What is the mechanism of action of corticosteroids in reducing inflammation?

Corticosteroids primarily exert their anti-inflammatory effects by inhibiting the expression of inflammatory genes. They achieve this through several mechanisms. First, corticosteroids enter cells and bind to glucocorticoid receptors, which then translocate to the nucleus. In the nucleus, this receptor complex can interact with specific regions of DNA, influencing the transcription of genes involved in the inflammatory response.

By inhibiting the transcription of pro-inflammatory cytokines, chemokines, adhesion molecules, and other mediators of inflammation, corticosteroids effectively reduce the recruitment and activation of leukocytes at the site of inflammation. This leads to a decreased inflammatory response. Additionally, corticosteroids can upregulate the expression of anti-inflammatory proteins, further augmenting their effects in dampening inflammation.

Other options describe incorrect mechanisms. For instance, increasing leukocyte activity or production of cytokines would exacerbate inflammation rather than diminish it. Similarly, promoting vasodilation would not contribute to the anti-inflammatory action of corticosteroids; in fact, corticosteroids often lead to vasoconstriction in certain contexts, reducing edema and inflammation.