The action of Clofazimine on the level of lysosomal enzymes of cultured macrophages.

Mouse peritoneal and calf alveolar macrophage cultures were exposed to various concentrations of Clofazimine, 3 (p-chloroanilino)-10-p-Chlorophenyl 2, 10-dihydro-2-isopropylimino, for 120 hr and an increase of four lysosomal enzymes were found with 0 . 3 micrograms/ml of the drug. In mouse peritoneal macrophage cultures, higher concentrations were toxic. Cycloheximide inhibited the lysosomal enzyme activity increase found. No change in enzymatic activity was observed when a lysosomal enriched granular fraction was incubated with various drug concentrations. Our results strongly suggest that Clofazimine at concentrations close to therapeutic serum levels induces de novo synthesis of lysosomal enzymes in macrophage cultures.