Beclomethasone dipropionate

Beclomethasone dipropionate is a corticosteroid and prodrug that is rapidly activated by hydrolysis to the active monoester, 17 monopropionate (17-BMP), which mediates anti-inflammatory actions. 17-BMP has been shown in vitro to exhibit a binding affinity for the human glucocorticoid receptor which is approximately 13 times that of dexamethasone and 25 times that of beclomethasone dipropionate. Upon binding of the ligand, the glucocorticoid receptors dimerize and translocate into the nucleus, where they subsequently bind to glucocorticoid response elements (GRE) on glucocorticoid-responsive genes, leading to changes in transcription. There are several proposed mechanisms for the anti-inflammatory action of corticosteroids. Corticosteroids may work by increasing the transcription of genes coding for anti-inflammatory proteins, including lipocortin-1 and interleukin-10. Corticosteroids were also shown to inhibit the expression of multiple genes that encode pro-inflammatory factors, such as cytokines, chemokines, and adhesion molecules, that are activated during the chronic inflammatory process. This is thought to be due to the direct inhibitory interaction between activated glucocorticoid receptors and activated pro-inflammatory transcription factors, such as nuclear factor-kappa B and activator protein-1. Chronic inflammation is often characterized by enhanced expression of these transcription factors that bind to and activate coactivator molecules, which then acetylate core histones to switch on gene transcription to further amplify the inflammatory process. Corticosteroids suppress the multiple inflammatory gene expression by promoting histone deacetylation, resulting in tighter coiling of DNA and reduced access of transcription factors to their binding sites.