Pleiotropy (drugs) can respond to them, because the endogenous ones are endocrine messengers. Pleiotropy (drugs) In pharmacology, pleiotropy includes all of a drug's actions other than those for which the agent was specifically developed. It may include adverse effects which are detrimental ones, but is often used to denote additional beneficial effects. For example, statins are HMG-CoA reductase inhibitors that primarily act by decreasing cholesterol synthesis, but which are believed to have other beneficial effects, including acting as antioxidants and stabilizing atherosclerotic plaques. Steroid drugs, such as prednisone and prednisolone, have pleiotropic effects, including systemic ones, for the same reason that endogenous
Lovastatin the β-hydroxy acid open ring form; which is the active form. Lovastatin and other statins have been studied for their chemopreventive and chemotherapeutic effects. No such effects were seen in the early studies. More recent investigations revealed some chemopreventive and therapeutic effects, for certain types of cancer, especially in combination of statins with other anticancer drugs. It is likely that these effect are mediated by the properties of statins to reduce proteasome activity, leading to an accumulation of cyclin-dependent kinase inhibitors p21 and p27, and to subsequent G-phase arrest, as seen in cells of different cancer lines. Compactin and lovastatin,