Antinociceptive activity of Thyme (Thymus vulgaris L.) and interactions with neurotropics and analgesics

Aleksandar Lazar Rašković,Ana Drago Tomas,Dušica Branko Rakić,Maja Petar Kvrgić,Anastazija Ðurica Stojšić-Milosavljević,Velibor Spasoje Čabarkapa,Milica Nada Paut Kusturica,Nebojša Petar Stilinović

doi:10.1590/s2175-97902020000318819

Abstract

The plant world represents an important source of potential therapeutic agents, but concomitant administration of herbal and conventional medications may result in interactions with subsequent beneficial or adverse effects. This study was designed to examine the analgesic effect of thyme tincture and thyme syrup, two commonly used thyme formulations, and their interactions with codeine, paracetamol, pentobarbital and diazepam in mice. The identification and quantification of thymol and carvacrol were carried out by GC/MS and GC/FID. The analgesic activity was studied using a hot plate method. Effects of thyme syrup on diazepam-induced motor coordination impairment in rotarod test and on pentobarbital-induced sleeping time were also determined. Thymol (175.3 µg/mL and 9.73 µg/mL) and carvacrol (10.54 µg/mL and 0.55 µg/mL) concentrations were measured in tincture and syrup, respectively. Thyme syrup and tincture exhibited effective analgesic activity in the hot plate pain model. Pretreatment with thyme formulations reduced analgesic activity of codeine, and potentiated the analgesic activity of paracetamol. Co-administration of thyme formulations has led to potentiation of diazepam and pentobarbital depressive central nervous system effects. Thyme formulations interacted with tested conventional drugs, probably through interference with their metabolic pathways and succeeding altered concentrations and pharmacological effects.

Highlights

The lack of a potent analgesic drugs with less severe side effects than the ones available prompted many investigators to turn to the plant-derived extracts and phytochemicals in search for the safe and effective analgesics (Rašković et al, 2015a)
Forced motor activity test and pentobarbital induced sleeping time test The results of this study showed that thyme syrup potentiated diazepam-induced motor coordination impairment in mice (Table III)
Content of thymol and carvacrol in studied formulations implies that the plant used in our study belongs to thymol chemotype, which is in accordance with previous study that identified chemical profile of essential oil from Thymus vulgaris collected in Serbia as being of the same chemotype (Nikolić et al, 2014)

Summary

Introduction

The lack of a potent analgesic drugs with less severe side effects than the ones available prompted many investigators to turn to the plant-derived extracts and phytochemicals in search for the safe and effective analgesics (Rašković et al, 2015a). Thyme (Thymus vulgaris L., Lamiaceae), a perennial herb native in. Studies examining thyme isolated constituents documented an analgesic potential, but information is scant on the pain-relieving properties of commercially available Thymus Vulgaris formulations. This deserves attention, as different extracts of other species of genus Thymus, Thymus broussonetii and Thymus kotschyanus, exerted an antinociceptive activity in various experimental pain models (Elhabazi et al, 2006, Nikoui et al, 2016)

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Results

Discussion

Conclusion