Figure 2.

Cycloheximide derivatives differentially inhibit bacterial replication during infection and are not cytotoxic. (A) All inhibitors were tested in macrophage infection assays at concentrations ranging from 12.5 to 100 μM. The substances were added at the indicated concentrations 2 h post infection, and the bacterial replication was monitored by determining the colony forming units/milliliter (cfu/ml) 24 h post infection. The novel PPIase inhibitors MT_30.32 and MT_30.51 effectively suppressed bacterial replication during infection of differentiated THP-1 cells in a concentration dependent manner. The remaining seven derivatives had no effect at the highest concentration tested as demonstrated by the example MT_30.9, and were comparable to untreated infections containing only 1% (v/v) ethanol as the solvent at its final concentration. The graph depicts mean and SD of two independent experiments performed in duplicate as a representative of four biological replicates. (B) Differentiated THP-1 cells were incubated with 100 μM MT_30.32 or MT_30.51 for 24 h. After 20 h, alamar blue was added and cell viability was determined by measuring fluorescence at 590 nm. The medium of control cells was either free of additives (untreated) or contained 1% (v/v) EtOH as a solvent control. The graph shows the mean and SD of two independent experiments performed in triplicate.