Efficacy of two FDA-approved drug combination in a mouse model of staphylococcal enterotoxin B-induced shock.

Staphylococcal enterotoxin B (SEB) causes lethal shock by potently stimulating the host immune response. Dexamethasone and N-acetyl cysteine (NAC) are anti-inflammatory and antioxidative drugs, respectively, which can independently modulate immune function. Dexamethasone was previously shown to be effective in preventing SEB-induced shock models only if administered early and in multiple doses for a long duration. In this study, dexamethasone and NAC were used in tandem and protected mice (75%) against SEB-induced lethal shock. Hypothermia and weight loss elicited by SEB were also diminished by this novel combination treatment. The levels of monocyte chemoattractant protein-1, interleukin-2, interleukin-6, and mouse gamma interferon in lung tissue after intranasal exposure to SEB were also significantly reduced in mice given a combination of dexamethasone and NAC versus controls.