TA-65(recently identified as cycloastragenol) is not from Terminalia Arjuna but from Astragalus. I assume the TA there stands for Telomerase Activator. See the huge Astragalus, Astragalocide IV and telomerase thread.
But Terminalia Arjuna is definitely interesting stuff.
Thanks. I realized this after I wrote it. I used astragalus for a while and remembered that thread. I wonder why the wiki article made that claim ?