Interactions of aspirin and salicylic acid with prednisolone for inhibition of lymphocyte proliferation

The anti-inflammatory properties of salicylates and prednisolone were inves tigated using inhibition of in vitro phytohemagglutinin-stimulated lymphocy te proliferation in human whole blood from healthy male and female subjects . Steroids and salicylates are used in conjunction for the treatment of inf lammatory disorders such as rheumatoid arthritis and inhibit the proinflamm atory transcription factor, NT kappaB, by different mechanisms. Data genera ted using various combinations of these drugs were analyzed using isobologr ams and the universal surface response approach based on the Loewe additivi ty principle. The interaction between aspirin and prednisolone was mildly a ntagonistic while that between salicylic acid and prednisolone was modestly synergistic at therapeutic concentrations. Further, aspirin was slightly m ore potent in males, but the nature of the steroid-salicylate interaction w as similar across genders. This study helps rationalize part of the benefic ial effects of steroids and salicylates in treatment of inflammatory disord ers. (C) 2001 Elsevier Science B.V. All rights reserved.