How do corticosteroids reduce inflammation?

Corticosteroids, specifically glucocorticoids, reduce inflammation through several complex cellular and molecular mechanisms:

• Enzyme Inhibition: They indirectly inhibit the activity of phospholipase A2, an enzyme essential for synthesizing inflammatory mediators like prostaglandins and leukotrienes. This process is mediated by lipocortin-1.1
• Gene Regulation: Upon entering a cell, these steroids bind to specific receptors. The resulting complex enters the cell nucleus, where it activates or inhibits the transcription of specific genes. This alters the production of proteins, including enzymes and structural proteins, that mediate the inflammatory response.2
• Cytokine and Immune Suppression: Glucocorticoids inhibit the production and action of inflammatory cytokines. At higher doses, they can impair immune system function, reducing the production of antibodies and dampening cell-mediated immune reactions.23

While these actions are highly effective for treating conditions like asthma and rheumatoid arthritis, they can lead to significant side effects with long-term use, such as those seen in Cushing syndrome.24