While Thymosin Beta 4 (Thymosin β4) was isolated and characterized nearly 40 years ago, its potential benefits are still being revealed. Thymosin β4 is a peptide that plays a central role in repair, healing, and regeneration. While it was first isolated from the thymus gland (hence, its name), it is found naturally in many tissues of the body. Platelets and white blood cells have particularly high levels of thymosin β4. These facts are biologically important because platelets are the first substances to arrive at the site of injury and white blood cells are the major cells of the immune system.
When the body is injured, platelets, macrophages, and other cells release thymosin β4 at the site of the injury. Thymosin β4 acts at the injury site to stop cell suicide (i.e., apoptosis), reduce overly aggressive inflammation, and slow the growth of infectious microbes. Beyond these actions, however, thymosin β4 also signals stem cells to come to the injury site and differentiate into the cells that are needed for growth, healing, and renewal.
Goldstein and co-authors review the many benefits and potential uses of thymosin β4. In wound healing and repair, thymosin β4 helps new blood vessels and nerves form in injured tissue and, in fact, helps new, healthy tissue to grow. Thymosin β4 reduces the number of myofibroblasts in healing wounds—an action that decreases the formation of scar tissue. The anti-inflammatory actions of thymosin β4 reduce swelling, pain, and tissue damage.
Phase I clinical trials show that thymosin β4 preparations (e.g. eye gel) are safe and well-tolerated. Phase II trials show that thymosin β4 is safe and preliminarily effective in patients with serious pressure ulcers and venous stasis ulcers. Specifically, the wounds appeared to heal faster with treatment in randomized, double-blind, controlled trials. Thymosin β4 has also been used to treat diseases of the eye such as chronic dry eye and diabetic keratopathy. As more clinical trials and pivotal trials are conducted, the clinical applications of this incredible molecule are likely to expand.
Reference: Goldstein, A., et al. (2012). Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert Opinion on Biological Therapy. 2012. Volume 12, 2012 – Issue 1.