Effects of fenoprofen and benoxaprofen on human lymphocytes: inhibition of tritiated thymidine uptake.

The effects of the related nonsteroidal anti-inflammatory agents, fenoprofen and benoxaprofen, on in vitro responses of normal human peripheral blood lymphocytes were examined. Drugs caused dose-related inhibition of stimulated cell responses. Fifty percent inhibition occurred at 400 microgram/ml calcium fenoprofen and 250 microgram/ml sodium benoxaprofen. Drugs affected not only responses to soluble phytomitogens but also responses to specific antigens and allogeneic lymphocytes. Numbers of viable cells in cultures with and without mitogens and drugs were similar at beginnings and ends of experiments, excluding drug-related cytotoxicity. Inhibition by drugs was greater when cells were cultured in medium alone than in medium with plasma. Cells that were exposed overnight to drugs and then washed and stimulated did not respond as well as did cells not exposed to drugs. These data indicated that fenoprofen and benoxaprofen exhibited noncytotoxic, incompletely reversible inhibition of nonspecific, specific, soluble and insoluble, mitogen-stimulated lymphocyte responses. These findings may pertain to the anti-inflammatory efficacy of these drugs.