Synthesis and antiinflammatory and analgesic activity of 5-aroyl-6-(methylthio)-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-ca rboxyl ic acids and 1-methyl-4-(methylthio)-5-aroylpyrrole-2-acetic acids

5-Aroyl-6-(methylthio)-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carb oxylic acids and 1-methyl-4-(methylthio)-5-aroylpyrrole-2-acetic acids were synthesized and assayed as antiinflammatory and analgesic agents. The majority of these compounds exhibit a surprisingly low level of antiinflammatory activity (rat carrageenan paw) but have considerable potency as analgesics (mouse phenylquinone writing). For example, the p-tolyl-substituted bicyclic and monocyclic compounds 44 and 58 are 301 and 66 times more potent than aspirin (mouse writhing) but only 3.4 and 1.5 times more potent than phenylbutazone in the antiinflammatory screen (rat paw).

Intraarticular injection of Propionibacterium acnes causes an erosive arthritis in rats

Formalin killed Propionibacterium acnes, was injected intraarticularly into the stifle joint of rats. The reaction was assessed by radiologic and histologic examination. A single injection induced a marginally erosive synovitis that receded by day 30. A second injection administered in the same joint resulted in tissue destruction that was evident radiographically. Treatment by dexamethasone and some disease modifying drugs, i.e. chloroquine, hydroxychloroquine, sodium aurothiomalate and cyclophosphamide, significantly inhibited cartilage and bone erosion while nonsteroidal antiinflammatory agents had no effect.