Background: NSAIDs are the most widely prescribed medications worldwide for their anti-inflammatory, antipyretic, and analgesic effects However, their chronic use can lead to several adverse drug events including GI toxicity. The selective COX-2 inhibitors developed as gastro-sparing NSAIDs also suffer from serious adverse effects which limit their efficacy. Objective: Local generation of reactive oxygen species is implicated in NSAID-mediated gastric ulceration and their combination with H2 antagonists like famotidine reduces the risk of ulcers. The objective of this work was to design and synthesize novel methanesulphonamido isoxazole derivatives by hybridizing the structural features of NSAIDs with those of antiulcer drugs (ranitidine, famotidine, etc.) to utilize a dual combination of anti-inflammatory activity and reducing (antioxidant) potential. Method: The designing process utilized three dimensional similarity studies and utilized an isoxazole core having a potential for anti-inflammatory as well as radical scavenging antioxidant activity. The compounds were assayed for their antiinflammatory activity in established in vivo models. The in vitro antioxidant activity was assessed in potassium ferricyanide reducing power (PFRAP) assay employing ascorbic acid as the standard drug. Results: Compounds (5, 6, 9 and 10) showed anti-inflammatory activity comparable to the standard drugs and were also found to be non-ulcerogenic at the test doses. Compounds 6-10 exhibited good antioxidant effect in the concentration range of 1.0-50.0 µmol/ml. The test compounds were also found to comply with the Lipinski rule suggesting good oral absorption. Conclusion: A new series of isoxazole based compounds is being reported with good anti-inflammatory activity coupled with antioxidant potential as gastro-sparing anti-inflammatory agents.

Background: NSAIDs are used as first-line drugs for treatment of various inflammatory disorders. Chronic use of NSAIDs is known to be associated with gastrointestinal and renal toxicity. Local generation of reactive oxygen species finally resulting in cellular apoptosis is one of the accepted mechanisms for NSAID-induced toxicity. Objective: The objective of the present study was to design and synthesize a series of 2-methane sulfonamido substituted arylthiazole derivatives by including structural features of combined antiulcer and anti-inflammatory activity utilizing as the structural core, thiazole nucleus with potential for antioxidant effect. Methods: Compounds were designed based on three dimensional and field similarity studies. The synthesized compounds were evaluated for their anti-inflammatory activity in carrageenan induced rat paw edema model. Rofecoxib and indomethacin were taken as standard drugs for comparison. The in vitro antioxidant activity was assessed in potassium ferricyanide reducing power (PFRAP) assay employing ascorbic acid as the standard drug. Results: The compounds 6 and 7 showed good anti-inflammatory activity comparable to the standard group and were also non ulcerogenic at the test doses. Compounds 1-7 displayed varying degrees of reducing power in the PFRAP) assay and the methanesulphonamido derivatives 4-7 showed the highest antioxidant activity (EC50 values 3.7-5.1 µmol/ml vs ascorbic acid 7.4 µmol/ml). Theoretical ADME profiling of the compounds based on selected physicochemical properties showed excellent compliance with Lipinski’s rule. Conclusion: A series of compounds have been designed and synthesized having dual antioxidant and anti-inflammatory activity with activities comparable to standard drugs.