NAC restores intracellular GSH in RAW 264.7 cells incubated with CEES/LPS. Macrophages incubated with 50 ng/ml LPS or/and 500 μM CEES were simultaneously treated with or without 5 mM NAC (as indicated). Cell lysates were measured for reduced GSH after 4 hour incubation using the HPLC technique described in Materials and Methods. The GSH levels were normalized to an internal homocysteine standard. Mean values not sharing a common letter are significantly different (p < 0.05).