–15 min). The mechanism of T. capitatus EO (1–500 μg/mL) on the isolated nerve excitability of Wistar rat (300 g) was assessed by the single sucrose technique.Results and discussion: The EO of T. capitatus presented 33 components, mainly monoterpenes and sesquiterpenes, carvacrol (ca. 80%) was its major constituent. T. capitatus EO induced antinociception in orally treated mice (3, 6, and 12 mg/kg) reducing the licking time from control (100.3 ± 11.9 s) to 84.8 ± 12.2, 62.7.6 ± 9.9, and 41.5 ± 12.7 s, respectively (n = 8; p < 0.05). Additionally, we have demonstrated that T. capitatus EO (500 μg/mL) decreased the compound action potential amplitude (VCAP) of about 80.0 ± 4.3% from control recordings (n = 4; p < 0.05). Such activity was presumably mediated through a voltage-gated Na+ channels.Conclusions: The present study demonstrated the antinociceptive activity of Thymus capitatus essential oil, which acts via peripheral nervous excitability blockade.

Highlights

The essential oils (EO) are volatile molecules generated by the secondary metabolism of higher plants and are produced by specialized secretory structures, such as glandular hairs and differentiated parenchyma cells (Lane et al 2010)
We stated that the oxygenated monoterpene carvacrol strongly characterizes the T. capitatus EO being its major constituent
The aforementioned aromatic profile is similar to Sicilian Thyme, as recently reported in a study on 30 samples collected throughout the Sicilian island, suggesting that Thymus capitatus [syn

Summary

Introduction

The essential oils (EO) are volatile molecules generated by the secondary metabolism of higher plants and are produced by specialized secretory structures, such as glandular hairs and differentiated parenchyma cells (Lane et al 2010). EO constituents belong mainly to two chemical groups: terpenoids (monoterpenes and sesquiterpenes of low molecular weight) and, to a lesser extent, phenylpropanoids (Regnault-Roger et al 2012). These EO have shown many biological activities, such as analgesic, anticonvulsant, anxiolytic, antioxidant, and antimicrobial properties (Faturi et al 2010; Pergolizzi et al 2010; Almeida et al 2011). The present study was designed to determine the major constituents from the T. capitatus EO and to evaluate its antinociceptive effects by in vivo and in vitro procedures

Objectives

Results

Conclusion