Dexamethasone Phosphate disodium (EGP437. Dex-Phos) is a water-soluble form of the synthetic glucocorticoid dexamethasone.

Dexamethasone regulates multiple transcription factors, including activator protein-1, nuclear factor-AT, and nuclear factor-kB, resulting in the activation and repression of key genes involved in the inflammatory response[1]. Dexamethasone potently inhibits granulocyte-macrophage colony stimulating factor (GM-CSF) release from A549 cells with EC50 of 2.2 nM. Dexamethasone (EC50=36 nM) induces transcription of the β2-receptor is found to correlate with glucocorticoid receptor (GR) DNA binding and occurred at 10-100 fold higher concentrations than the inhibition of GM-CSF release. Dexamethasone (IC50=0.5 nM) inhibits a 3×κB (NF-κB, IκBα, and I-κBβ), which is associated with inhibition of GM-CSF release.

Administering Dexamethasone at 2×5 mg/kg effectively reduces lipopolysaccharide (LPS)-induced inflammation. This treatment, particularly a single 10 mg/kg dose (i.p.), significantly lessens granulocyte mobilization and the spontaneous production of oxygen radicals in comparison to animals exposed to LPS and treated with saline. These benefits are pronounced when Dexamethasone is given both 1 hour before and after LPS inhalation, with granulocyte numbers in BALF dropping to those seen in healthy animals (exposed to an aerosol of water)[3]. However, rats receiving Dexamethasone show reduced food consumption and weight compared to control rats, and exhibit lower weights even compared to pair-fed rats with similar food intakes. Continuous Dexamethasone treatment for five days results in notable liver enlargement (+42%) and an increased liver-to-body weight ratio (+65%), while the gastrocnemius muscle's wet weight diminishes by 20% without affecting the muscle to body weight ratio (g/100 g body weight), suggesting muscle weight reduction aligns with overall body weight loss.