Mometasone furoate

In asthma, mometasone is believed to inhibit mast cells, eosinophils, basophils, and lymphocytes. There is also evidence of inhibition of histamine, leukotrienes, and cytokines.

Corticosteroids diffuse across cell membranes into the cytosol of cells where they bind to glucocorticoid receptors to produce their activity. Mometasone furoate has a particularly high receptor affinity compare to other corticosteroids, 22 times higher than that of dexamethasone. Mometasone furoate binding to a glucocorticoid receptor causes conformational changes in the receptor, separation from chaperones, and the receptor moves to the nucleus. Once at the nucleus, receptors dimerize and bind to a DNA sequence known as the glucocorticoid response element which either increases expression of anti-inflammatory molecules or inhibits expression of pro-inflammatory molecules (such as interleukins 4 and 5). Mometasone furoate also reduces inflammation by blocking transcription factors such as activator-protein-1 and nuclear factor kappa B (NF-kappaB).