Anti-inflammatory Activity of 3-Thiazolyl Coumarins

3-Thiazolyl coumarins 1-33 along with coumarin scaffold (IC50 = 5.2 +/- 0.2 mu g/mL) were evaluated for in vitro antiinflammatory activity. Activity of compounds was investigated by looking their influence on oxidative burst activity of zymosan stimulated whole blood phagocytes by using a luminol enhanced chemiluminescence technique. Ibuprofen was used as standard drug (IC50 = 54.2 +/- 9.2 mu M). Four 3-thiazolyl coumarin derivatives 9 (IC50 = 31.0 +/- 2.5 mu g/mL), 13 (IC50 = 27.1 +/- 4.2 mu g/mL), 18 (IC50 = 5.6 +/- 2.6 mu g/mL), and 29 (IC50 = 1.9 +/- 1.0 mu g/mL) out of thirty-three demonstrated antiinflammatory activity as compared to the standard ibuprofen (IC50 = 11.2 +/- 1.9 mu g/mL). Especially, compound 29 showed many folds better activity as compared to coumarin and standard ibuprofen. Structure-activity relationship was also established. It is worth-mentioning that active analogs 9, 13, 18, and 29 were found to be non-toxic on NIH-3T3 mouse fibroblast cell line.