Evaluation of the analgesic effect of Thymus kotschyanus hydroalcoholic extract in male mice by formalin and tail flick tests

Document Type : Research Paper


1 Razi Institute for Drug Research, Iran University of Medical Sciences, Tehran, Iran

2 Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran

3 Department of Pharmacology, School of Medicine, International Campus, Tehran University of Medical Sciences, Tehran, Iran.


Background and Objective: Considering the wide side effects of synthetic pain killers, use of herbal drugs in folk medicine as analgesic agents has increased. In the present work, we tried to uncover the pharmacological potential of ethanolic extracts by using various animal models and also to explore the potent antinociceptive effect of the plant Thymus kotschyanus.
Materials and Methods: The ethanolic extract from the aerial part of Thymus kotschyanus after intraperitoneal administration at doses of 50, 100 and 200 mg/kg was evaluated against pain using formalin test and tail flick test.
Results: Thymus kotschyanus extract at doses of 100 mg/kg (p<0.05) and 200 mg/kg (p<0.001) induced analgesia in the early and late phases of the formalin test. Maximum analgesia in acute and late phases was experienced at a dose of 200 mg/kg, while at a dose of 50 mg/kg was ineffective. The extract at a dose of 200 mg/kg increased the antinociceptive activity in minutes 30 (p<0.01), 45, 60 and 75 (p<0.05) after formalin injection and also in tail-flick test in comparison to control. The significant effect for doses of 100 and 200 mg/kg after injection of Thymus kotschyanus was observed at minute 60.
Conclusion: The results obtained in this study highlight that aerial part extract of Thymus kotschyanus possesses analgesic properties in both acute and chronic inflammatory pain.