Antinociceptive and anti-inflammatory effects of the essential oil of Lippia hermannioides, an endemic species of Brazil

Abstract

Lippia hermannioides (Verbenaceae) is a species endemic to Brazil with reported antioxidant and antimicrobial activity. The objective of this study was to determine the chemical composition of the essential oil of L. hermannioides leaves (EOLH), using chromatographic and spectrometric methods, as well as its antinociceptive and anti-inflammatory potential by implementing of chemical and thermal nociception models. The results revealed germacrene D (18.39%) as the major compound of the essential oil, followed by bicyclogermacrene (11.72%), 1,8-cineole (11.24%), sabinene (10.38%), E-caryophyllene (8.33%), β-pinene (7.37%), and α-pinene (6.18%). Intraperitoneal administration of EOLH at doses of 300 and 2,000 mg.kg-1 showed no signs of toxicity in mice. EOLH doses of 75 and 300 mg.kg-1 did not affect the animals’ motor coordination in the rotarod test but reduced the number of abdominal writhing induced by acetic acid and decreased paw licking time in both phases of the formalin test. There was also an increased latency time in the hot plate test. These results indicate that this essential oil has antinociceptive and anti-inflammatory activity, thus supporting further research on the use of this phytotherapeutic resource in the health field.

Key words:
chemical composition; inflammation; pain; toxicity; volatile oil