Description
Cycloastragenol (TA-65), a small-triterpenoid purified from the root of an Asian medicinal herb, has currently received particular attention for its potential to regulate transcription of telomerase. TA-65 is capable to increase average telomere length and to decrease the percentage of critically short telomeres and DNA damage in MEFs that harbor critically short telomeres. The effects on telomerase appear to be in common with other triterpenoid saponins (ie, ginsenosides RG1 and Rg3). These compounds at concentrations from 1 to 20 μM were reported to protect against IL-1β-, H2O2-, and tert-butylhydroperoxide-induced senescence in human chondrocytes, endothelial progenitor cells and fibroblasts, respectively.
Biological Activity
Cycloastragenol, the aglycone derivative of astragaloside A, can be found in various species of Astragalus and is reported to activate telomerase. It has been shown to slow telomere loss, increase replicative capacity, and improve immune function in CD8+ T lymphocytes from HIV-1-infected patients.
Laboratory Procedures
Cycloastragenol is supplied as a crystalline solid. A stock solution may be made by dissolving the cycloastragenol in the solvent of choice. Cycloastragenol is soluble in organic solvents such as ethanol, DMSO, and dimethyl formamide (DMF), which should be purged with an inert gas. The solubility of cycloastragenol in these solvents is approximately 10, 3, and 25 mg/ml, respectively.
Cycloastragenol is sparingly soluble in aqueous buffers. For maximum solubility in aqueous buffers, cycloastragenol should first be dissolved in DMF and then diluted with the aqueous buffer of choice. Cycloastragenol has a solubility of approximately 0.25 mg/ml in a 1:8 solution of DMF:PBS (pH 7.2) using this method. We do not recommend storing the aqueous solution for more than one day.
Uses
Cycloastragenol is an aglycone derivative of astragaloside IV found in the root of Korean Astragalus membranaceus.
Definition
ChEBI: A sapogenin that is the aglycone derivative of astragaloside IV, a major saponin extracted from the root of Astragalus membranaceus.
