Upside and Downside of Tumor Necrosis Factor Blockers for Treatment of Immune/Inflammatory Diseases

Tumor necrosis factor (TNF)-α, the most potent proinflammatory cytokine discovered to date, was first isolated in 1984 from human macrophage cells. Initially, it was thought to be a protein that was cytotoxic to tumor cells. But later, it was regarded as an agent that promotes inflammation and other chronic diseases found in humans. Currently, we know that the TNF superfamily (TNFS) has 19 members that perform a wide variety of functions via > 40 TNF receptors. Of TNFS members, TNF-α has been studied extensively and was found to be implicated in numerous autoimmune diseases, such as rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel disease, psoriasis, systemic lupus erythematosus, juvenile idiopathic arthritis, and diabetes. Thus, agents that can inhibit TNF-α have great potential for prevention and treatment of chronic diseases. To date, the U.S. Food and Drug Administration has approved many TNF-α blockers, such as etanercept, infliximab, adalimumab, certolizumab pegol, and golimumab. These agents can block TNF-α actions and be used to treat different diseases. However, the uses of TNF-α blockers are not without serious adverse effects. Therefore, natural TNF-α blockers are best for developing safe, efficacious, and affordable agents for prevention and treatment of chronic diseases. The current review details the TNFS, functions of TNF-α in normal and disease conditions, roles of TNF-α blockers, and advantages and disadvantages.