TB-500 (Thymosin B4 Acetate)
Also known as Thymosin beta-4, Tβ4, RGN-259
TB-500 is a trade name for synthetic thymosin beta-4, a 43-amino-acid peptide that binds monomeric actin. Researchers study thymosin beta-4 for roles in cell migration, wound repair, angiogenesis, and cardiac and corneal injury.
Clinical-stage research
Size
2 options- Catalog no.
- BT5
- Specification
- 5mg*10vials
- Per kit
- 10 vials
For laboratory research use only. Not for human or animal consumption. Buyers must be 21 or older.
Overview
Thymosin beta-4 (Tβ4) was first isolated from calf thymus and later identified as the main G-actin-sequestering peptide in mammalian cells. It is encoded by the TMSB4X gene and is abundant in platelets and white blood cells. The name TB-500 is used commercially for synthetic Tβ4, but a doping-control analysis identified the N-acetylated 17–23 fragment (Ac-LKKTETQ) in material sold under that name. Preclinical research covers skin wounds, myocardial infarction and corneal injury. Tβ4 has been tested in small clinical trials, mainly for dry eye. Tβ4 is not an approved drug.
Class: Actin-sequestering peptide (thymosin beta-4)
Mechanism of action
How the compound acts, as described in the literature.
Binds monomeric G-actin in a 1:1 complex and limits its polymerization, maintaining a pool of unpolymerized actin that cells draw on during migration and cytoskeletal remodeling.
In cardiac cells, Tβ4 formed a complex with PINCH and integrin-linked kinase that activated Akt, which was associated with greater cell migration and survival and improved function after coronary ligation in mice.
In rat skin wounds and keratinocyte assays, it increased keratinocyte migration, re-epithelialization, collagen deposition and angiogenesis.
Other studies report reduced NF-κB activation in corneal epithelial cells and mobilization of epicardial progenitor cells in adult mouse hearts.
Published research
Selected studies, each linked to its PubMed record. Summaries describe what the studies reported.
1999
Rodent study
PMID 10469335Thymosin beta4 accelerates wound healing.
Malinda KM, et al. · J Invest Dermatol
In rats with full-thickness skin wounds, Tβ4 increased re-epithelialization, wound contraction, collagen deposition and angiogenesis compared with saline, and stimulated keratinocyte migration two- to threefold in vitro.
2004
Mouse and in vitro study
PMID 15565145Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair.
Bock-Marquette I, et al. · Nature
Tβ4 promoted migration and survival of embryonic and postnatal cardiac cells through a PINCH–ILK–Akt complex; in mice after coronary artery ligation, it improved early cardiomyocyte survival and cardiac function.
2015
Phase 2 RCT
PMID 26056426Thymosin beta 4 ophthalmic solution for dry eye: a randomized, placebo-controlled, Phase II clinical trial conducted using the controlled adverse environment (CAE™) model.
Sosne G, et al. · Clin Ophthalmol
In 72 participants with moderate to severe dry eye, neither primary endpoint differed from placebo at day 29; the Tβ4 group showed lower discomfort during environmental challenge on day 28 and improved central and superior corneal staining.
Evidence & safety
What the research does not show, and the adverse events and regulatory status it reports.
Most evidence for thymosin beta-4 is preclinical; human trials have been small, and a phase 2 dry eye trial missed its primary endpoints, although no adverse events were recorded. The name TB-500 has also been applied to a short Tβ4 fragment with essentially no published human data. Elevated Tβ4 expression has been linked to tumor cell migration and metastasis in colorectal cancer studies; Tβ4 is unapproved and prohibited in sport by WADA.
Specifications
All sizes, exactly as catalogued.
| Catalog no. | Product | Specification | Vials per kit |
|---|---|---|---|
| BT5 | TB-500 (Thymosin B4 Acetate) | 5mg*10vials | 10 |
| BT10 | TB-500 (Thymosin B4 Acetate) | 10mg*10vials | 10 |
For laboratory research use only. Not for human or animal consumption. Not intended to diagnose, treat, cure or prevent any disease. Research summaries are provided for educational purposes and do not describe this product’s use.