Diisoporpylglutathione ester protects A549 cells from the cytotoxic effects of sulphur mustard

The A549 cell line was used to assess the ability of diisopropylglutathione (DIPE) to protect against a 100 mu M challenge dose of sulphur mustard (HD ) using gentian violet (GV), thiazolyl blue (MTT) and neutral red (NR) assa ys as indicators of cell culture viability. As part of a continuing study of the efficacy of protective nucleophiles as candidate treatments for HD poisoning, several different combinations of p rotectant and HD were used to determine the optimal means of protecting A54 9 cells fi om the effects of HD. It was found that DIPE (4 mM) could protec t cells against the effects of HD though for optimal effect, DIPE had to be present at the time of HD challenge. Cultures protected with DIPE were up to 2.9-fold more viable than HD exposed cells 48 h after HD challenge when using the GV, MTT and NR assays to assess viability. Observations by phase contrast microscopy of GV stained cultures confirmed these findings. Pretreating A549 cultures with DIPE for 1 h followed by its removal prior t o PID challenge did maintain cell viability, though at a relatively low lev el (only up to 1.4-fold more viable than HD only exposed cells). DIPE was a lso able to protect ND exposed A549 cultures when added to cell cultures at intervals of up to 12 to 15 min after the initial ND exposure, though viab ility tended to decrease over this period, so that at 1 h, addition of DIPE did not maintain the viability of the cultures. This is the first such report of the anti-HD protectant properties of DIPE in A549 cells. It is concluded that the protection observed against HD is p robably largely due to extracellular inactivation of HD by DIPE.