Estrogen is shown here. Steroids are a class of lipid hormones synthesized from cholesterol. They regulate metabolism, immune response, reproduction and other essential biological processes, the 1999 textbook Biochemistry notes.owever, they are most well-known for their anti-inflammatory effects. Cortisol is commonly used to treat a variety of allergic and autoimmune conditions including poison ivy, asthma, rheumatoid arthritis and transplant rejection, they act by depressing immune function on the molecular, cellular and tissue levels.