It looks like it may have used 3D Stroke and Shine to get that effect. Though, I don't really know exactly how it's done, the circle looks like a 3D Stroke effect. The "flames" look like 3D Strokes with Shine applied to them, but not sure if there are strokes lined up around the perimeter of the circle to get that effect or if it's some kind of opacity map.
I'm sure if I tried hard enough, I could get the look right... but the animation from the center out to the edges, I'm not sure about. I know that stroke can be made to travel along a path, so that's in the ball park, but to make the effect stroke each path in order like that I'm not sure about. Unless it's a half circle and mirrored.