Well, if we're talking TV stars who went into MMA then there's The Green Ranger from Power Rangers.
https://en.wikipedia.org/wiki/Jason_David_Frank
Black belt in a bunch of TMAs (2 Karate styles, TKD, Judo), he went 4-0 in ammy MMA and 1-0 in pro MMA.
Not saying this guy could hang in the UFC, just that he actually took all that TMA experience and competed successfully under MMA rules.
Yes, he beat a bunch of cans but he sorta disproved the common notion that
"that TMA shit won't work in the cage", which so many MMA fans still hold today, despite seeing TMA-based guys rise to the very top once in a while.