Essential oil composition and antinociceptive activity of Thymus capitatus

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 (V_CAP) 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.

Keywords:

• Pain
• glutamate
• action potential

Acknowledgements

The authors are grateful to CNPq and CAPES for providing financial support.

Disclosure statement

The authors report no declarations of interest.

Additional information

Funding

The authors are grateful to CNPq and CAPES for providing financial support.