Abstract
Background: Analgesics selectively relieve pain by acting either on central or peripheral pain pathways. Recently, studies have shown accumulating evidence to implicate N-methyl-d-aspartate receptors (NMDARs) mediation in central and peripheral sensitization and visceral pain leading to the possibility that NMDAR antagonists may be useful in the treatment of pain.

Aims and Objectives: (1) To evaluate analgesic activity of Pioglitazone (PIO) in mice. (2) To compare the analgesic activity of PIO with the standard drugs tramadol and aspirin, in mice.

Materials and Methods: Albino mice were divided into four groups, containing six animals (n = 6) in each group (control, standard, and test group). Group-I: Control received saline solution 2 ml/kg orally, Group-II: Standard 1 received tramadol at a dose of 10 mg/ kg intraperitoneal, Group-III: Standard 2 received aspirin at a dose of 300 mg/kg orally, and Group-IV: Test received PIO at a dose of 20 mg/kg orally. PIO and normal saline were administered 30 min before, whereas the tramadol and aspirin were administered 15 min before writhing and tail clip methods. The decrease in number of writhes and the delay in reaction time in tail clip method denoted the analgesic activity.

Results: PIO decreased the number of writhes and delayed the reaction time in tail clip method considerably when compared with control, but less when compared with standard drugs.

Conclusion: PIO exhibits analgesic activity in both chemical and mechanical pain models in albino mice.

Key words: Analgesic Activity; Pioglitazone; N-methyl-d-aspartate Receptor; Tail Flick Method; Acetic Acid-Induced Writhing Method