The Cerbera kernel contains several glycosides, with the most notable being cerberin.
Take a look at the structure of cerberin, then take a look at the structure of oleandrin, from Oleander.
There’s no hurry, I’ll wait. Do they look similar? Damned near identical, huh? Both have a steroid nucleus with a lactone moiety, and conjugated to a sugar, with the only difference being the position of the acetate group.
So no surprise when I tell you that the toxic effects of cerberin mirror those of oleandrin.