What is TB-500? |
TB-500 is a synthetic form of thymosin beta-4 (TB4), an endogenous human peptide that is made of 43 amino acids and can be found in virtually all cells of the body, especially in platelets and white blood cells . TB4 was first isolated in 1981 by Low and Goldstein from bovine thymus gland extract . The synthetic version, TB-500, has not been approved for human use and is available solely as a research chemical. It was first manufactured in the early 2010s for veterinary use. TB-500 has been used as a doping agent in horse racing and consecutively banned for providing an unfair advantage in that sport . Thymosin beta-4 and its derivatives, including TB-500, are likewise banned by the World Anti-Doping Agency (WADA) and thus prohibited for use by competitive athletes subject to the WADA Code and comparable national and regional regulatory bodies . TB-500 is nonetheless under active research for its potential effects on cell migration and tissue repair, formation of new blood vessels, maturation of stem cells, survival of various cell types, and anti-inflammatory action . TB-500 and thymosin beta-4 have poor oral bioavailability, and thus can only be administered via injections in experimental settings. Yet, a naturally occurring fragment of thymosin beta-4, called N-acetyl seryl-aspartyl-lysyl-proline (Ac-SDKP), is an orally active peptide thought to possess similar antifibrotic, anti-inflammatory, angiogenic properties, and effects on cell migration and survival . It has been investigated as an inhibitor of hematopoietic stem cell proliferation and a chemoprotective agent [9, 10]. Researchers may find the TB-500 fragment included in innovative TB-500 capsule formulas intended for tissue repair and recovery. |
What Does TB-500 Do? |
The mechanisms of action of TB-500 are still under investigation, but scientists already have some insight into the workings of its natural counterpart, thymosin beta-4. Thymosin beta-4 appears to work as an actin-binding protein that inhibits the polymerization of globular actin (G-actin) into filamentous actin (F-actin) . The process is called actin sequestration and results in upregulated G-actin levels Actin is a major component of the cellular cytoskeleton that provides structural support to cells and is involved in various cellular processes, including cell motility. Thymosin beta-4 appears to bind with actin primarily (but not only) via its central actin-binding domain (aa 17-23), also known as Ac-LKKTETQ . The prevention of F-actin polymerization by thymosin beta-4 alters the cellular cytoskeleton, which affects the ability of cells to move and change shape. This process has implications for various physiological and pathological processes where cell motility is crucial, such as wound healing, tissue regeneration, and cancer metastasis In addition, thymosin beta-4 can be found outside of cells (extracellularly) in blood plasma or in wound fluid. Research in blood vessel cells suggests that the application of extracellular thymosin beta-4 may also regulate processes such as cell motility and angiogenesis. It was found to act extracellularly by interacting with cell surface-located ATP synthase enzymes, cellular enzymes involved in the energy production of the cell Extracellular thymosin beta-4 may also get oxidized in sites of inflammation to thymosin beta-4 sulfoxide, and the latter is thought to have potent anti-inflammatory properties Thymosin beta-4 may likewise reduce inflammation by increasing the expression of microRNA-146a (miR-146a), thought to decrease the expression of two pro-inflammatory cytokines called L-1 receptor-associated kinase 1 (IRAK1) and tumor necrosis factor receptor-associated factor 6 (TRAF6) |
TB-500 Benefits | State of Research |
Research on TB-500 and its natural counterpart, thymosin beta-4, is still in the early stages. Limited clinical trials available, and the majority of studies are laboratory experiments performed in vitro or in test animals. With that in mind, explore some of the potential benefits associated with TB-500 and thymosin beta-4. |
