Salicylazosulfapyridine (Salazopyrin) effect on endotoxin-induced production of interleukin-1-like factor from human monocytes in vitro.

Monocytes (M phi) were simultaneously preincubated with salicylazosulfapyridine (Salazopyrin) (SAZ), 0.78-12.5 mM, and lipopolysaccharide from E. coli, 1 X 10(-9) g/ml. Presence of SAZ resulted in a dose-dependent decrease in the co-stimulatory activity in M phi culture supernatants, corresponding to a 50% reduction by SAZ, 2.0 mM. Co-stimulatory activity was estimated by the mitogen-induced thymocyte proliferation assay (THY assay). The results indicate an inhibitory effect of SAZ in vitro on the production of IL-1 and other possible co-stimulatory factors. This inhibitory effect was not due to decreased M phi viability, production of suppressive substances, or to drug interference with the THY assay. Equimolar preincubations with sulfapyridine, 5-aminosalicylic acid and N-acety-1-5-aminosalicylic acid were without effect on the production of co-stimulatory factors.