A study on the analgesic effects of four new derivatives of 3-hydroxy pyridine-4-one

Derivatives of pyridine-4-one are iron chelators with various biological activities including antifungal, anti-malarial, antiviral, anti-inflammatory and analgesic activities. This study was aimed to evaluate the analgesic effect of four new derivatives of 3-hydroxy pyridine-4-one in animal models. Acetic acid-induced writhing and formalin tests were used to assess the analgesic activity in male mice (18-22 g). Compound A (2.5-10 mg/kg), B (100-400 mg/kg), C and D (50-200 mg/kg) were administered intraperitoenally. Indomethacin and morphine were used as reference analgesic drugs. All tested compounds showed significant analgesia in acetic acid-induced writhing and the second phase of formalin test. All compounds except compound B also had analgesic activity in the first phase of formalin test. Among the investigated compounds, compound A which showed analgesic activity at doses of 2.5-10 mg/kg considered as the most potent analgesic compound. Structurally compound A lacks polar moieties such as −OH or −COOH and is less polar than the others. Therefore it seems that it has a better penetration into lipophilic sites of action.